More than 50 million US adults report experiencing chronic pain, with nearly 7% experiencing high-impact chronic pain.^1-3 Chronic pain negatively affects daily function, results in lost productivity, is a leading cause of disability, and is more prevalent among veterans compared with the general population.^1,2,4-6 Estimates from 2021 suggest the prevalence of chronic pain among veterans exceeds 30%; > 11% experienced high-impact chronic pain.¹

Primary care practitioners (PCPs) have a prominent role in chronic pain management. Pharmacologic options for treating pain, once a mainstay of therapy, present several challenges for patients and PCPs, including drug-drug interactions and adverse effects.⁷ The US opioid epidemic and shift to a biopsychosocial model of chronic pain care have increased emphasis on nonpharmacologic treatment options.^8,9 These include integrative modalities, which incorporate conventional approaches with an array of complementary health approaches.^10-12

Integrative therapy is a prominent feature in whole person care, which may be best exemplified by the US Department of Veterans Affairs (VA) Whole Health System of care.^13-14 Whole health empowers an individual to take charge of their health and well-being so they can “live their life to the fullest.”¹⁴ As implemented in the Veterans Health Administration (VHA), whole health includes the use of evidence-based complementary and integrative therapies, encompassing a multimodal pain management approach. Expanding the use of these therapies requires a better understanding of PCP and patient knowledge, interest, and use of integrative modalities for chronic pain.

METHODS

Using a cross-sectional survey design, PCPs and patients with chronic back pain affiliated with the VA Ann Arbor Healthcare System were invited to participate in separate but similar surveys to assess knowledge, interest, and use of nonpharmacologic integrative modalities for the treatment of chronic pain. In May, June, and July 2023, 78 PCPs received 3 email invitations to participate in an electronic (Qualtrics) survey. Patients were identified based on having an International Statistical Classification of Diseases, Tenth Revision code for low back pain (M54.5, M54.40, 41, 42, M54.89) on ≥ 2 outpatient encounters within 18 months (April 1, 2021, to March 31, 2023). A random sample of 200 patients was selected and sent a packet in September 2023 that included an introductory letter and a paper survey, along with a website link and QR code to complete the survey electronically if preferred. The introductory letter stated that participation is voluntary, had no impact on the health care currently received at the VA, and names are not attached to the survey, allowing them to remain anonymous. The packet also included a $10 gift card to encourage survey completion.

Both survey instruments are available upon request, were developed by the study team, and included a mix of yes/no questions, “select all that apply” items, Likert scale response items, and open-ended questions. For one question about which modalities they would like available, the respondent was instructed to select up to 5 modalities. The instruments were extensively pretested by members of the study team, which included 2 PCPs and a nonveteran with chronic back pain.

The list of integrative modalities included in the survey was derived from the tier 1 and tier 2 complementary and integrative health modalities identified in a VHA Directive on complementary and integrative health.^15,16 Tier 1 approaches are considered to have sufficient evidence and must be made available to veterans either within a VA medical facility or in the community. Tier 2 approaches are generally considered safe and may be made available but do not have sufficient evidence to mandate their provision. For participant ease, the integrative modalities were divided into 5 subgroups: manual therapies, energy/biofield therapies, mental health therapies, nutrition counseling, and movement therapies. The clinician survey assessed clinicians’ training and interest, clinical and personal use, and perceived barriers to providing integrative modalities for chronic pain. Professional and personal demographic data were also collected. Similarly, the patient survey assessed use of integrative therapies, perceptions of and interest in integrative modalities, and potential barriers to use. Demographic and health-related information was also collected.

Data analysis included descriptive statistics (eg, frequency counts, means, medians) and visual graphic displays. Separate analyses were conducted for clinicians and patients in addition to a comparative analysis of the use and potential interest in integrative modalities. Analysis were conducted using R software. This study was deemed nonresearch quality improvement by the VA Ann Arbor Healthcare System facility research oversight board and institutional review board approval was not solicited.

RESULTS

Twenty-eight clinicians completed the survey, yielding a participation rate of 36%. Participating clinicians had a median (IQR) age of 48 years (9.5), 15 self-identified as White (54%), 8 as Asian (29%), 15 as female (54%), 26 as non-Hispanic (93%), and 25 were medical doctors or doctors of osteopathy (89%). Nineteen (68%) worked at the main hospital outpatient clinic, and 9 practiced at community-based outpatient clinics (CBOCs). Thirteen respondents (46%) reported having no formal education or training in integrative approaches. Among those with prior training, 8 clinicians had nutrition counseling (29%) and 7 had psychologic therapy training (25%). Thirteen respondents (46%) also reported using integrative modalities for personal health needs: 8 used psychological therapies, 8 used movement therapies, 10 used integrative modalities for stress management or relaxation, and 8 used them for physical symptoms (Table 1).

Overall, 85 of 200 patients (43%) responded to the study survey. Two patients indicated they did not have chronic back pain and were excluded. Patients had a median (IQR) age of 66 (20) years, with 66 self-identifying as White (80%), 69 as male (83%), and 66 as non-Hispanic (80%). Forty-four patients (53%) received care at CBOCs. Forty-seven patients reported excellent, very good, or good overall health (57%), while 53 reported excellent, very good, or good mental health (64%). Fifty-nine patients reported back pain duration > 5 years (71%), and 67 (81%) indicated experiencing back pain flare-ups at least once per week over the previous 12 months. Sixty patients (72%) indicated they were somewhat or very interested in using integrative therapies as a back pain treatment; however, 40 patients (48%) indicated they had not received information about these therapies. Among those who indicated they had received information, the most frequently reported source was their PCP (41%). Most patients (72%) also reported feeling somewhat to very comfortable discussing integrative medicine therapies with their PCP.

Integrative Therapy Recommendations and Use

PCPs reported recommending multiple integrative modalities: 23 (82%) recommended cognitive-behavioral therapy, 22 (79%) recommended acupuncture, 21 (75%) recommended chiropractic, 19 (68%) recommended battlefield acupuncture, recommended massage 18 (64%), 17 (61%) recommended meditation or mindfulness, and 15 (54%) recommended movement therapies such as yoga or tai chi/qigong (Figure 1). The only therapies used by at least half of the patients were chiropractic used by 59 patients (71%) and acupuncture by 42 patients (51%). Thirty-eight patients (46%) reported massage use and 21 patients (25%) used cognitive-behavioral therapy (Table 2).

Integrative Therapies Desired

A majority of PCPs identified acupuncture (n = 20, 71%), chiropractic (n = 19, 68%), and massage (n = 19, 68%) as therapies they would most like to have available for patients with chronic pain (Figure 2). Similarly, patients identified massage (n = 42, 51%), chiropractic (n = 34, 41%), and acupuncture (n = 27, 33%) as most desired. Seventeen patients (21%) expressed interest in movement therapies.

Barriers to Integrative Therapies Use

When asked about barriers to use, 26 PCPs (93%) identified access to services as a somewhat or extremely likely barrier, and 22 identified time constraints (79%) (Table 3). However, 17 PCPs (61%) noted lack of familiarity, and 18 (64%) noted a lack of scientific evidence as barriers to recommending integrative modalities. Among patients, 33 (40%) indicated not knowing what services were available at their facility as a barrier, 32 (39%) were not familiar with specific therapies, and 21 (25%) indicated a lack of clarity about the benefits of a specific therapy. Only 14 patients (17%) indicated that there were no obstacles to use.

DISCUSSION

Use of integrative therapies, including complementary treatments, is an increasingly important part of chronic pain management. This survey study suggests VA PCPs are willing to recommend integrative therapies and patients with chronic back pain both desire and use several therapies. Moreover, both groups expressed interest in greater availability of similar therapies. The results also highlight key barriers, such as knowledge gaps, that should be addressed to increase the uptake of integrative modalities for managing chronic pain.

An increasing number of US adults are using complementary health approaches, an important component of integrative therapy.¹² This trend includes an increase in use for pain management, from 42.3% in 2002 to 49.2% in 2022; chiropractic care, acupuncture, and massage were most frequently used.¹² Similarly, chiropractic, acupuncture and massage were most often used by this sample of veterans with chronic back pain and were identified by the highest percentages of PCPs and patients as the therapies they would most like available.

There were areas where the opinions of patients and clinicians differed. As has been seen previously reported, clinicians largely recommended cognitive-behavioral therapy while patients showed less interest.¹⁷ Additionally, while patients expressed interest in the availability of movement therapies, such as yoga, PCPs expressed more interest in other strategies, such as trigger point injections. These differences may reflect true preference or a tendency for clinicians and patients to select therapies with which they are more familiar. Additional research is needed to better understand the acceptability and potential use of integrative health treatments across a broad array of therapeutic options.

Despite VHA policy requiring facilities to provide certain complementary and integrative health modalities, almost all PCPs identified access to services as a major obstacle.¹⁵ Based on evidence and a rigorous vetting process, services currently required on-site, via telehealth, or through community partners include acupuncture and battlefield acupuncture (battlefield auricular acupuncture), biofeedback, clinical hypnosis, guided imagery, medical massage therapy, medication, tai chi/qigong, and yoga. Optional approaches, which may be made available to veterans, include chiropractic and healing touch. Outside the VHA, some states have introduced or enacted legislation mandating insurance coverage of nonpharmacological pain treatments.¹⁸ However, these requirements and mandates do not help address challenges such as the availability of trained/qualified practitioners.^19,20 Ensuring access to complementary and integrative health treatments requires a more concerted effort to ensure that supply meets demand. It is also important to acknowledge the budgetary and physical space constraints that further limit access to services. Although expansion and integration of integrative medicine services remain a priority within the VA Whole Health program, implementation is contingent on available financial and infrastructure resources.

Time was also identified by PCPs as a barrier to recommending integrative therapies to patients. Developing and implementing time-efficient communication strategies for patient education such as concise talking points and informational handouts could help address this barrier. Furthermore, leveraging existing programs and engaging the entire health care team in patient education and referral could help increase integrative and complementary therapy uptake and use.

Although access and time were identified as major barriers, these findings also suggest that PCP and patient knowledge are another target area for enhancing the use of complementary and integrative therapies. Like prior research, most clinicians identified a lack of familiarity with certain services and a lack of scientific evidence as extremely or somewhat likely to affect their ability to offer integrative services to patients with chronic pain.²¹ Likewise, about 40% of patients identified being unfamiliar with a specific therapy as one of the major obstacles to receiving integrative therapies, with a similar number identifying PCPs as a source of information. The lack of familiarity may be due in part to the evolving nomenclature, with terms such as alternative, complementary, and integrative used to describe approaches outside what is often considered conventional medicine.¹⁰ On the other hand, there has also been considerable expansion in the number of therapies within this domain, along with an expanding evidence base. This suggests a need for targeted educational strategies for clinicians and patients, which can be rapidly deployed and continuously adapted as new therapies and evidence emerge.

Limitations

There are some inherent limitations with a survey-based approach, including sampling, non-response, and social desirability biases. In addition, this study only included PCPs and patients affiliated with a single VA medical center. Steps to mitigate these limitations included maintaining survey anonymity and reporting information about respondent characteristics to enhance transparency about the representativeness of the study findings.

CONCLUSIONS

Expanding the use of nonpharmacological pain treatments, including integrative modalities, is essential for safe and effective chronic pain management and reducing opioid use. Our findings show that VA PCPs and patients with chronic back pain are interested in and have some experience with certain integrative therapies. However, even within the context of a health care system that supports the use of integrative therapies for chronic pain as part of whole person care, increasing uptake will require addressing access and time-related constraints as well as ongoing clinician and patient education.

More than 50 million US adults report experiencing chronic pain, with nearly 7% experiencing high-impact chronic pain.^1-3 Chronic pain negatively affects daily function, results in lost productivity, is a leading cause of disability, and is more prevalent among veterans compared with the general population.^1,2,4-6 Estimates from 2021 suggest the prevalence of chronic pain among veterans exceeds 30%; > 11% experienced high-impact chronic pain.¹

Primary care practitioners (PCPs) have a prominent role in chronic pain management. Pharmacologic options for treating pain, once a mainstay of therapy, present several challenges for patients and PCPs, including drug-drug interactions and adverse effects.⁷ The US opioid epidemic and shift to a biopsychosocial model of chronic pain care have increased emphasis on nonpharmacologic treatment options.^8,9 These include integrative modalities, which incorporate conventional approaches with an array of complementary health approaches.^10-12

Integrative therapy is a prominent feature in whole person care, which may be best exemplified by the US Department of Veterans Affairs (VA) Whole Health System of care.^13-14 Whole health empowers an individual to take charge of their health and well-being so they can “live their life to the fullest.”¹⁴ As implemented in the Veterans Health Administration (VHA), whole health includes the use of evidence-based complementary and integrative therapies, encompassing a multimodal pain management approach. Expanding the use of these therapies requires a better understanding of PCP and patient knowledge, interest, and use of integrative modalities for chronic pain.

METHODS

Using a cross-sectional survey design, PCPs and patients with chronic back pain affiliated with the VA Ann Arbor Healthcare System were invited to participate in separate but similar surveys to assess knowledge, interest, and use of nonpharmacologic integrative modalities for the treatment of chronic pain. In May, June, and July 2023, 78 PCPs received 3 email invitations to participate in an electronic (Qualtrics) survey. Patients were identified based on having an International Statistical Classification of Diseases, Tenth Revision code for low back pain (M54.5, M54.40, 41, 42, M54.89) on ≥ 2 outpatient encounters within 18 months (April 1, 2021, to March 31, 2023). A random sample of 200 patients was selected and sent a packet in September 2023 that included an introductory letter and a paper survey, along with a website link and QR code to complete the survey electronically if preferred. The introductory letter stated that participation is voluntary, had no impact on the health care currently received at the VA, and names are not attached to the survey, allowing them to remain anonymous. The packet also included a $10 gift card to encourage survey completion.

Both survey instruments are available upon request, were developed by the study team, and included a mix of yes/no questions, “select all that apply” items, Likert scale response items, and open-ended questions. For one question about which modalities they would like available, the respondent was instructed to select up to 5 modalities. The instruments were extensively pretested by members of the study team, which included 2 PCPs and a nonveteran with chronic back pain.

The list of integrative modalities included in the survey was derived from the tier 1 and tier 2 complementary and integrative health modalities identified in a VHA Directive on complementary and integrative health.^15,16 Tier 1 approaches are considered to have sufficient evidence and must be made available to veterans either within a VA medical facility or in the community. Tier 2 approaches are generally considered safe and may be made available but do not have sufficient evidence to mandate their provision. For participant ease, the integrative modalities were divided into 5 subgroups: manual therapies, energy/biofield therapies, mental health therapies, nutrition counseling, and movement therapies. The clinician survey assessed clinicians’ training and interest, clinical and personal use, and perceived barriers to providing integrative modalities for chronic pain. Professional and personal demographic data were also collected. Similarly, the patient survey assessed use of integrative therapies, perceptions of and interest in integrative modalities, and potential barriers to use. Demographic and health-related information was also collected.

Data analysis included descriptive statistics (eg, frequency counts, means, medians) and visual graphic displays. Separate analyses were conducted for clinicians and patients in addition to a comparative analysis of the use and potential interest in integrative modalities. Analysis were conducted using R software. This study was deemed nonresearch quality improvement by the VA Ann Arbor Healthcare System facility research oversight board and institutional review board approval was not solicited.

RESULTS

Twenty-eight clinicians completed the survey, yielding a participation rate of 36%. Participating clinicians had a median (IQR) age of 48 years (9.5), 15 self-identified as White (54%), 8 as Asian (29%), 15 as female (54%), 26 as non-Hispanic (93%), and 25 were medical doctors or doctors of osteopathy (89%). Nineteen (68%) worked at the main hospital outpatient clinic, and 9 practiced at community-based outpatient clinics (CBOCs). Thirteen respondents (46%) reported having no formal education or training in integrative approaches. Among those with prior training, 8 clinicians had nutrition counseling (29%) and 7 had psychologic therapy training (25%). Thirteen respondents (46%) also reported using integrative modalities for personal health needs: 8 used psychological therapies, 8 used movement therapies, 10 used integrative modalities for stress management or relaxation, and 8 used them for physical symptoms (Table 1).

Overall, 85 of 200 patients (43%) responded to the study survey. Two patients indicated they did not have chronic back pain and were excluded. Patients had a median (IQR) age of 66 (20) years, with 66 self-identifying as White (80%), 69 as male (83%), and 66 as non-Hispanic (80%). Forty-four patients (53%) received care at CBOCs. Forty-seven patients reported excellent, very good, or good overall health (57%), while 53 reported excellent, very good, or good mental health (64%). Fifty-nine patients reported back pain duration > 5 years (71%), and 67 (81%) indicated experiencing back pain flare-ups at least once per week over the previous 12 months. Sixty patients (72%) indicated they were somewhat or very interested in using integrative therapies as a back pain treatment; however, 40 patients (48%) indicated they had not received information about these therapies. Among those who indicated they had received information, the most frequently reported source was their PCP (41%). Most patients (72%) also reported feeling somewhat to very comfortable discussing integrative medicine therapies with their PCP.

Integrative Therapy Recommendations and Use

PCPs reported recommending multiple integrative modalities: 23 (82%) recommended cognitive-behavioral therapy, 22 (79%) recommended acupuncture, 21 (75%) recommended chiropractic, 19 (68%) recommended battlefield acupuncture, recommended massage 18 (64%), 17 (61%) recommended meditation or mindfulness, and 15 (54%) recommended movement therapies such as yoga or tai chi/qigong (Figure 1). The only therapies used by at least half of the patients were chiropractic used by 59 patients (71%) and acupuncture by 42 patients (51%). Thirty-eight patients (46%) reported massage use and 21 patients (25%) used cognitive-behavioral therapy (Table 2).

Integrative Therapies Desired

A majority of PCPs identified acupuncture (n = 20, 71%), chiropractic (n = 19, 68%), and massage (n = 19, 68%) as therapies they would most like to have available for patients with chronic pain (Figure 2). Similarly, patients identified massage (n = 42, 51%), chiropractic (n = 34, 41%), and acupuncture (n = 27, 33%) as most desired. Seventeen patients (21%) expressed interest in movement therapies.

Barriers to Integrative Therapies Use

When asked about barriers to use, 26 PCPs (93%) identified access to services as a somewhat or extremely likely barrier, and 22 identified time constraints (79%) (Table 3). However, 17 PCPs (61%) noted lack of familiarity, and 18 (64%) noted a lack of scientific evidence as barriers to recommending integrative modalities. Among patients, 33 (40%) indicated not knowing what services were available at their facility as a barrier, 32 (39%) were not familiar with specific therapies, and 21 (25%) indicated a lack of clarity about the benefits of a specific therapy. Only 14 patients (17%) indicated that there were no obstacles to use.

DISCUSSION

Use of integrative therapies, including complementary treatments, is an increasingly important part of chronic pain management. This survey study suggests VA PCPs are willing to recommend integrative therapies and patients with chronic back pain both desire and use several therapies. Moreover, both groups expressed interest in greater availability of similar therapies. The results also highlight key barriers, such as knowledge gaps, that should be addressed to increase the uptake of integrative modalities for managing chronic pain.

An increasing number of US adults are using complementary health approaches, an important component of integrative therapy.¹² This trend includes an increase in use for pain management, from 42.3% in 2002 to 49.2% in 2022; chiropractic care, acupuncture, and massage were most frequently used.¹² Similarly, chiropractic, acupuncture and massage were most often used by this sample of veterans with chronic back pain and were identified by the highest percentages of PCPs and patients as the therapies they would most like available.

There were areas where the opinions of patients and clinicians differed. As has been seen previously reported, clinicians largely recommended cognitive-behavioral therapy while patients showed less interest.¹⁷ Additionally, while patients expressed interest in the availability of movement therapies, such as yoga, PCPs expressed more interest in other strategies, such as trigger point injections. These differences may reflect true preference or a tendency for clinicians and patients to select therapies with which they are more familiar. Additional research is needed to better understand the acceptability and potential use of integrative health treatments across a broad array of therapeutic options.

Despite VHA policy requiring facilities to provide certain complementary and integrative health modalities, almost all PCPs identified access to services as a major obstacle.¹⁵ Based on evidence and a rigorous vetting process, services currently required on-site, via telehealth, or through community partners include acupuncture and battlefield acupuncture (battlefield auricular acupuncture), biofeedback, clinical hypnosis, guided imagery, medical massage therapy, medication, tai chi/qigong, and yoga. Optional approaches, which may be made available to veterans, include chiropractic and healing touch. Outside the VHA, some states have introduced or enacted legislation mandating insurance coverage of nonpharmacological pain treatments.¹⁸ However, these requirements and mandates do not help address challenges such as the availability of trained/qualified practitioners.^19,20 Ensuring access to complementary and integrative health treatments requires a more concerted effort to ensure that supply meets demand. It is also important to acknowledge the budgetary and physical space constraints that further limit access to services. Although expansion and integration of integrative medicine services remain a priority within the VA Whole Health program, implementation is contingent on available financial and infrastructure resources.

Time was also identified by PCPs as a barrier to recommending integrative therapies to patients. Developing and implementing time-efficient communication strategies for patient education such as concise talking points and informational handouts could help address this barrier. Furthermore, leveraging existing programs and engaging the entire health care team in patient education and referral could help increase integrative and complementary therapy uptake and use.

Although access and time were identified as major barriers, these findings also suggest that PCP and patient knowledge are another target area for enhancing the use of complementary and integrative therapies. Like prior research, most clinicians identified a lack of familiarity with certain services and a lack of scientific evidence as extremely or somewhat likely to affect their ability to offer integrative services to patients with chronic pain.²¹ Likewise, about 40% of patients identified being unfamiliar with a specific therapy as one of the major obstacles to receiving integrative therapies, with a similar number identifying PCPs as a source of information. The lack of familiarity may be due in part to the evolving nomenclature, with terms such as alternative, complementary, and integrative used to describe approaches outside what is often considered conventional medicine.¹⁰ On the other hand, there has also been considerable expansion in the number of therapies within this domain, along with an expanding evidence base. This suggests a need for targeted educational strategies for clinicians and patients, which can be rapidly deployed and continuously adapted as new therapies and evidence emerge.

Limitations

There are some inherent limitations with a survey-based approach, including sampling, non-response, and social desirability biases. In addition, this study only included PCPs and patients affiliated with a single VA medical center. Steps to mitigate these limitations included maintaining survey anonymity and reporting information about respondent characteristics to enhance transparency about the representativeness of the study findings.

CONCLUSIONS

Expanding the use of nonpharmacological pain treatments, including integrative modalities, is essential for safe and effective chronic pain management and reducing opioid use. Our findings show that VA PCPs and patients with chronic back pain are interested in and have some experience with certain integrative therapies. However, even within the context of a health care system that supports the use of integrative therapies for chronic pain as part of whole person care, increasing uptake will require addressing access and time-related constraints as well as ongoing clinician and patient education.

More than 50 million US adults report experiencing chronic pain, with nearly 7% experiencing high-impact chronic pain.^1-3 Chronic pain negatively affects daily function, results in lost productivity, is a leading cause of disability, and is more prevalent among veterans compared with the general population.^1,2,4-6 Estimates from 2021 suggest the prevalence of chronic pain among veterans exceeds 30%; > 11% experienced high-impact chronic pain.¹

Primary care practitioners (PCPs) have a prominent role in chronic pain management. Pharmacologic options for treating pain, once a mainstay of therapy, present several challenges for patients and PCPs, including drug-drug interactions and adverse effects.⁷ The US opioid epidemic and shift to a biopsychosocial model of chronic pain care have increased emphasis on nonpharmacologic treatment options.^8,9 These include integrative modalities, which incorporate conventional approaches with an array of complementary health approaches.^10-12

Integrative therapy is a prominent feature in whole person care, which may be best exemplified by the US Department of Veterans Affairs (VA) Whole Health System of care.^13-14 Whole health empowers an individual to take charge of their health and well-being so they can “live their life to the fullest.”¹⁴ As implemented in the Veterans Health Administration (VHA), whole health includes the use of evidence-based complementary and integrative therapies, encompassing a multimodal pain management approach. Expanding the use of these therapies requires a better understanding of PCP and patient knowledge, interest, and use of integrative modalities for chronic pain.

METHODS

Using a cross-sectional survey design, PCPs and patients with chronic back pain affiliated with the VA Ann Arbor Healthcare System were invited to participate in separate but similar surveys to assess knowledge, interest, and use of nonpharmacologic integrative modalities for the treatment of chronic pain. In May, June, and July 2023, 78 PCPs received 3 email invitations to participate in an electronic (Qualtrics) survey. Patients were identified based on having an International Statistical Classification of Diseases, Tenth Revision code for low back pain (M54.5, M54.40, 41, 42, M54.89) on ≥ 2 outpatient encounters within 18 months (April 1, 2021, to March 31, 2023). A random sample of 200 patients was selected and sent a packet in September 2023 that included an introductory letter and a paper survey, along with a website link and QR code to complete the survey electronically if preferred. The introductory letter stated that participation is voluntary, had no impact on the health care currently received at the VA, and names are not attached to the survey, allowing them to remain anonymous. The packet also included a $10 gift card to encourage survey completion.

Both survey instruments are available upon request, were developed by the study team, and included a mix of yes/no questions, “select all that apply” items, Likert scale response items, and open-ended questions. For one question about which modalities they would like available, the respondent was instructed to select up to 5 modalities. The instruments were extensively pretested by members of the study team, which included 2 PCPs and a nonveteran with chronic back pain.

The list of integrative modalities included in the survey was derived from the tier 1 and tier 2 complementary and integrative health modalities identified in a VHA Directive on complementary and integrative health.^15,16 Tier 1 approaches are considered to have sufficient evidence and must be made available to veterans either within a VA medical facility or in the community. Tier 2 approaches are generally considered safe and may be made available but do not have sufficient evidence to mandate their provision. For participant ease, the integrative modalities were divided into 5 subgroups: manual therapies, energy/biofield therapies, mental health therapies, nutrition counseling, and movement therapies. The clinician survey assessed clinicians’ training and interest, clinical and personal use, and perceived barriers to providing integrative modalities for chronic pain. Professional and personal demographic data were also collected. Similarly, the patient survey assessed use of integrative therapies, perceptions of and interest in integrative modalities, and potential barriers to use. Demographic and health-related information was also collected.

Data analysis included descriptive statistics (eg, frequency counts, means, medians) and visual graphic displays. Separate analyses were conducted for clinicians and patients in addition to a comparative analysis of the use and potential interest in integrative modalities. Analysis were conducted using R software. This study was deemed nonresearch quality improvement by the VA Ann Arbor Healthcare System facility research oversight board and institutional review board approval was not solicited.

RESULTS

Twenty-eight clinicians completed the survey, yielding a participation rate of 36%. Participating clinicians had a median (IQR) age of 48 years (9.5), 15 self-identified as White (54%), 8 as Asian (29%), 15 as female (54%), 26 as non-Hispanic (93%), and 25 were medical doctors or doctors of osteopathy (89%). Nineteen (68%) worked at the main hospital outpatient clinic, and 9 practiced at community-based outpatient clinics (CBOCs). Thirteen respondents (46%) reported having no formal education or training in integrative approaches. Among those with prior training, 8 clinicians had nutrition counseling (29%) and 7 had psychologic therapy training (25%). Thirteen respondents (46%) also reported using integrative modalities for personal health needs: 8 used psychological therapies, 8 used movement therapies, 10 used integrative modalities for stress management or relaxation, and 8 used them for physical symptoms (Table 1).

Overall, 85 of 200 patients (43%) responded to the study survey. Two patients indicated they did not have chronic back pain and were excluded. Patients had a median (IQR) age of 66 (20) years, with 66 self-identifying as White (80%), 69 as male (83%), and 66 as non-Hispanic (80%). Forty-four patients (53%) received care at CBOCs. Forty-seven patients reported excellent, very good, or good overall health (57%), while 53 reported excellent, very good, or good mental health (64%). Fifty-nine patients reported back pain duration > 5 years (71%), and 67 (81%) indicated experiencing back pain flare-ups at least once per week over the previous 12 months. Sixty patients (72%) indicated they were somewhat or very interested in using integrative therapies as a back pain treatment; however, 40 patients (48%) indicated they had not received information about these therapies. Among those who indicated they had received information, the most frequently reported source was their PCP (41%). Most patients (72%) also reported feeling somewhat to very comfortable discussing integrative medicine therapies with their PCP.

Integrative Therapy Recommendations and Use

PCPs reported recommending multiple integrative modalities: 23 (82%) recommended cognitive-behavioral therapy, 22 (79%) recommended acupuncture, 21 (75%) recommended chiropractic, 19 (68%) recommended battlefield acupuncture, recommended massage 18 (64%), 17 (61%) recommended meditation or mindfulness, and 15 (54%) recommended movement therapies such as yoga or tai chi/qigong (Figure 1). The only therapies used by at least half of the patients were chiropractic used by 59 patients (71%) and acupuncture by 42 patients (51%). Thirty-eight patients (46%) reported massage use and 21 patients (25%) used cognitive-behavioral therapy (Table 2).

Integrative Therapies Desired

A majority of PCPs identified acupuncture (n = 20, 71%), chiropractic (n = 19, 68%), and massage (n = 19, 68%) as therapies they would most like to have available for patients with chronic pain (Figure 2). Similarly, patients identified massage (n = 42, 51%), chiropractic (n = 34, 41%), and acupuncture (n = 27, 33%) as most desired. Seventeen patients (21%) expressed interest in movement therapies.

Barriers to Integrative Therapies Use

When asked about barriers to use, 26 PCPs (93%) identified access to services as a somewhat or extremely likely barrier, and 22 identified time constraints (79%) (Table 3). However, 17 PCPs (61%) noted lack of familiarity, and 18 (64%) noted a lack of scientific evidence as barriers to recommending integrative modalities. Among patients, 33 (40%) indicated not knowing what services were available at their facility as a barrier, 32 (39%) were not familiar with specific therapies, and 21 (25%) indicated a lack of clarity about the benefits of a specific therapy. Only 14 patients (17%) indicated that there were no obstacles to use.

DISCUSSION

Use of integrative therapies, including complementary treatments, is an increasingly important part of chronic pain management. This survey study suggests VA PCPs are willing to recommend integrative therapies and patients with chronic back pain both desire and use several therapies. Moreover, both groups expressed interest in greater availability of similar therapies. The results also highlight key barriers, such as knowledge gaps, that should be addressed to increase the uptake of integrative modalities for managing chronic pain.

An increasing number of US adults are using complementary health approaches, an important component of integrative therapy.¹² This trend includes an increase in use for pain management, from 42.3% in 2002 to 49.2% in 2022; chiropractic care, acupuncture, and massage were most frequently used.¹² Similarly, chiropractic, acupuncture and massage were most often used by this sample of veterans with chronic back pain and were identified by the highest percentages of PCPs and patients as the therapies they would most like available.

There were areas where the opinions of patients and clinicians differed. As has been seen previously reported, clinicians largely recommended cognitive-behavioral therapy while patients showed less interest.¹⁷ Additionally, while patients expressed interest in the availability of movement therapies, such as yoga, PCPs expressed more interest in other strategies, such as trigger point injections. These differences may reflect true preference or a tendency for clinicians and patients to select therapies with which they are more familiar. Additional research is needed to better understand the acceptability and potential use of integrative health treatments across a broad array of therapeutic options.

Despite VHA policy requiring facilities to provide certain complementary and integrative health modalities, almost all PCPs identified access to services as a major obstacle.¹⁵ Based on evidence and a rigorous vetting process, services currently required on-site, via telehealth, or through community partners include acupuncture and battlefield acupuncture (battlefield auricular acupuncture), biofeedback, clinical hypnosis, guided imagery, medical massage therapy, medication, tai chi/qigong, and yoga. Optional approaches, which may be made available to veterans, include chiropractic and healing touch. Outside the VHA, some states have introduced or enacted legislation mandating insurance coverage of nonpharmacological pain treatments.¹⁸ However, these requirements and mandates do not help address challenges such as the availability of trained/qualified practitioners.^19,20 Ensuring access to complementary and integrative health treatments requires a more concerted effort to ensure that supply meets demand. It is also important to acknowledge the budgetary and physical space constraints that further limit access to services. Although expansion and integration of integrative medicine services remain a priority within the VA Whole Health program, implementation is contingent on available financial and infrastructure resources.

Time was also identified by PCPs as a barrier to recommending integrative therapies to patients. Developing and implementing time-efficient communication strategies for patient education such as concise talking points and informational handouts could help address this barrier. Furthermore, leveraging existing programs and engaging the entire health care team in patient education and referral could help increase integrative and complementary therapy uptake and use.

Although access and time were identified as major barriers, these findings also suggest that PCP and patient knowledge are another target area for enhancing the use of complementary and integrative therapies. Like prior research, most clinicians identified a lack of familiarity with certain services and a lack of scientific evidence as extremely or somewhat likely to affect their ability to offer integrative services to patients with chronic pain.²¹ Likewise, about 40% of patients identified being unfamiliar with a specific therapy as one of the major obstacles to receiving integrative therapies, with a similar number identifying PCPs as a source of information. The lack of familiarity may be due in part to the evolving nomenclature, with terms such as alternative, complementary, and integrative used to describe approaches outside what is often considered conventional medicine.¹⁰ On the other hand, there has also been considerable expansion in the number of therapies within this domain, along with an expanding evidence base. This suggests a need for targeted educational strategies for clinicians and patients, which can be rapidly deployed and continuously adapted as new therapies and evidence emerge.

Limitations

There are some inherent limitations with a survey-based approach, including sampling, non-response, and social desirability biases. In addition, this study only included PCPs and patients affiliated with a single VA medical center. Steps to mitigate these limitations included maintaining survey anonymity and reporting information about respondent characteristics to enhance transparency about the representativeness of the study findings.

CONCLUSIONS

Expanding the use of nonpharmacological pain treatments, including integrative modalities, is essential for safe and effective chronic pain management and reducing opioid use. Our findings show that VA PCPs and patients with chronic back pain are interested in and have some experience with certain integrative therapies. However, even within the context of a health care system that supports the use of integrative therapies for chronic pain as part of whole person care, increasing uptake will require addressing access and time-related constraints as well as ongoing clinician and patient education.

Total hip arthroplasty (THA) is among the most common elective orthopedic procedures performed annually in the United States, with an estimated 635,000 to 909,000 THAs expected each year by 2030.¹ Consequently, complication rates and revision surgeries related to THA have been increasing, along with the financial burden on the health care system.^2-4 Optimizing outcomes for patients undergoing THA and identifying risk factors for treatment failure have become areas of focus.

Over the last decade, there has been a renewed interest in the effect of previous lumbar spine fusion (LSF) surgery on THA outcomes. Studies have explored the rates of complications, postoperative mobility, and THA implant impingement.^5-8 However, the outcome receiving the most attention in recent literature is the rate and effect of dislocation in patients with lumbar fusion surgery. Large Medicare database analyses have discovered an association with increased rates of dislocations in patients with lumbar fusion surgeries compared with those without.^9,10 Prosthetic hip dislocation is an expensive complication of THA and is projected to have greater impact through 2035 due to a growing number of THA procedures.¹¹ Identifying risk factors associated with hip dislocation is paramount to mitigating its effect on patients who have undergone THA.

Recent research has found increased rates of THA dislocation and revision surgery in patients with LSF, with some studies showing previous LSF as the strongest independent predictor.^6-16 However, controversy surrounds this relationship, including the sequence of procedures (LSF before or after THA), the time between procedures, and involvement of the sacrum in LSF. One study found that patients had a 106% increased risk of dislocation when LSF was performed before THA compared with patients who underwent LSF 5 years after undergoing THA, while another study showed no significant difference in dislocations pre- vs post-LSF.^16,17 An additional study showed no significant difference in the rate of dislocation in patients without sacral involvement in the LSF, while also showing significantly higher rates of dislocation in LSF with sacral involvement.¹² The researchers also found a trend toward more dislocations in longer lumbosacral fusions. Recent studies have also examined dislocation rates with lumbar fusion in patients treated with dual-mobility liners.^18-20 The consensus from these studies is that dual-mobility liners significantly decrease the rate of dislocation in primary THAs with lumbar fusion.

The present study sought to determine the rates of hip dislocations in a US Department of Veterans Affairs (VA) hospital setting. To the authors’ knowledge, no retrospective study focusing on THAs in the veteran population has been performed. This study benefits from controlling for various surgeon techniques and surgical preferences when compared to large Medicare database studies because the orthopedic surgeon (ABK) only performed the posterior approach for all patients during the study period.

The primary objective of this study was to determine whether the rates of hip dislocation would, in fact, be higher in patients with lumbar fusion surgery, as recent database studies suggest. Secondary objectives included determining whether patient characteristics, comorbidities, number of levels fused, or inclusion of the sacrum in the fusion construct influenced dislocation rates. Furthermore, VA Dayton Healthcare System (VADHS) began routine use of dual-mobility liners for lumbar fusion patients in 2018, allowing for examination of these patients.

Methods

The Wright State University and VADHS Institutional Review Board approved this study design. A retrospective review of all primary THAs at VADHS was performed to investigate the relationship between previous lumbar spine fusion and the incidence of THA revision. Manual chart review was performed for patients who underwent primary THA between January 2003, and December 2022. One surgeon performed all surgeries using only the posterior approach. Patients were not excluded if they had bilateral procedures and all eligible hips were included. Patients with a concomitant diagnosis of fracture of the femoral head or femoral neck at the time of surgery were excluded. Additionally, only patients with ≥ 12 months of follow-up data were included.

The primary outcome was dislocation within 12 months of THA; the primary independent variable was LSF prior to THA. Covariates included patient demographics (age, sex, body mass index [BMI]) and Charlson Comorbidity Index (CCI) score, with additional data collected on the number of levels fused, sacral spine involvement, revision rates, and use of dual-mobility liners. Year of surgery was also included in analyses to account for any changes that may have occurred during the study period.

Statistical Analysis

Statistical analyses were performed in SAS 9.4. Patients were grouped into 2 cohorts, depending on whether they had received LSF prior to THA. Analyses were adjusted for repeated measures to account for the small percentage of patients with bilateral procedures.

Univariate comparisons between cohorts for covariates, as well as rates of dislocation and revision, were performed using the independent samples t test for continuous variables and the Fisher exact test for dichotomous categorical variables. Significant comorbidities, as well as age, sex, BMI, liner type, LSF cohort, and surgery year, were included in a logistic regression model to determine what effect, if any, they had on the likelihood of dislocation. Variables were removed using a backward stepwise approach, starting with the nonsignificant variable effect with the lowest χ² value, and continuing until reaching a final model where all remaining variable effects were significant. For the variables retained in the final model, odds ratios (ORs) with 95% CIs were derived, with dislocation designated as the event. Individual comorbidity subcomponents of the CCI were also analyzed for their effects on dislocation using backward stepwise logistic regression. A secondary analysis among patients with LSF tested for the influence of the number of vertebral levels fused, the presence or absence of sacral involvement in the fusion, and the use of dual-mobility liners on the likelihood of hip dislocation.

Results

The LSF cohort included 39 patients with THA and prior LSF, 3 of whom had bilateral procedures, for a total of 42 hips. The non-LSF cohort included 813 patients with THA, 112 of whom had bilateral procedures, for a total of 925 hips. The LSF and non-LSF cohorts did not differ significantly in age, sex, BMI, CCI, or revision rates (Table). The LSF cohort included a significantly higher percentage of hips receiving dual-mobility liners than did the non-LSF cohort (23.8% vs 0.6%; P < .001) and had more than twice the rate of dislocation (4 of 42 hips [9.5%] vs 35 of 925 hips [3.8%]), although this difference was not statistically significant (P = .08).

The final logistic regression model with dislocation as the outcome was statistically significant (χ², 17.47; P < .001) and retained 2 significant predictor variables: LSF cohort (χ², 4.63; P = .03), and sex (χ², 18.27; P < .001). Females were more likely than males to experience dislocation (OR, 5.84; 95% CI, 2.60-13.13; P < .001) as were patients who had LSF prior to THA (OR, 3.42; 95% CI, 1.12-10.47; P = .03) (Figure). None of the CCI subcomponent comorbidities significantly affected the probability of dislocation (myocardial infarction, P = .46; congestive heart failure, P = .47; peripheral vascular disease, P = .97; stroke, P = .51; dementia, P = .99; chronic obstructive pulmonary disease, P = .95; connective tissue disease, P = .25; peptic ulcer, P = .41; liver disease, P = .30; diabetes, P = .06; hemiplegia, P = .99; chronic kidney disease, P = .82; solid tumor, P = .90; leukemia, P = .99; lymphoma, P = .99; AIDS, P = .99). Within the LSF cohort, neither the number of levels fused (P = .83) nor sacral involvement (P = .42), significantly affected the probability of hip dislocation. None of the patients in either cohort who received dual-mobility liners subsequently dislocated their hips, nor did any of them require revision surgery.

Discussion

Spinopelvic biomechanics have been an area of increasing interest and research. Spinal fusion has been shown to alter the mobility of the pelvis and has been associated with decreased stability of THA implants.²¹ For example, in the setting of a fused spine, the lack of compensatory changes in pelvic tilt or acetabular anteversion when adjusting to a seated or standing position may predispose patients to impingement because the acetabular component is not properly positioned. Dual-mobility constructs mitigate this risk by providing an additional articulation, which increases jump distance and range of motion prior to impingement, thereby enhancing stability.

The use of dual-mobility liners in patients with LSF has also been examined.^18-20 These studies demonstrate a reduced risk of postoperative THA dislocation in patients with previous LSF. The rate of postoperative complications and revisions for LSF patients with dual-mobility liners was also found to be similar to that of THAs without dual-mobility in patients without prior LSF. This study focused on a veteran population to demonstrate the efficacy of dual-mobility liners in patients with LSF. The results indicate that LSF prior to THA and female sex were predictors for prosthetic hip dislocations in the 12-month postoperative period in this patient population, which aligns with the current literature.

The dislocation rate in the LSF-THA group (9.5%) was higher than the dislocation rate in the control group (3.8%). Although not statistically significant in the univariate analysis, LSF was shown to be a significant risk factor after controlling for patient sex. Other studies have found the dislocation rate to be 3% to 7%, which is lower than the dislocation rate observed in this study.^8,10,16

The reasons for this higher rate of dislocation are not entirely clear. A veteran population has poorer overall health than the general population, which may contribute to the higher than previously reported dislocation rates.²² These results can be applied to the management of veterans seeking THA.

There have been conflicting reports regarding the impact a patient’s sex has on THA outcomes in the general population.^23-26 This study found that female patients had higher rates of dislocation within 1 year of THA than male patients. This difference, which could be due to differences in baseline anatomic hip morphology between the sexes; females tend to have smaller femoral head sizes and less offset compared with males.^27,28 However, this finding could have been confounded by the small number of female veterans in the study cohort.

A type 2 diabetes mellitus (T2DM) diagnosis, which is a component of CCI, trended toward increased risk of prosthetic hip dislocation. Multiple studies have also discussed the increased risk of postoperative infections and revisions following THA in patients with T2DM.^29-31 One study found T2DM to be an independent risk factor for immediate in-hospital postoperative complications following hip arthroplasty.³²

Another factor that may influence postoperative dislocation risk is surgical approach. The posterior approach has historically been associated with higher rates of instability when compared to anterior or lateral THA.³³ Researchers have also looked at the role that surgical approach plays in patients with prior LSF. Huebschmann et al confirmed that not only is LSF a significant risk factor for dislocation following THA, but anterior and laterally based surgical approaches may mitigate this risk.³⁴

Limitations

As a retrospective cohort study, the reliability of the data hinges on complete documentation. Documentation of all encounters for dislocations was obtained from the VA Computerized Patient Record System, which may have led to some dislocation events being missed. However, as long as there was adequate postoperative follow-up, it was assumed all events outside the VA were included. Another limitation of this study was that male patients greatly outnumbered female patients, and this fact could limit the generalizability of findings to the population as a whole.

Conclusions

This study in a veteran population found that prior LSF and female sex were significant predictors for postoperative dislocation within 1 year of THA surgery. Additionally, the use of a dual-mobility liner was found to be protective against postoperative dislocation events. These data allow clinicians to better counsel veterans on the risk factors associated with postoperative dislocation and strategies to mitigate this risk.

Total hip arthroplasty (THA) is among the most common elective orthopedic procedures performed annually in the United States, with an estimated 635,000 to 909,000 THAs expected each year by 2030.¹ Consequently, complication rates and revision surgeries related to THA have been increasing, along with the financial burden on the health care system.^2-4 Optimizing outcomes for patients undergoing THA and identifying risk factors for treatment failure have become areas of focus.

Over the last decade, there has been a renewed interest in the effect of previous lumbar spine fusion (LSF) surgery on THA outcomes. Studies have explored the rates of complications, postoperative mobility, and THA implant impingement.^5-8 However, the outcome receiving the most attention in recent literature is the rate and effect of dislocation in patients with lumbar fusion surgery. Large Medicare database analyses have discovered an association with increased rates of dislocations in patients with lumbar fusion surgeries compared with those without.^9,10 Prosthetic hip dislocation is an expensive complication of THA and is projected to have greater impact through 2035 due to a growing number of THA procedures.¹¹ Identifying risk factors associated with hip dislocation is paramount to mitigating its effect on patients who have undergone THA.

Recent research has found increased rates of THA dislocation and revision surgery in patients with LSF, with some studies showing previous LSF as the strongest independent predictor.^6-16 However, controversy surrounds this relationship, including the sequence of procedures (LSF before or after THA), the time between procedures, and involvement of the sacrum in LSF. One study found that patients had a 106% increased risk of dislocation when LSF was performed before THA compared with patients who underwent LSF 5 years after undergoing THA, while another study showed no significant difference in dislocations pre- vs post-LSF.^16,17 An additional study showed no significant difference in the rate of dislocation in patients without sacral involvement in the LSF, while also showing significantly higher rates of dislocation in LSF with sacral involvement.¹² The researchers also found a trend toward more dislocations in longer lumbosacral fusions. Recent studies have also examined dislocation rates with lumbar fusion in patients treated with dual-mobility liners.^18-20 The consensus from these studies is that dual-mobility liners significantly decrease the rate of dislocation in primary THAs with lumbar fusion.

The present study sought to determine the rates of hip dislocations in a US Department of Veterans Affairs (VA) hospital setting. To the authors’ knowledge, no retrospective study focusing on THAs in the veteran population has been performed. This study benefits from controlling for various surgeon techniques and surgical preferences when compared to large Medicare database studies because the orthopedic surgeon (ABK) only performed the posterior approach for all patients during the study period.

The primary objective of this study was to determine whether the rates of hip dislocation would, in fact, be higher in patients with lumbar fusion surgery, as recent database studies suggest. Secondary objectives included determining whether patient characteristics, comorbidities, number of levels fused, or inclusion of the sacrum in the fusion construct influenced dislocation rates. Furthermore, VA Dayton Healthcare System (VADHS) began routine use of dual-mobility liners for lumbar fusion patients in 2018, allowing for examination of these patients.

Methods

The Wright State University and VADHS Institutional Review Board approved this study design. A retrospective review of all primary THAs at VADHS was performed to investigate the relationship between previous lumbar spine fusion and the incidence of THA revision. Manual chart review was performed for patients who underwent primary THA between January 2003, and December 2022. One surgeon performed all surgeries using only the posterior approach. Patients were not excluded if they had bilateral procedures and all eligible hips were included. Patients with a concomitant diagnosis of fracture of the femoral head or femoral neck at the time of surgery were excluded. Additionally, only patients with ≥ 12 months of follow-up data were included.

The primary outcome was dislocation within 12 months of THA; the primary independent variable was LSF prior to THA. Covariates included patient demographics (age, sex, body mass index [BMI]) and Charlson Comorbidity Index (CCI) score, with additional data collected on the number of levels fused, sacral spine involvement, revision rates, and use of dual-mobility liners. Year of surgery was also included in analyses to account for any changes that may have occurred during the study period.

Statistical Analysis

Statistical analyses were performed in SAS 9.4. Patients were grouped into 2 cohorts, depending on whether they had received LSF prior to THA. Analyses were adjusted for repeated measures to account for the small percentage of patients with bilateral procedures.

Univariate comparisons between cohorts for covariates, as well as rates of dislocation and revision, were performed using the independent samples t test for continuous variables and the Fisher exact test for dichotomous categorical variables. Significant comorbidities, as well as age, sex, BMI, liner type, LSF cohort, and surgery year, were included in a logistic regression model to determine what effect, if any, they had on the likelihood of dislocation. Variables were removed using a backward stepwise approach, starting with the nonsignificant variable effect with the lowest χ² value, and continuing until reaching a final model where all remaining variable effects were significant. For the variables retained in the final model, odds ratios (ORs) with 95% CIs were derived, with dislocation designated as the event. Individual comorbidity subcomponents of the CCI were also analyzed for their effects on dislocation using backward stepwise logistic regression. A secondary analysis among patients with LSF tested for the influence of the number of vertebral levels fused, the presence or absence of sacral involvement in the fusion, and the use of dual-mobility liners on the likelihood of hip dislocation.

Results

The LSF cohort included 39 patients with THA and prior LSF, 3 of whom had bilateral procedures, for a total of 42 hips. The non-LSF cohort included 813 patients with THA, 112 of whom had bilateral procedures, for a total of 925 hips. The LSF and non-LSF cohorts did not differ significantly in age, sex, BMI, CCI, or revision rates (Table). The LSF cohort included a significantly higher percentage of hips receiving dual-mobility liners than did the non-LSF cohort (23.8% vs 0.6%; P < .001) and had more than twice the rate of dislocation (4 of 42 hips [9.5%] vs 35 of 925 hips [3.8%]), although this difference was not statistically significant (P = .08).

The final logistic regression model with dislocation as the outcome was statistically significant (χ², 17.47; P < .001) and retained 2 significant predictor variables: LSF cohort (χ², 4.63; P = .03), and sex (χ², 18.27; P < .001). Females were more likely than males to experience dislocation (OR, 5.84; 95% CI, 2.60-13.13; P < .001) as were patients who had LSF prior to THA (OR, 3.42; 95% CI, 1.12-10.47; P = .03) (Figure). None of the CCI subcomponent comorbidities significantly affected the probability of dislocation (myocardial infarction, P = .46; congestive heart failure, P = .47; peripheral vascular disease, P = .97; stroke, P = .51; dementia, P = .99; chronic obstructive pulmonary disease, P = .95; connective tissue disease, P = .25; peptic ulcer, P = .41; liver disease, P = .30; diabetes, P = .06; hemiplegia, P = .99; chronic kidney disease, P = .82; solid tumor, P = .90; leukemia, P = .99; lymphoma, P = .99; AIDS, P = .99). Within the LSF cohort, neither the number of levels fused (P = .83) nor sacral involvement (P = .42), significantly affected the probability of hip dislocation. None of the patients in either cohort who received dual-mobility liners subsequently dislocated their hips, nor did any of them require revision surgery.

Discussion

Spinopelvic biomechanics have been an area of increasing interest and research. Spinal fusion has been shown to alter the mobility of the pelvis and has been associated with decreased stability of THA implants.²¹ For example, in the setting of a fused spine, the lack of compensatory changes in pelvic tilt or acetabular anteversion when adjusting to a seated or standing position may predispose patients to impingement because the acetabular component is not properly positioned. Dual-mobility constructs mitigate this risk by providing an additional articulation, which increases jump distance and range of motion prior to impingement, thereby enhancing stability.

The use of dual-mobility liners in patients with LSF has also been examined.^18-20 These studies demonstrate a reduced risk of postoperative THA dislocation in patients with previous LSF. The rate of postoperative complications and revisions for LSF patients with dual-mobility liners was also found to be similar to that of THAs without dual-mobility in patients without prior LSF. This study focused on a veteran population to demonstrate the efficacy of dual-mobility liners in patients with LSF. The results indicate that LSF prior to THA and female sex were predictors for prosthetic hip dislocations in the 12-month postoperative period in this patient population, which aligns with the current literature.

The dislocation rate in the LSF-THA group (9.5%) was higher than the dislocation rate in the control group (3.8%). Although not statistically significant in the univariate analysis, LSF was shown to be a significant risk factor after controlling for patient sex. Other studies have found the dislocation rate to be 3% to 7%, which is lower than the dislocation rate observed in this study.^8,10,16

The reasons for this higher rate of dislocation are not entirely clear. A veteran population has poorer overall health than the general population, which may contribute to the higher than previously reported dislocation rates.²² These results can be applied to the management of veterans seeking THA.

There have been conflicting reports regarding the impact a patient’s sex has on THA outcomes in the general population.^23-26 This study found that female patients had higher rates of dislocation within 1 year of THA than male patients. This difference, which could be due to differences in baseline anatomic hip morphology between the sexes; females tend to have smaller femoral head sizes and less offset compared with males.^27,28 However, this finding could have been confounded by the small number of female veterans in the study cohort.

A type 2 diabetes mellitus (T2DM) diagnosis, which is a component of CCI, trended toward increased risk of prosthetic hip dislocation. Multiple studies have also discussed the increased risk of postoperative infections and revisions following THA in patients with T2DM.^29-31 One study found T2DM to be an independent risk factor for immediate in-hospital postoperative complications following hip arthroplasty.³²

Another factor that may influence postoperative dislocation risk is surgical approach. The posterior approach has historically been associated with higher rates of instability when compared to anterior or lateral THA.³³ Researchers have also looked at the role that surgical approach plays in patients with prior LSF. Huebschmann et al confirmed that not only is LSF a significant risk factor for dislocation following THA, but anterior and laterally based surgical approaches may mitigate this risk.³⁴

Limitations

As a retrospective cohort study, the reliability of the data hinges on complete documentation. Documentation of all encounters for dislocations was obtained from the VA Computerized Patient Record System, which may have led to some dislocation events being missed. However, as long as there was adequate postoperative follow-up, it was assumed all events outside the VA were included. Another limitation of this study was that male patients greatly outnumbered female patients, and this fact could limit the generalizability of findings to the population as a whole.

Conclusions

This study in a veteran population found that prior LSF and female sex were significant predictors for postoperative dislocation within 1 year of THA surgery. Additionally, the use of a dual-mobility liner was found to be protective against postoperative dislocation events. These data allow clinicians to better counsel veterans on the risk factors associated with postoperative dislocation and strategies to mitigate this risk.

Total hip arthroplasty (THA) is among the most common elective orthopedic procedures performed annually in the United States, with an estimated 635,000 to 909,000 THAs expected each year by 2030.¹ Consequently, complication rates and revision surgeries related to THA have been increasing, along with the financial burden on the health care system.^2-4 Optimizing outcomes for patients undergoing THA and identifying risk factors for treatment failure have become areas of focus.

Over the last decade, there has been a renewed interest in the effect of previous lumbar spine fusion (LSF) surgery on THA outcomes. Studies have explored the rates of complications, postoperative mobility, and THA implant impingement.^5-8 However, the outcome receiving the most attention in recent literature is the rate and effect of dislocation in patients with lumbar fusion surgery. Large Medicare database analyses have discovered an association with increased rates of dislocations in patients with lumbar fusion surgeries compared with those without.^9,10 Prosthetic hip dislocation is an expensive complication of THA and is projected to have greater impact through 2035 due to a growing number of THA procedures.¹¹ Identifying risk factors associated with hip dislocation is paramount to mitigating its effect on patients who have undergone THA.

Recent research has found increased rates of THA dislocation and revision surgery in patients with LSF, with some studies showing previous LSF as the strongest independent predictor.^6-16 However, controversy surrounds this relationship, including the sequence of procedures (LSF before or after THA), the time between procedures, and involvement of the sacrum in LSF. One study found that patients had a 106% increased risk of dislocation when LSF was performed before THA compared with patients who underwent LSF 5 years after undergoing THA, while another study showed no significant difference in dislocations pre- vs post-LSF.^16,17 An additional study showed no significant difference in the rate of dislocation in patients without sacral involvement in the LSF, while also showing significantly higher rates of dislocation in LSF with sacral involvement.¹² The researchers also found a trend toward more dislocations in longer lumbosacral fusions. Recent studies have also examined dislocation rates with lumbar fusion in patients treated with dual-mobility liners.^18-20 The consensus from these studies is that dual-mobility liners significantly decrease the rate of dislocation in primary THAs with lumbar fusion.

The present study sought to determine the rates of hip dislocations in a US Department of Veterans Affairs (VA) hospital setting. To the authors’ knowledge, no retrospective study focusing on THAs in the veteran population has been performed. This study benefits from controlling for various surgeon techniques and surgical preferences when compared to large Medicare database studies because the orthopedic surgeon (ABK) only performed the posterior approach for all patients during the study period.

The primary objective of this study was to determine whether the rates of hip dislocation would, in fact, be higher in patients with lumbar fusion surgery, as recent database studies suggest. Secondary objectives included determining whether patient characteristics, comorbidities, number of levels fused, or inclusion of the sacrum in the fusion construct influenced dislocation rates. Furthermore, VA Dayton Healthcare System (VADHS) began routine use of dual-mobility liners for lumbar fusion patients in 2018, allowing for examination of these patients.

Methods

The Wright State University and VADHS Institutional Review Board approved this study design. A retrospective review of all primary THAs at VADHS was performed to investigate the relationship between previous lumbar spine fusion and the incidence of THA revision. Manual chart review was performed for patients who underwent primary THA between January 2003, and December 2022. One surgeon performed all surgeries using only the posterior approach. Patients were not excluded if they had bilateral procedures and all eligible hips were included. Patients with a concomitant diagnosis of fracture of the femoral head or femoral neck at the time of surgery were excluded. Additionally, only patients with ≥ 12 months of follow-up data were included.

The primary outcome was dislocation within 12 months of THA; the primary independent variable was LSF prior to THA. Covariates included patient demographics (age, sex, body mass index [BMI]) and Charlson Comorbidity Index (CCI) score, with additional data collected on the number of levels fused, sacral spine involvement, revision rates, and use of dual-mobility liners. Year of surgery was also included in analyses to account for any changes that may have occurred during the study period.

Statistical Analysis

Statistical analyses were performed in SAS 9.4. Patients were grouped into 2 cohorts, depending on whether they had received LSF prior to THA. Analyses were adjusted for repeated measures to account for the small percentage of patients with bilateral procedures.

Univariate comparisons between cohorts for covariates, as well as rates of dislocation and revision, were performed using the independent samples t test for continuous variables and the Fisher exact test for dichotomous categorical variables. Significant comorbidities, as well as age, sex, BMI, liner type, LSF cohort, and surgery year, were included in a logistic regression model to determine what effect, if any, they had on the likelihood of dislocation. Variables were removed using a backward stepwise approach, starting with the nonsignificant variable effect with the lowest χ² value, and continuing until reaching a final model where all remaining variable effects were significant. For the variables retained in the final model, odds ratios (ORs) with 95% CIs were derived, with dislocation designated as the event. Individual comorbidity subcomponents of the CCI were also analyzed for their effects on dislocation using backward stepwise logistic regression. A secondary analysis among patients with LSF tested for the influence of the number of vertebral levels fused, the presence or absence of sacral involvement in the fusion, and the use of dual-mobility liners on the likelihood of hip dislocation.

Results

The LSF cohort included 39 patients with THA and prior LSF, 3 of whom had bilateral procedures, for a total of 42 hips. The non-LSF cohort included 813 patients with THA, 112 of whom had bilateral procedures, for a total of 925 hips. The LSF and non-LSF cohorts did not differ significantly in age, sex, BMI, CCI, or revision rates (Table). The LSF cohort included a significantly higher percentage of hips receiving dual-mobility liners than did the non-LSF cohort (23.8% vs 0.6%; P < .001) and had more than twice the rate of dislocation (4 of 42 hips [9.5%] vs 35 of 925 hips [3.8%]), although this difference was not statistically significant (P = .08).

The final logistic regression model with dislocation as the outcome was statistically significant (χ², 17.47; P < .001) and retained 2 significant predictor variables: LSF cohort (χ², 4.63; P = .03), and sex (χ², 18.27; P < .001). Females were more likely than males to experience dislocation (OR, 5.84; 95% CI, 2.60-13.13; P < .001) as were patients who had LSF prior to THA (OR, 3.42; 95% CI, 1.12-10.47; P = .03) (Figure). None of the CCI subcomponent comorbidities significantly affected the probability of dislocation (myocardial infarction, P = .46; congestive heart failure, P = .47; peripheral vascular disease, P = .97; stroke, P = .51; dementia, P = .99; chronic obstructive pulmonary disease, P = .95; connective tissue disease, P = .25; peptic ulcer, P = .41; liver disease, P = .30; diabetes, P = .06; hemiplegia, P = .99; chronic kidney disease, P = .82; solid tumor, P = .90; leukemia, P = .99; lymphoma, P = .99; AIDS, P = .99). Within the LSF cohort, neither the number of levels fused (P = .83) nor sacral involvement (P = .42), significantly affected the probability of hip dislocation. None of the patients in either cohort who received dual-mobility liners subsequently dislocated their hips, nor did any of them require revision surgery.

Discussion

Spinopelvic biomechanics have been an area of increasing interest and research. Spinal fusion has been shown to alter the mobility of the pelvis and has been associated with decreased stability of THA implants.²¹ For example, in the setting of a fused spine, the lack of compensatory changes in pelvic tilt or acetabular anteversion when adjusting to a seated or standing position may predispose patients to impingement because the acetabular component is not properly positioned. Dual-mobility constructs mitigate this risk by providing an additional articulation, which increases jump distance and range of motion prior to impingement, thereby enhancing stability.

The use of dual-mobility liners in patients with LSF has also been examined.^18-20 These studies demonstrate a reduced risk of postoperative THA dislocation in patients with previous LSF. The rate of postoperative complications and revisions for LSF patients with dual-mobility liners was also found to be similar to that of THAs without dual-mobility in patients without prior LSF. This study focused on a veteran population to demonstrate the efficacy of dual-mobility liners in patients with LSF. The results indicate that LSF prior to THA and female sex were predictors for prosthetic hip dislocations in the 12-month postoperative period in this patient population, which aligns with the current literature.

The dislocation rate in the LSF-THA group (9.5%) was higher than the dislocation rate in the control group (3.8%). Although not statistically significant in the univariate analysis, LSF was shown to be a significant risk factor after controlling for patient sex. Other studies have found the dislocation rate to be 3% to 7%, which is lower than the dislocation rate observed in this study.^8,10,16

The reasons for this higher rate of dislocation are not entirely clear. A veteran population has poorer overall health than the general population, which may contribute to the higher than previously reported dislocation rates.²² These results can be applied to the management of veterans seeking THA.

There have been conflicting reports regarding the impact a patient’s sex has on THA outcomes in the general population.^23-26 This study found that female patients had higher rates of dislocation within 1 year of THA than male patients. This difference, which could be due to differences in baseline anatomic hip morphology between the sexes; females tend to have smaller femoral head sizes and less offset compared with males.^27,28 However, this finding could have been confounded by the small number of female veterans in the study cohort.

A type 2 diabetes mellitus (T2DM) diagnosis, which is a component of CCI, trended toward increased risk of prosthetic hip dislocation. Multiple studies have also discussed the increased risk of postoperative infections and revisions following THA in patients with T2DM.^29-31 One study found T2DM to be an independent risk factor for immediate in-hospital postoperative complications following hip arthroplasty.³²

Another factor that may influence postoperative dislocation risk is surgical approach. The posterior approach has historically been associated with higher rates of instability when compared to anterior or lateral THA.³³ Researchers have also looked at the role that surgical approach plays in patients with prior LSF. Huebschmann et al confirmed that not only is LSF a significant risk factor for dislocation following THA, but anterior and laterally based surgical approaches may mitigate this risk.³⁴

Limitations

As a retrospective cohort study, the reliability of the data hinges on complete documentation. Documentation of all encounters for dislocations was obtained from the VA Computerized Patient Record System, which may have led to some dislocation events being missed. However, as long as there was adequate postoperative follow-up, it was assumed all events outside the VA were included. Another limitation of this study was that male patients greatly outnumbered female patients, and this fact could limit the generalizability of findings to the population as a whole.

Conclusions

This study in a veteran population found that prior LSF and female sex were significant predictors for postoperative dislocation within 1 year of THA surgery. Additionally, the use of a dual-mobility liner was found to be protective against postoperative dislocation events. These data allow clinicians to better counsel veterans on the risk factors associated with postoperative dislocation and strategies to mitigate this risk.

Discussion

A diagnosis of dural arteriovenous fistula (dAVF) was made. Lesions involving the spinal cord are traditionally classified by location as extradural, intradural/extramedullary, or intramedullary. Intramedullary spinal cord abnormalities pose considerable diagnostic and management challenges because of the risks of biopsy in this location and the added potential for morbidity and mortality from improperly treated lesions. Although MRI is the preferred imaging modality, PET/CT and magnetic resonance angiography (MRA) may also help narrow the differential diagnosis and potentially avoid complications from an invasive biopsy.¹ This patient’s intramedullary lesion, which represented a dAVF, posed a diagnostic challenge; after diagnosis, it was successfully managed conservatively with dexamethasone and physical therapy.

Intradural tumors account for 2% to 4% of all primary central nervous system (CNS) tumors.² Ependymomas account for 50% to 60% of intramedullary tumors in adults, while astrocytomas account for about 60% of all lesions in children and adolescents.^3,4 The differential diagnosis for intramedullary tumors also includes hemangioblastoma, metastases, primary CNS lymphoma, germ cell tumors, and gangliogliomas.^5,6

Intramedullary metastases remain rare, although the incidence is rising with improvements in oncologic and supportive treatments. Autopsy studies conducted decades ago demonstrated that about 0.9% to 2.1% of patients with systemic cancer have intramedullary metastases at death.^7,8 In patients with an established history of malignancy, a metastatic intramedullary tumor should be placed higher on the differential diagnosis. Intramedullary metastases most often occur in the setting of widespread metastatic disease. A systematic review of the literature on patients with lung cancer (small cell and non-small cell lung carcinomas) and ≥ 1 intramedullary spinal cord metastasis demonstrated that 55.8% of patients had concurrent brain metastases, 20.0% had leptomeningeal carcinomatosis, and 19.5% had vertebral metastases.⁹ While about half of all intramedullary metastases are associated with lung cancer, other common malignancies that metastasize to this area include colorectal, breast, and renal cell carcinoma, as well as lymphoma and melanoma primaries.^10,11

On imaging, intramedullary metastases often appear as several short, studded segments with surrounding edema, typically out of proportion to the size of the lesion.¹ By contrast, astrocytomas and ependymomas often span multiple segments, and enhancement patterns can vary depending on the subtype and grade. Glioblastoma multiforme, or grade 4 IDH wild-type astrocytomas, demonstrate an irregular, heterogeneous pattern of enhancement. Hemangioblastomas vary in size and are classically hypointense to isointense on T1-weighted sequences, isointense to hyperintense on T2-weighted sequences, and demonstrate avid enhancement on T1- postcontrast images. In large hemangioblastomas, flow voids due to prominent vasculature may be visualized.

Numerous nonneoplastic tumor mimics can obscure the differential diagnosis. Vascular malformations, including cavernomas and dAVFs, can also present with enhancement and edema. dAVFs are the most common type of spinal vascular malformation, accounting for about 70% of cases.¹² They are supplied by the radiculomeningeal arteries, whereas pial arteriovenous malformations (AVMs) are supplied by the radiculomedullary and radiculopial arteries. On MRI, dAVFs usually have venous congestion with intramedullary edema, which appears as an ill-defined centromedullary hyperintensity on T2-weighted imaging over multiple segments. The spinal cord may appear swollen with atrophic changes in chronic cases. Spinal cord AVMs are rarer and have an intramedullary nidus. They usually demonstrate mixed heterogeneous signal on T1- and T2-weighted imaging due to blood products, while the nidus demonstrates a variable degree of enhancement. Serpiginous flow voids are seen both within the nidus and at the cord surface.

Demyelinating lesions of the spine may be seen in neuroinflammatory conditions such as multiple sclerosis, neuromyelitis optica spectrum disorder, acute transverse myelitis, and acute disseminated encephalomyelitis. In multiple sclerosis, lesions typically extend ≤ 2 vertebral segments in length, cover less than half of the vertebral cross-sectional area, and have a dorsolateral predilection.¹³ Active lesions may demonstrate enhancement along the rim or in a patchy pattern. In the presence of demyelinating lesions, there may occasionally appear to be an expansile mass with a syrinx.¹⁴

Infections such as tuberculosis and neurosarcoidosis should also remain on the differential diagnosis. On MRI, tuberculosis usually involves the thoracic cord and is typically rim-enhancing.¹⁵ If there are caseating granulomas, T2-weighted images may also demonstrate rim enhancement.¹⁶ Spinal sarcoidosis is unusual without intracranial involvement, and its appearance may include leptomeningeal enhancement, cord expansion, and hyperintense signal on T2- weighted imaging.¹⁷

Finally, iatrogenic causes are also possible, including radiation myelopathy and mechanical spinal cord injury. For radiation myelopathy, it is important to ascertain whether a patient has undergone prior radiotherapy in the region and to obtain the pertinent dosimetry. Spinal cord injury may cause a focal signal abnormality within the cord, with T2 hyperintensity; these foci may or may not present with enhancement, edema, or hematoma and therefore may resemble tumors.¹³

This patient presented with progressive right-sided lower extremity weakness and hypoesthesia and a history of a low-grade right renal/pelvic ureteral tumor. The immediate impression was that the thoracic intramedullary lesion represented a metastatic lesion. However, in the absence of any systemic or intracranial metastases, this progression was much less likely. An extensive interdisciplinary workup was conducted that included medical oncology, neurology, neuroradiology, neuro-oncology, neurosurgery, nuclear medicine, and radiation oncology. Neuroradiology and nuclear medicine identified a slightly hypermetabolic focus on the PET/CT from 1.5 years prior that correlated exactly with the same location as the lesion on the recent spinal MRI. This finding, along with the MRA, confirmed the diagnosis of a dAVF, which was successfully managed conservatively with dexamethasone and physical therapy, rather than through oncologic treatments such as radiotherapy

There remains debate regarding the utility of steroids in treating patients with dAVF. Although there are some case reports documenting that the edema associated with the dAVF responds to steroids, other case series have found that steroids may worsen outcomes in patients with dAVF, possibly due to increased venous hydrostatic pressure.

This case demonstrates the importance of an interdisciplinary workup when evaluating an intramedullary lesion, as well as maintaining a wide differential diagnosis, particularly in the absence of a history of polymetastatic cancer. All the clues (such as the slightly hypermetabolic focus on a PET/CT from 1.5 years prior) need to be obtained to comfortably reach a diagnosis in the absence of pathologic confirmation. These cases can be especially challenging due to the lack of pathologic confirmation, but by understanding the main differentiating features among the various etiologies and obtaining all available information, a correct diagnosis can be made without unnecessary interventions.

Discussion

A diagnosis of dural arteriovenous fistula (dAVF) was made. Lesions involving the spinal cord are traditionally classified by location as extradural, intradural/extramedullary, or intramedullary. Intramedullary spinal cord abnormalities pose considerable diagnostic and management challenges because of the risks of biopsy in this location and the added potential for morbidity and mortality from improperly treated lesions. Although MRI is the preferred imaging modality, PET/CT and magnetic resonance angiography (MRA) may also help narrow the differential diagnosis and potentially avoid complications from an invasive biopsy.¹ This patient’s intramedullary lesion, which represented a dAVF, posed a diagnostic challenge; after diagnosis, it was successfully managed conservatively with dexamethasone and physical therapy.

Intradural tumors account for 2% to 4% of all primary central nervous system (CNS) tumors.² Ependymomas account for 50% to 60% of intramedullary tumors in adults, while astrocytomas account for about 60% of all lesions in children and adolescents.^3,4 The differential diagnosis for intramedullary tumors also includes hemangioblastoma, metastases, primary CNS lymphoma, germ cell tumors, and gangliogliomas.^5,6

Intramedullary metastases remain rare, although the incidence is rising with improvements in oncologic and supportive treatments. Autopsy studies conducted decades ago demonstrated that about 0.9% to 2.1% of patients with systemic cancer have intramedullary metastases at death.^7,8 In patients with an established history of malignancy, a metastatic intramedullary tumor should be placed higher on the differential diagnosis. Intramedullary metastases most often occur in the setting of widespread metastatic disease. A systematic review of the literature on patients with lung cancer (small cell and non-small cell lung carcinomas) and ≥ 1 intramedullary spinal cord metastasis demonstrated that 55.8% of patients had concurrent brain metastases, 20.0% had leptomeningeal carcinomatosis, and 19.5% had vertebral metastases.⁹ While about half of all intramedullary metastases are associated with lung cancer, other common malignancies that metastasize to this area include colorectal, breast, and renal cell carcinoma, as well as lymphoma and melanoma primaries.^10,11

On imaging, intramedullary metastases often appear as several short, studded segments with surrounding edema, typically out of proportion to the size of the lesion.¹ By contrast, astrocytomas and ependymomas often span multiple segments, and enhancement patterns can vary depending on the subtype and grade. Glioblastoma multiforme, or grade 4 IDH wild-type astrocytomas, demonstrate an irregular, heterogeneous pattern of enhancement. Hemangioblastomas vary in size and are classically hypointense to isointense on T1-weighted sequences, isointense to hyperintense on T2-weighted sequences, and demonstrate avid enhancement on T1- postcontrast images. In large hemangioblastomas, flow voids due to prominent vasculature may be visualized.

Numerous nonneoplastic tumor mimics can obscure the differential diagnosis. Vascular malformations, including cavernomas and dAVFs, can also present with enhancement and edema. dAVFs are the most common type of spinal vascular malformation, accounting for about 70% of cases.¹² They are supplied by the radiculomeningeal arteries, whereas pial arteriovenous malformations (AVMs) are supplied by the radiculomedullary and radiculopial arteries. On MRI, dAVFs usually have venous congestion with intramedullary edema, which appears as an ill-defined centromedullary hyperintensity on T2-weighted imaging over multiple segments. The spinal cord may appear swollen with atrophic changes in chronic cases. Spinal cord AVMs are rarer and have an intramedullary nidus. They usually demonstrate mixed heterogeneous signal on T1- and T2-weighted imaging due to blood products, while the nidus demonstrates a variable degree of enhancement. Serpiginous flow voids are seen both within the nidus and at the cord surface.

Demyelinating lesions of the spine may be seen in neuroinflammatory conditions such as multiple sclerosis, neuromyelitis optica spectrum disorder, acute transverse myelitis, and acute disseminated encephalomyelitis. In multiple sclerosis, lesions typically extend ≤ 2 vertebral segments in length, cover less than half of the vertebral cross-sectional area, and have a dorsolateral predilection.¹³ Active lesions may demonstrate enhancement along the rim or in a patchy pattern. In the presence of demyelinating lesions, there may occasionally appear to be an expansile mass with a syrinx.¹⁴

Infections such as tuberculosis and neurosarcoidosis should also remain on the differential diagnosis. On MRI, tuberculosis usually involves the thoracic cord and is typically rim-enhancing.¹⁵ If there are caseating granulomas, T2-weighted images may also demonstrate rim enhancement.¹⁶ Spinal sarcoidosis is unusual without intracranial involvement, and its appearance may include leptomeningeal enhancement, cord expansion, and hyperintense signal on T2- weighted imaging.¹⁷

Finally, iatrogenic causes are also possible, including radiation myelopathy and mechanical spinal cord injury. For radiation myelopathy, it is important to ascertain whether a patient has undergone prior radiotherapy in the region and to obtain the pertinent dosimetry. Spinal cord injury may cause a focal signal abnormality within the cord, with T2 hyperintensity; these foci may or may not present with enhancement, edema, or hematoma and therefore may resemble tumors.¹³

This patient presented with progressive right-sided lower extremity weakness and hypoesthesia and a history of a low-grade right renal/pelvic ureteral tumor. The immediate impression was that the thoracic intramedullary lesion represented a metastatic lesion. However, in the absence of any systemic or intracranial metastases, this progression was much less likely. An extensive interdisciplinary workup was conducted that included medical oncology, neurology, neuroradiology, neuro-oncology, neurosurgery, nuclear medicine, and radiation oncology. Neuroradiology and nuclear medicine identified a slightly hypermetabolic focus on the PET/CT from 1.5 years prior that correlated exactly with the same location as the lesion on the recent spinal MRI. This finding, along with the MRA, confirmed the diagnosis of a dAVF, which was successfully managed conservatively with dexamethasone and physical therapy, rather than through oncologic treatments such as radiotherapy

There remains debate regarding the utility of steroids in treating patients with dAVF. Although there are some case reports documenting that the edema associated with the dAVF responds to steroids, other case series have found that steroids may worsen outcomes in patients with dAVF, possibly due to increased venous hydrostatic pressure.

This case demonstrates the importance of an interdisciplinary workup when evaluating an intramedullary lesion, as well as maintaining a wide differential diagnosis, particularly in the absence of a history of polymetastatic cancer. All the clues (such as the slightly hypermetabolic focus on a PET/CT from 1.5 years prior) need to be obtained to comfortably reach a diagnosis in the absence of pathologic confirmation. These cases can be especially challenging due to the lack of pathologic confirmation, but by understanding the main differentiating features among the various etiologies and obtaining all available information, a correct diagnosis can be made without unnecessary interventions.

Discussion

A diagnosis of dural arteriovenous fistula (dAVF) was made. Lesions involving the spinal cord are traditionally classified by location as extradural, intradural/extramedullary, or intramedullary. Intramedullary spinal cord abnormalities pose considerable diagnostic and management challenges because of the risks of biopsy in this location and the added potential for morbidity and mortality from improperly treated lesions. Although MRI is the preferred imaging modality, PET/CT and magnetic resonance angiography (MRA) may also help narrow the differential diagnosis and potentially avoid complications from an invasive biopsy.¹ This patient’s intramedullary lesion, which represented a dAVF, posed a diagnostic challenge; after diagnosis, it was successfully managed conservatively with dexamethasone and physical therapy.

Intradural tumors account for 2% to 4% of all primary central nervous system (CNS) tumors.² Ependymomas account for 50% to 60% of intramedullary tumors in adults, while astrocytomas account for about 60% of all lesions in children and adolescents.^3,4 The differential diagnosis for intramedullary tumors also includes hemangioblastoma, metastases, primary CNS lymphoma, germ cell tumors, and gangliogliomas.^5,6

Intramedullary metastases remain rare, although the incidence is rising with improvements in oncologic and supportive treatments. Autopsy studies conducted decades ago demonstrated that about 0.9% to 2.1% of patients with systemic cancer have intramedullary metastases at death.^7,8 In patients with an established history of malignancy, a metastatic intramedullary tumor should be placed higher on the differential diagnosis. Intramedullary metastases most often occur in the setting of widespread metastatic disease. A systematic review of the literature on patients with lung cancer (small cell and non-small cell lung carcinomas) and ≥ 1 intramedullary spinal cord metastasis demonstrated that 55.8% of patients had concurrent brain metastases, 20.0% had leptomeningeal carcinomatosis, and 19.5% had vertebral metastases.⁹ While about half of all intramedullary metastases are associated with lung cancer, other common malignancies that metastasize to this area include colorectal, breast, and renal cell carcinoma, as well as lymphoma and melanoma primaries.^10,11

On imaging, intramedullary metastases often appear as several short, studded segments with surrounding edema, typically out of proportion to the size of the lesion.¹ By contrast, astrocytomas and ependymomas often span multiple segments, and enhancement patterns can vary depending on the subtype and grade. Glioblastoma multiforme, or grade 4 IDH wild-type astrocytomas, demonstrate an irregular, heterogeneous pattern of enhancement. Hemangioblastomas vary in size and are classically hypointense to isointense on T1-weighted sequences, isointense to hyperintense on T2-weighted sequences, and demonstrate avid enhancement on T1- postcontrast images. In large hemangioblastomas, flow voids due to prominent vasculature may be visualized.

Numerous nonneoplastic tumor mimics can obscure the differential diagnosis. Vascular malformations, including cavernomas and dAVFs, can also present with enhancement and edema. dAVFs are the most common type of spinal vascular malformation, accounting for about 70% of cases.¹² They are supplied by the radiculomeningeal arteries, whereas pial arteriovenous malformations (AVMs) are supplied by the radiculomedullary and radiculopial arteries. On MRI, dAVFs usually have venous congestion with intramedullary edema, which appears as an ill-defined centromedullary hyperintensity on T2-weighted imaging over multiple segments. The spinal cord may appear swollen with atrophic changes in chronic cases. Spinal cord AVMs are rarer and have an intramedullary nidus. They usually demonstrate mixed heterogeneous signal on T1- and T2-weighted imaging due to blood products, while the nidus demonstrates a variable degree of enhancement. Serpiginous flow voids are seen both within the nidus and at the cord surface.

Demyelinating lesions of the spine may be seen in neuroinflammatory conditions such as multiple sclerosis, neuromyelitis optica spectrum disorder, acute transverse myelitis, and acute disseminated encephalomyelitis. In multiple sclerosis, lesions typically extend ≤ 2 vertebral segments in length, cover less than half of the vertebral cross-sectional area, and have a dorsolateral predilection.¹³ Active lesions may demonstrate enhancement along the rim or in a patchy pattern. In the presence of demyelinating lesions, there may occasionally appear to be an expansile mass with a syrinx.¹⁴

Infections such as tuberculosis and neurosarcoidosis should also remain on the differential diagnosis. On MRI, tuberculosis usually involves the thoracic cord and is typically rim-enhancing.¹⁵ If there are caseating granulomas, T2-weighted images may also demonstrate rim enhancement.¹⁶ Spinal sarcoidosis is unusual without intracranial involvement, and its appearance may include leptomeningeal enhancement, cord expansion, and hyperintense signal on T2- weighted imaging.¹⁷

Finally, iatrogenic causes are also possible, including radiation myelopathy and mechanical spinal cord injury. For radiation myelopathy, it is important to ascertain whether a patient has undergone prior radiotherapy in the region and to obtain the pertinent dosimetry. Spinal cord injury may cause a focal signal abnormality within the cord, with T2 hyperintensity; these foci may or may not present with enhancement, edema, or hematoma and therefore may resemble tumors.¹³

This patient presented with progressive right-sided lower extremity weakness and hypoesthesia and a history of a low-grade right renal/pelvic ureteral tumor. The immediate impression was that the thoracic intramedullary lesion represented a metastatic lesion. However, in the absence of any systemic or intracranial metastases, this progression was much less likely. An extensive interdisciplinary workup was conducted that included medical oncology, neurology, neuroradiology, neuro-oncology, neurosurgery, nuclear medicine, and radiation oncology. Neuroradiology and nuclear medicine identified a slightly hypermetabolic focus on the PET/CT from 1.5 years prior that correlated exactly with the same location as the lesion on the recent spinal MRI. This finding, along with the MRA, confirmed the diagnosis of a dAVF, which was successfully managed conservatively with dexamethasone and physical therapy, rather than through oncologic treatments such as radiotherapy

There remains debate regarding the utility of steroids in treating patients with dAVF. Although there are some case reports documenting that the edema associated with the dAVF responds to steroids, other case series have found that steroids may worsen outcomes in patients with dAVF, possibly due to increased venous hydrostatic pressure.

This case demonstrates the importance of an interdisciplinary workup when evaluating an intramedullary lesion, as well as maintaining a wide differential diagnosis, particularly in the absence of a history of polymetastatic cancer. All the clues (such as the slightly hypermetabolic focus on a PET/CT from 1.5 years prior) need to be obtained to comfortably reach a diagnosis in the absence of pathologic confirmation. These cases can be especially challenging due to the lack of pathologic confirmation, but by understanding the main differentiating features among the various etiologies and obtaining all available information, a correct diagnosis can be made without unnecessary interventions.

Hyperkalemia involves elevated serum potassium levels (> 5.0 mEq/L) and represents an important electrolyte disturbance due to its potentially severe consequences, including cardiac effects that can lead to dysrhythmia and even asystole and death.^1,2 In a US Medicare population, the prevalence of hyperkalemia has been estimated at 2.7% and is associated with substantial health care costs.³ The prevalence is even more marked in patients with preexisting conditions such as chronic kidney disease (CKD) and heart failure.^4,5

Hyperkalemia can result from multiple factors, including impaired renal function, adrenal disease, adverse drug reactions of angiotensin-converting enzyme inhibitors (ACEIs) and other medications, and heritable mutations.⁶ Hyperkalemia poses a considerable clinical risk, associated with adverse outcomes such as myocardial infarction and increased mortality in patients with CKD.^5,7,8 Electrocardiographic (ECG) changes associated with hyperkalemia play a vital role in guiding clinical decisions and treatment strategies.⁹ Understanding the pathophysiology, risk factors, and consequences of hyperkalemia, as well as the significance of ECG changes in its management, is essential for health care practitioners.

Case Presentation

An 81-year-old Hispanic man with a history of hypertension, hypothyroidism, gout, and CKD stage 3B presented to the emergency department with progressive weakness resulting in falls and culminating in an inability to ambulate independently. Additional symptoms included nausea, diarrhea, and myalgia. His vital signs were notable for a pulse of 41 beats/min. The physical examination was remarkable for significant weakness of the bilateral upper extremities, inability to bear his own weight, and bilateral lower extremity edema. His initial ECG upon arrival showed bradycardia with wide QRS, absent P waves, and peaked T waves (Figure 1a). These findings differed from his baseline ECG taken 1 year earlier, which showed sinus rhythm with premature atrial complexes and an old right bundle branch block (Figure 1b).

Medication review revealed that the patient was currently prescribed 100 mg allopurinol daily, 2.5 mg amlodipine daily, 10 mg atorvastatin at bedtime, 4 mg doxazosin daily, 112 mcg levothyroxine daily, 100 mg losartan daily, 25 mg metoprolol daily, and 0.4 mg tamsulosin daily. The patient had also been taking over-the-counter indomethacin for knee pain.

Based on the ECG results, he was treated with 0.083%/6 mL nebulized albuterol, 4.65 Mq/250 mL saline solution intravenous (IV) calcium gluconate, 10 units IV insulin with concomitant 50%/25 mL IV dextrose and 8.4 g of oral patiromer suspension. IV furosemide was held due to concern for renal function. The decision to proceed with hemodialysis was made. Repeat laboratory tests were performed, and an ECG obtained after treatment initiation but prior to hemodialysis demonstrated improvement of rate and T wave shortening (Figure 1c). The serum potassium level dropped from 9.8 mEq/L to 7.9 mEq/L (reference range, 3.5-5.0 mEq/L) (Table 1).

In addition to hemodialysis, sodium zirconium 10 g orally 3 times daily was added. Laboratory test results and an ECG was performed after dialysis continued to demonstrate improvement (Figure 1d). The patient’s potassium level decreased to 5.8 mEq/L, with the ECG demonstrating stability of heart rate and further improvement of the PR interval, QRS complex, and T waves.

Despite the established treatment regimen, potassium levels again rose to 6.7 mEq/L, but there were no significant changes in the ECG, and thus no medication changes were made (Figure 1e). Subsequent monitoring demonstrated a further increase in potassium to 7.4 mEq/L, with an ECG demonstrating a return to the baseline of 1 year prior. The patient underwent hemodialysis again and was given oral furosemide 60 mg every 12 hours. The potassium concentration after dialysis decreased to 4.7 mEq/L and remained stable, not going above 5.0 mEq/L on subsequent monitoring. The patient had resolution of all symptoms and was discharged.

Discussion

We have described in detail the presentation of each pathology and mechanisms of each treatment, starting with the patient’s initial condition that brought him to the emergency room—muscle weakness. Skeletal muscle weakness is a common manifestation of hyperkalemia, occurring in 20% to 40% of cases, and is more prevalent in severe elevations of potassium. Rarely, the weakness can progress to flaccid paralysis of the patient’s extremities and, in extreme cases, the diaphragm.

Muscle weakness progression occurs in a manner that resembles Guillain-Barré syndrome, starting in the lower extremities and ascending toward the upper extremities.¹⁰ This is known as secondary hyperkalemic periodic paralysis. Hyperkalemia lowers the transmembrane gradient in neurons, leading to neuronal depolarization independent of the degree of hyperkalemia. If the degree of hyperkalemia is large enough, this depolarization inactivates voltage-gated sodium channels, making neurons refractory to excitation. Electromyographical studies have shown reduction in the compounded muscle action potential.¹¹ The transient nature of this paralysis is reflected by rapid correction of weakness and paralysis when the electrolyte disorder is corrected.

The patient in this case also presented with bradycardia. The ECG manifestations of hyperkalemia can include atrial asystole, intraventricular conduction disturbances, peaked T waves, and widened QRS complexes. However, some patients with renal insufficiency may not exhibit ECG changes despite significantly elevated serum potassium levels.¹²

The severity of hyperkalemia is crucial in determining the associated ECG changes, with levels > 6.0 mEq/L presenting with abnormalities.¹³ ECG findings alone may not always accurately reflect the severity of hyperkalemia, as up to 60% of patients with potassium levels > 6.0 mEq/L may not show ECG changes.¹⁴ Additionally, extreme hyperkalemia can lead to inconsistent ECG findings, making it challenging to rely solely on ECG for diagnosis and monitoring.⁸ The level of potassium that causes these effects varies widely through patient populations.

The main mechanism by which hyperkalemia affects the heart’s conduction system is through voltage differences across the conduction fibers and eventual steady-state inactivation of sodium channels. This combination of mechanisms shortens the action potential duration, allowing more cardiomyocytes to undergo synchronized depolarization. This amalgamation of cardiomyocytes repolarizing can be reflected on ECGs as peaked T waves. As the action potential decreases, there is a period during which cardiomyocytes are prone to tachyarrhythmias and ventricular fibrillation.

A reduced action potential may lead to increased rates of depolarization and thus conduction, which in some scenarios may increase heart rate. As the levels of potassium rise, intracellular accumulation impedes the entry of sodium by decreasing the cation gradient across the cell membrane. This effectively slows the sinus nodes and prolongs the QRS by slowing the overall propagation of action potentials. By this mechanism, conduction delays, blocks, or asystole are manifested. The patient in this case showed conduction delays, peaked T waves, and disappearance of P waves when he first arrived.

Hyperkalemia Treatment

Hyperkalemia develops most commonly due to acute or chronic kidney diseases, as was the case with this patient. The patient’s hyperkalemia was also augmented by the use of nonsteroidal anti-inflammatory drugs (NSAIDs), which can directly affect renal function. A properly functioning kidney is responsible for excretion of up to 90% of ingested potassium, while the remainder is excreted through the gastrointestinal (GI) tract. Definitive treatment of hyperkalemia is mitigated primarily through these 2 organ systems. The treatment also includes transitory mechanisms of potassium reduction. The goal of each method is to preserve the action potential of cardiomyocytes and myocytes. This patient presented with acute symptomatic hyperkalemia and received various medications to acutely, transitorily, and definitively treat it.

Initial therapy included calcium gluconate, which functions to stabilize the myocardial cell membrane. Hyperkalemia decreases the resting membrane action potential of excitable cells and predisposes them to early depolarization and thus dysrhythmias. Calcium decreases the threshold potential across cells and offsets the overall gradient back to near normal levels.¹⁵ Calcium can be delivered through calcium gluconate or calcium chloride. Calcium chloride is not preferred because extravasation can cause pain, blistering and tissue ischemia. Central venous access is required, potentially delaying prompt treatment. Calcium acts rapidly after administration—within 1 to 3 minutes—but only lasts 30 to 60 minutes.¹⁶ Administration of calcium gluconate can be repeated as often as necessary, but patients must be monitored for adverse effects of calcium such as nausea, abdominal pain, polydipsia, polyuria, muscle weakness, and paresthesia. Care must be taken when patients are taking digoxin, because calcium may potentiate toxicity.¹⁷ Although calcium provides immediate benefits it does little to correct the underlying cause; other medications are required to remove potassium from the body.

Two medication classes have been proven to shift potassium intracellularly. The first are β-2 agonists, such as albuterol/levalbuterol, and the second is insulin. Both work through sodium-potassium-ATPase in a direct manner. β-2 agonists stimulate sodium-potassium-ATPase to move more potassium intracellularly, but these effects have been seen only with high doses of albuterol, typically 4× the standard dose of 0.5 mg in nebulized solutions to achieve decreases in potassium of 0.3 to 0.6 mEq/L, although some trials have reported decreases of 0.62 to 0.98 mEq/L.^15,18 These potassium-lowering effects of β-2 agonist are modest, but can be seen 20 to 30 minutes after administration and persist up to 1 to 2 hours. β-2 agonists are also readily affected by β blockers, which may reduce or negate the desired effect in hyperkalemia. For these reasons, a β-2 agonist should not be given as monotherapy and should be provided as an adjuvant to more independent therapies such as insulin. Insulin binds to receptors on muscle cells and increases the quantity of sodium-potassium-ATPase and glucose transporters. With this increase in influx pumps, surrounding tissues with higher resting membrane potentials can absorb the potassium load, thereby protecting cardiomyocytes.

Potassium Removal

Three methods are currently available to remove potassium from the body: GI excretion, renal excretion, and direct removal from the bloodstream. Under normal physiologic conditions, the kidneys account for about 90% of the body’s ability to remove potassium. Loop diuretics facilitate the removal of potassium by increasing urine production and have an additional potassium-wasting effect. Although the onset of action of loop diuretics is typically 30 to 60 minutes after oral administration, their effect can last for several hours. In this patient, furosemide was introduced later in the treatment plan to manage recurring hyperkalemia by enhancing renal potassium excretion.

Potassium binders such as patiromer act in the GI tract, effectively reducing serum potassium levels although with a slower onset of action than furosemide, generally taking hours to days to exert its effect. Both medications illustrate a tailored approach to managing potassium levels, adapted to the evolving needs and renal function of the patient. The last method is using hemodialysis—by far the most rapid method to remove potassium, but also the most invasive. The different methods of treating hyperkalemia are summarized in Table 2. This patient required multiple days of hemodialysis to completely correct the electrolyte disorder. Upon discharge, the patient continued oral furosemide 40 mg daily and eventually discontinued hemodialysis due to stable renal function.

Often, after correcting an inciting event, potassium stores in the body eventually stabilize and do not require additional follow-up. Patients prone to hyperkalemia should be thoroughly educated on medications to avoid (NSAIDs, ACEIs/ARBs, trimethoprim), an adequate low potassium diet, and symptoms that may warrant medical attention.¹⁹

Conclusions

This case illustrates the importance of recognizing the spectrum of manifestations of hyperkalemia, which ranged from muscle weakness to cardiac dysrhythmias. Management strategies for the patient included stabilization of cardiac membranes, potassium shifting, and potassium removal, each tailored to the patient’s individual clinical findings.

The case further illustrates the critical role of continuous monitoring and dynamic adjustment of therapeutic strategies in response to evolving clinical and laboratory findings. The initial and subsequent ECGs, alongside laboratory tests, were instrumental in guiding the adjustments needed in the treatment regimen, ensuring both the efficacy and safety of the interventions. This proactive approach can mitigate the risk of recurrent hyperkalemia and its complications.

Hyperkalemia involves elevated serum potassium levels (> 5.0 mEq/L) and represents an important electrolyte disturbance due to its potentially severe consequences, including cardiac effects that can lead to dysrhythmia and even asystole and death.^1,2 In a US Medicare population, the prevalence of hyperkalemia has been estimated at 2.7% and is associated with substantial health care costs.³ The prevalence is even more marked in patients with preexisting conditions such as chronic kidney disease (CKD) and heart failure.^4,5

Hyperkalemia can result from multiple factors, including impaired renal function, adrenal disease, adverse drug reactions of angiotensin-converting enzyme inhibitors (ACEIs) and other medications, and heritable mutations.⁶ Hyperkalemia poses a considerable clinical risk, associated with adverse outcomes such as myocardial infarction and increased mortality in patients with CKD.^5,7,8 Electrocardiographic (ECG) changes associated with hyperkalemia play a vital role in guiding clinical decisions and treatment strategies.⁹ Understanding the pathophysiology, risk factors, and consequences of hyperkalemia, as well as the significance of ECG changes in its management, is essential for health care practitioners.

Case Presentation

An 81-year-old Hispanic man with a history of hypertension, hypothyroidism, gout, and CKD stage 3B presented to the emergency department with progressive weakness resulting in falls and culminating in an inability to ambulate independently. Additional symptoms included nausea, diarrhea, and myalgia. His vital signs were notable for a pulse of 41 beats/min. The physical examination was remarkable for significant weakness of the bilateral upper extremities, inability to bear his own weight, and bilateral lower extremity edema. His initial ECG upon arrival showed bradycardia with wide QRS, absent P waves, and peaked T waves (Figure 1a). These findings differed from his baseline ECG taken 1 year earlier, which showed sinus rhythm with premature atrial complexes and an old right bundle branch block (Figure 1b).

Medication review revealed that the patient was currently prescribed 100 mg allopurinol daily, 2.5 mg amlodipine daily, 10 mg atorvastatin at bedtime, 4 mg doxazosin daily, 112 mcg levothyroxine daily, 100 mg losartan daily, 25 mg metoprolol daily, and 0.4 mg tamsulosin daily. The patient had also been taking over-the-counter indomethacin for knee pain.

Based on the ECG results, he was treated with 0.083%/6 mL nebulized albuterol, 4.65 Mq/250 mL saline solution intravenous (IV) calcium gluconate, 10 units IV insulin with concomitant 50%/25 mL IV dextrose and 8.4 g of oral patiromer suspension. IV furosemide was held due to concern for renal function. The decision to proceed with hemodialysis was made. Repeat laboratory tests were performed, and an ECG obtained after treatment initiation but prior to hemodialysis demonstrated improvement of rate and T wave shortening (Figure 1c). The serum potassium level dropped from 9.8 mEq/L to 7.9 mEq/L (reference range, 3.5-5.0 mEq/L) (Table 1).

In addition to hemodialysis, sodium zirconium 10 g orally 3 times daily was added. Laboratory test results and an ECG was performed after dialysis continued to demonstrate improvement (Figure 1d). The patient’s potassium level decreased to 5.8 mEq/L, with the ECG demonstrating stability of heart rate and further improvement of the PR interval, QRS complex, and T waves.

Despite the established treatment regimen, potassium levels again rose to 6.7 mEq/L, but there were no significant changes in the ECG, and thus no medication changes were made (Figure 1e). Subsequent monitoring demonstrated a further increase in potassium to 7.4 mEq/L, with an ECG demonstrating a return to the baseline of 1 year prior. The patient underwent hemodialysis again and was given oral furosemide 60 mg every 12 hours. The potassium concentration after dialysis decreased to 4.7 mEq/L and remained stable, not going above 5.0 mEq/L on subsequent monitoring. The patient had resolution of all symptoms and was discharged.

Discussion

We have described in detail the presentation of each pathology and mechanisms of each treatment, starting with the patient’s initial condition that brought him to the emergency room—muscle weakness. Skeletal muscle weakness is a common manifestation of hyperkalemia, occurring in 20% to 40% of cases, and is more prevalent in severe elevations of potassium. Rarely, the weakness can progress to flaccid paralysis of the patient’s extremities and, in extreme cases, the diaphragm.

Muscle weakness progression occurs in a manner that resembles Guillain-Barré syndrome, starting in the lower extremities and ascending toward the upper extremities.¹⁰ This is known as secondary hyperkalemic periodic paralysis. Hyperkalemia lowers the transmembrane gradient in neurons, leading to neuronal depolarization independent of the degree of hyperkalemia. If the degree of hyperkalemia is large enough, this depolarization inactivates voltage-gated sodium channels, making neurons refractory to excitation. Electromyographical studies have shown reduction in the compounded muscle action potential.¹¹ The transient nature of this paralysis is reflected by rapid correction of weakness and paralysis when the electrolyte disorder is corrected.

The patient in this case also presented with bradycardia. The ECG manifestations of hyperkalemia can include atrial asystole, intraventricular conduction disturbances, peaked T waves, and widened QRS complexes. However, some patients with renal insufficiency may not exhibit ECG changes despite significantly elevated serum potassium levels.¹²

The severity of hyperkalemia is crucial in determining the associated ECG changes, with levels > 6.0 mEq/L presenting with abnormalities.¹³ ECG findings alone may not always accurately reflect the severity of hyperkalemia, as up to 60% of patients with potassium levels > 6.0 mEq/L may not show ECG changes.¹⁴ Additionally, extreme hyperkalemia can lead to inconsistent ECG findings, making it challenging to rely solely on ECG for diagnosis and monitoring.⁸ The level of potassium that causes these effects varies widely through patient populations.

The main mechanism by which hyperkalemia affects the heart’s conduction system is through voltage differences across the conduction fibers and eventual steady-state inactivation of sodium channels. This combination of mechanisms shortens the action potential duration, allowing more cardiomyocytes to undergo synchronized depolarization. This amalgamation of cardiomyocytes repolarizing can be reflected on ECGs as peaked T waves. As the action potential decreases, there is a period during which cardiomyocytes are prone to tachyarrhythmias and ventricular fibrillation.

A reduced action potential may lead to increased rates of depolarization and thus conduction, which in some scenarios may increase heart rate. As the levels of potassium rise, intracellular accumulation impedes the entry of sodium by decreasing the cation gradient across the cell membrane. This effectively slows the sinus nodes and prolongs the QRS by slowing the overall propagation of action potentials. By this mechanism, conduction delays, blocks, or asystole are manifested. The patient in this case showed conduction delays, peaked T waves, and disappearance of P waves when he first arrived.

Hyperkalemia Treatment

Hyperkalemia develops most commonly due to acute or chronic kidney diseases, as was the case with this patient. The patient’s hyperkalemia was also augmented by the use of nonsteroidal anti-inflammatory drugs (NSAIDs), which can directly affect renal function. A properly functioning kidney is responsible for excretion of up to 90% of ingested potassium, while the remainder is excreted through the gastrointestinal (GI) tract. Definitive treatment of hyperkalemia is mitigated primarily through these 2 organ systems. The treatment also includes transitory mechanisms of potassium reduction. The goal of each method is to preserve the action potential of cardiomyocytes and myocytes. This patient presented with acute symptomatic hyperkalemia and received various medications to acutely, transitorily, and definitively treat it.

Initial therapy included calcium gluconate, which functions to stabilize the myocardial cell membrane. Hyperkalemia decreases the resting membrane action potential of excitable cells and predisposes them to early depolarization and thus dysrhythmias. Calcium decreases the threshold potential across cells and offsets the overall gradient back to near normal levels.¹⁵ Calcium can be delivered through calcium gluconate or calcium chloride. Calcium chloride is not preferred because extravasation can cause pain, blistering and tissue ischemia. Central venous access is required, potentially delaying prompt treatment. Calcium acts rapidly after administration—within 1 to 3 minutes—but only lasts 30 to 60 minutes.¹⁶ Administration of calcium gluconate can be repeated as often as necessary, but patients must be monitored for adverse effects of calcium such as nausea, abdominal pain, polydipsia, polyuria, muscle weakness, and paresthesia. Care must be taken when patients are taking digoxin, because calcium may potentiate toxicity.¹⁷ Although calcium provides immediate benefits it does little to correct the underlying cause; other medications are required to remove potassium from the body.

Two medication classes have been proven to shift potassium intracellularly. The first are β-2 agonists, such as albuterol/levalbuterol, and the second is insulin. Both work through sodium-potassium-ATPase in a direct manner. β-2 agonists stimulate sodium-potassium-ATPase to move more potassium intracellularly, but these effects have been seen only with high doses of albuterol, typically 4× the standard dose of 0.5 mg in nebulized solutions to achieve decreases in potassium of 0.3 to 0.6 mEq/L, although some trials have reported decreases of 0.62 to 0.98 mEq/L.^15,18 These potassium-lowering effects of β-2 agonist are modest, but can be seen 20 to 30 minutes after administration and persist up to 1 to 2 hours. β-2 agonists are also readily affected by β blockers, which may reduce or negate the desired effect in hyperkalemia. For these reasons, a β-2 agonist should not be given as monotherapy and should be provided as an adjuvant to more independent therapies such as insulin. Insulin binds to receptors on muscle cells and increases the quantity of sodium-potassium-ATPase and glucose transporters. With this increase in influx pumps, surrounding tissues with higher resting membrane potentials can absorb the potassium load, thereby protecting cardiomyocytes.

Potassium Removal

Three methods are currently available to remove potassium from the body: GI excretion, renal excretion, and direct removal from the bloodstream. Under normal physiologic conditions, the kidneys account for about 90% of the body’s ability to remove potassium. Loop diuretics facilitate the removal of potassium by increasing urine production and have an additional potassium-wasting effect. Although the onset of action of loop diuretics is typically 30 to 60 minutes after oral administration, their effect can last for several hours. In this patient, furosemide was introduced later in the treatment plan to manage recurring hyperkalemia by enhancing renal potassium excretion.

Potassium binders such as patiromer act in the GI tract, effectively reducing serum potassium levels although with a slower onset of action than furosemide, generally taking hours to days to exert its effect. Both medications illustrate a tailored approach to managing potassium levels, adapted to the evolving needs and renal function of the patient. The last method is using hemodialysis—by far the most rapid method to remove potassium, but also the most invasive. The different methods of treating hyperkalemia are summarized in Table 2. This patient required multiple days of hemodialysis to completely correct the electrolyte disorder. Upon discharge, the patient continued oral furosemide 40 mg daily and eventually discontinued hemodialysis due to stable renal function.

Often, after correcting an inciting event, potassium stores in the body eventually stabilize and do not require additional follow-up. Patients prone to hyperkalemia should be thoroughly educated on medications to avoid (NSAIDs, ACEIs/ARBs, trimethoprim), an adequate low potassium diet, and symptoms that may warrant medical attention.¹⁹

Conclusions

This case illustrates the importance of recognizing the spectrum of manifestations of hyperkalemia, which ranged from muscle weakness to cardiac dysrhythmias. Management strategies for the patient included stabilization of cardiac membranes, potassium shifting, and potassium removal, each tailored to the patient’s individual clinical findings.

The case further illustrates the critical role of continuous monitoring and dynamic adjustment of therapeutic strategies in response to evolving clinical and laboratory findings. The initial and subsequent ECGs, alongside laboratory tests, were instrumental in guiding the adjustments needed in the treatment regimen, ensuring both the efficacy and safety of the interventions. This proactive approach can mitigate the risk of recurrent hyperkalemia and its complications.

Hyperkalemia involves elevated serum potassium levels (> 5.0 mEq/L) and represents an important electrolyte disturbance due to its potentially severe consequences, including cardiac effects that can lead to dysrhythmia and even asystole and death.^1,2 In a US Medicare population, the prevalence of hyperkalemia has been estimated at 2.7% and is associated with substantial health care costs.³ The prevalence is even more marked in patients with preexisting conditions such as chronic kidney disease (CKD) and heart failure.^4,5

Hyperkalemia can result from multiple factors, including impaired renal function, adrenal disease, adverse drug reactions of angiotensin-converting enzyme inhibitors (ACEIs) and other medications, and heritable mutations.⁶ Hyperkalemia poses a considerable clinical risk, associated with adverse outcomes such as myocardial infarction and increased mortality in patients with CKD.^5,7,8 Electrocardiographic (ECG) changes associated with hyperkalemia play a vital role in guiding clinical decisions and treatment strategies.⁹ Understanding the pathophysiology, risk factors, and consequences of hyperkalemia, as well as the significance of ECG changes in its management, is essential for health care practitioners.

Case Presentation

An 81-year-old Hispanic man with a history of hypertension, hypothyroidism, gout, and CKD stage 3B presented to the emergency department with progressive weakness resulting in falls and culminating in an inability to ambulate independently. Additional symptoms included nausea, diarrhea, and myalgia. His vital signs were notable for a pulse of 41 beats/min. The physical examination was remarkable for significant weakness of the bilateral upper extremities, inability to bear his own weight, and bilateral lower extremity edema. His initial ECG upon arrival showed bradycardia with wide QRS, absent P waves, and peaked T waves (Figure 1a). These findings differed from his baseline ECG taken 1 year earlier, which showed sinus rhythm with premature atrial complexes and an old right bundle branch block (Figure 1b).

Medication review revealed that the patient was currently prescribed 100 mg allopurinol daily, 2.5 mg amlodipine daily, 10 mg atorvastatin at bedtime, 4 mg doxazosin daily, 112 mcg levothyroxine daily, 100 mg losartan daily, 25 mg metoprolol daily, and 0.4 mg tamsulosin daily. The patient had also been taking over-the-counter indomethacin for knee pain.

Based on the ECG results, he was treated with 0.083%/6 mL nebulized albuterol, 4.65 Mq/250 mL saline solution intravenous (IV) calcium gluconate, 10 units IV insulin with concomitant 50%/25 mL IV dextrose and 8.4 g of oral patiromer suspension. IV furosemide was held due to concern for renal function. The decision to proceed with hemodialysis was made. Repeat laboratory tests were performed, and an ECG obtained after treatment initiation but prior to hemodialysis demonstrated improvement of rate and T wave shortening (Figure 1c). The serum potassium level dropped from 9.8 mEq/L to 7.9 mEq/L (reference range, 3.5-5.0 mEq/L) (Table 1).

In addition to hemodialysis, sodium zirconium 10 g orally 3 times daily was added. Laboratory test results and an ECG was performed after dialysis continued to demonstrate improvement (Figure 1d). The patient’s potassium level decreased to 5.8 mEq/L, with the ECG demonstrating stability of heart rate and further improvement of the PR interval, QRS complex, and T waves.

Despite the established treatment regimen, potassium levels again rose to 6.7 mEq/L, but there were no significant changes in the ECG, and thus no medication changes were made (Figure 1e). Subsequent monitoring demonstrated a further increase in potassium to 7.4 mEq/L, with an ECG demonstrating a return to the baseline of 1 year prior. The patient underwent hemodialysis again and was given oral furosemide 60 mg every 12 hours. The potassium concentration after dialysis decreased to 4.7 mEq/L and remained stable, not going above 5.0 mEq/L on subsequent monitoring. The patient had resolution of all symptoms and was discharged.

Discussion

We have described in detail the presentation of each pathology and mechanisms of each treatment, starting with the patient’s initial condition that brought him to the emergency room—muscle weakness. Skeletal muscle weakness is a common manifestation of hyperkalemia, occurring in 20% to 40% of cases, and is more prevalent in severe elevations of potassium. Rarely, the weakness can progress to flaccid paralysis of the patient’s extremities and, in extreme cases, the diaphragm.

Muscle weakness progression occurs in a manner that resembles Guillain-Barré syndrome, starting in the lower extremities and ascending toward the upper extremities.¹⁰ This is known as secondary hyperkalemic periodic paralysis. Hyperkalemia lowers the transmembrane gradient in neurons, leading to neuronal depolarization independent of the degree of hyperkalemia. If the degree of hyperkalemia is large enough, this depolarization inactivates voltage-gated sodium channels, making neurons refractory to excitation. Electromyographical studies have shown reduction in the compounded muscle action potential.¹¹ The transient nature of this paralysis is reflected by rapid correction of weakness and paralysis when the electrolyte disorder is corrected.

The patient in this case also presented with bradycardia. The ECG manifestations of hyperkalemia can include atrial asystole, intraventricular conduction disturbances, peaked T waves, and widened QRS complexes. However, some patients with renal insufficiency may not exhibit ECG changes despite significantly elevated serum potassium levels.¹²

The severity of hyperkalemia is crucial in determining the associated ECG changes, with levels > 6.0 mEq/L presenting with abnormalities.¹³ ECG findings alone may not always accurately reflect the severity of hyperkalemia, as up to 60% of patients with potassium levels > 6.0 mEq/L may not show ECG changes.¹⁴ Additionally, extreme hyperkalemia can lead to inconsistent ECG findings, making it challenging to rely solely on ECG for diagnosis and monitoring.⁸ The level of potassium that causes these effects varies widely through patient populations.

The main mechanism by which hyperkalemia affects the heart’s conduction system is through voltage differences across the conduction fibers and eventual steady-state inactivation of sodium channels. This combination of mechanisms shortens the action potential duration, allowing more cardiomyocytes to undergo synchronized depolarization. This amalgamation of cardiomyocytes repolarizing can be reflected on ECGs as peaked T waves. As the action potential decreases, there is a period during which cardiomyocytes are prone to tachyarrhythmias and ventricular fibrillation.

A reduced action potential may lead to increased rates of depolarization and thus conduction, which in some scenarios may increase heart rate. As the levels of potassium rise, intracellular accumulation impedes the entry of sodium by decreasing the cation gradient across the cell membrane. This effectively slows the sinus nodes and prolongs the QRS by slowing the overall propagation of action potentials. By this mechanism, conduction delays, blocks, or asystole are manifested. The patient in this case showed conduction delays, peaked T waves, and disappearance of P waves when he first arrived.

Hyperkalemia Treatment

Hyperkalemia develops most commonly due to acute or chronic kidney diseases, as was the case with this patient. The patient’s hyperkalemia was also augmented by the use of nonsteroidal anti-inflammatory drugs (NSAIDs), which can directly affect renal function. A properly functioning kidney is responsible for excretion of up to 90% of ingested potassium, while the remainder is excreted through the gastrointestinal (GI) tract. Definitive treatment of hyperkalemia is mitigated primarily through these 2 organ systems. The treatment also includes transitory mechanisms of potassium reduction. The goal of each method is to preserve the action potential of cardiomyocytes and myocytes. This patient presented with acute symptomatic hyperkalemia and received various medications to acutely, transitorily, and definitively treat it.

Initial therapy included calcium gluconate, which functions to stabilize the myocardial cell membrane. Hyperkalemia decreases the resting membrane action potential of excitable cells and predisposes them to early depolarization and thus dysrhythmias. Calcium decreases the threshold potential across cells and offsets the overall gradient back to near normal levels.¹⁵ Calcium can be delivered through calcium gluconate or calcium chloride. Calcium chloride is not preferred because extravasation can cause pain, blistering and tissue ischemia. Central venous access is required, potentially delaying prompt treatment. Calcium acts rapidly after administration—within 1 to 3 minutes—but only lasts 30 to 60 minutes.¹⁶ Administration of calcium gluconate can be repeated as often as necessary, but patients must be monitored for adverse effects of calcium such as nausea, abdominal pain, polydipsia, polyuria, muscle weakness, and paresthesia. Care must be taken when patients are taking digoxin, because calcium may potentiate toxicity.¹⁷ Although calcium provides immediate benefits it does little to correct the underlying cause; other medications are required to remove potassium from the body.

Two medication classes have been proven to shift potassium intracellularly. The first are β-2 agonists, such as albuterol/levalbuterol, and the second is insulin. Both work through sodium-potassium-ATPase in a direct manner. β-2 agonists stimulate sodium-potassium-ATPase to move more potassium intracellularly, but these effects have been seen only with high doses of albuterol, typically 4× the standard dose of 0.5 mg in nebulized solutions to achieve decreases in potassium of 0.3 to 0.6 mEq/L, although some trials have reported decreases of 0.62 to 0.98 mEq/L.^15,18 These potassium-lowering effects of β-2 agonist are modest, but can be seen 20 to 30 minutes after administration and persist up to 1 to 2 hours. β-2 agonists are also readily affected by β blockers, which may reduce or negate the desired effect in hyperkalemia. For these reasons, a β-2 agonist should not be given as monotherapy and should be provided as an adjuvant to more independent therapies such as insulin. Insulin binds to receptors on muscle cells and increases the quantity of sodium-potassium-ATPase and glucose transporters. With this increase in influx pumps, surrounding tissues with higher resting membrane potentials can absorb the potassium load, thereby protecting cardiomyocytes.

Potassium Removal

Three methods are currently available to remove potassium from the body: GI excretion, renal excretion, and direct removal from the bloodstream. Under normal physiologic conditions, the kidneys account for about 90% of the body’s ability to remove potassium. Loop diuretics facilitate the removal of potassium by increasing urine production and have an additional potassium-wasting effect. Although the onset of action of loop diuretics is typically 30 to 60 minutes after oral administration, their effect can last for several hours. In this patient, furosemide was introduced later in the treatment plan to manage recurring hyperkalemia by enhancing renal potassium excretion.

Potassium binders such as patiromer act in the GI tract, effectively reducing serum potassium levels although with a slower onset of action than furosemide, generally taking hours to days to exert its effect. Both medications illustrate a tailored approach to managing potassium levels, adapted to the evolving needs and renal function of the patient. The last method is using hemodialysis—by far the most rapid method to remove potassium, but also the most invasive. The different methods of treating hyperkalemia are summarized in Table 2. This patient required multiple days of hemodialysis to completely correct the electrolyte disorder. Upon discharge, the patient continued oral furosemide 40 mg daily and eventually discontinued hemodialysis due to stable renal function.

Often, after correcting an inciting event, potassium stores in the body eventually stabilize and do not require additional follow-up. Patients prone to hyperkalemia should be thoroughly educated on medications to avoid (NSAIDs, ACEIs/ARBs, trimethoprim), an adequate low potassium diet, and symptoms that may warrant medical attention.¹⁹

Conclusions

This case illustrates the importance of recognizing the spectrum of manifestations of hyperkalemia, which ranged from muscle weakness to cardiac dysrhythmias. Management strategies for the patient included stabilization of cardiac membranes, potassium shifting, and potassium removal, each tailored to the patient’s individual clinical findings.

The case further illustrates the critical role of continuous monitoring and dynamic adjustment of therapeutic strategies in response to evolving clinical and laboratory findings. The initial and subsequent ECGs, alongside laboratory tests, were instrumental in guiding the adjustments needed in the treatment regimen, ensuring both the efficacy and safety of the interventions. This proactive approach can mitigate the risk of recurrent hyperkalemia and its complications.