Prevalence of Comorbid Psychiatric Conditions and Chronic Pain in Patients Seeking Peripheral Nerve Surgery.

Background: In peripheral nerve surgery, the presence of psychiatric diagnoses and medications may affect outcomes and perioperative neuropathic pain management. The purpose of this study was to determine the prevalence of psychiatric diagnoses and chronic pain in patients referred to a peripheral nerve surgery clinic. Methods: This is a retrospective review of patients seen at a peripheral nerve clinic from July 1, 2017 to June 30, 2021. Medical records were reviewed for demographics; peripheral nerve diagnosis; psychiatric diagnoses; psychotropic prescriptions; use of nonneuroleptic/nonnarcotic, neuroleptic, and narcotic medications; and peripheral nerve surgical candidacy and outcome. Results: Six hundred twenty-two patients were included in this study. The most common reasons for referral were 24.8% lower extremity neuroma, 23.2% lower extremity compressive neuropathy, and 14.0% upper extremity compressive neuropathy. Of the included patients' 37.1% had a psychiatric diagnosis, and 36.3% were taking a psychotropic medication. The percentage of patients taking chronic nonneuroleptic/nonnarcotic pain medications was 34.3%' with 42.8% taking neuroleptic, and 24.9% narcotic medications. Patients with a psychiatric diagnosis were more likely to be taking neuroleptic (48.9% versus 38.9%, P < 0.001) and narcotic pain medications (27.3% versus 17.4%, P = 0.004) and less likely to have a positive surgical outcome (65.7% versus 83.0%, P = 0.001). Conclusions: Patients referred to a peripheral nerve surgery clinic frequently have psychiatric diagnoses and take chronic psychotropic and chronic pain medications. Knowledge of this will best help the peripheral nerve surgeon evaluate a patient for surgery, optimize perioperative care, and safely and effectively manage expectations.

Incidence and Nerve Distribution of Symptomatic Neuromas and Phantom Limb Pain after Below-Knee Amputation.

BACKGROUND: Patients with major lower limb amputations suffer from symptomatic neuromas and phantom-limb pain due to their transected nerves. Peripheral nerve surgery techniques, such as targeted muscle reinnervation and regenerative peripheral nerve interface, aim to physiologically prevent this nerve-specific pain. No studies have specifically reported on which nerves most frequently cause chronic pain. The authors studied the nerve-specific incidence of symptomatic neuroma formation and phantom limb pain in patients undergoing a below-knee amputation, to better tailor use of targeted muscle reinnervation and regenerative peripheral nerve interface. METHODS: This was a retrospective review of all patients undergoing a below-knee amputation from January 1, 2013, to December 31, 2018, at MedStar Georgetown University Hospital. All below-knee amputations were performed with a posterior skin flap, myotenodesis, and traction neurectomies of all nerves. Postoperative notes were reviewed for the presence of a symptomatic neuroma, defined as localized pain and a Tinel sign over a known sensory nerve, and nerve-specific phantom limb pain, defined as pain of the missing limb corresponding to a known dermatome. RESULTS: One hundred ninety-eight patients were included in this study. The rate of symptomatic neuroma formation was 14.6 percent (29 of 198), with the superficial peroneal and saphenous nerves most often involved. Diabetes and obesity were protective against symptomatic neuroma formation. The rate of nerve-specific phantom limb pain was 12.6 percent (25 of 198) and highly correlated with the presence of a symptomatic neuroma. CONCLUSION: To optimize outcomes for amputees, it is critical that surgeons best understand what nerves are more likely to form symptomatic neuromas and lead to nerve-specific phantom limb pain, so that surgeons can best tailor primary or secondary management of the major sensory nerves. CLINICAL QUESTION/LEVEL OF EVIDENCE: Risk, III.

Targeted Muscle Reinnervation Improves Pain and Ambulation Outcomes in Highly Comorbid Amputees.

BACKGROUND: Approximately 200,000 people undergo a lower extremity amputation each year. Following amputation, patients suffer from chronic pain, inability to ambulate, and high mortality rates. Targeted muscle reinnervation is a nerve transfer procedure that redirects transected sensory and mixed nerves into motor nerves to treat neuroma and phantom limb pain. This study evaluates outcomes with prophylactic targeted muscle reinnervation at the time of below-knee amputation. METHODS: This is a cohort study comparing 100 patients undergoing below-knee amputation with primary targeted muscle reinnervation and 100 patients undergoing below-knee amputation with standard traction neurectomy and muscle implantation. Outcome metrics included the presence of residual and phantom limb pain, pain severity, opioid use, ambulation ability, and mortality rates. RESULTS: The targeted muscle reinnervation group was on average 60 years old with a body mass index of 29 kg/m2. Eighty-four percent had diabetes, 55 percent had peripheral vascular disease, and 43 percent had end-stage renal disease. Average follow-up was 9.6 months for the targeted muscle reinnervation group and 18.5 months for the nontargeted muscle reinnervation group. Seventy-one percent of targeted muscle reinnervation patients were pain free, compared with 36 percent (p < 0.01). Fourteen percent of targeted muscle reinnervation patients had residual limb pain, compared with 57 percent (p < 0.01). Nineteen percent of targeted muscle reinnervation patients had phantom limb pain, compared with 47 percent (p < 0.01). Six percent of targeted muscle reinnervation patients were on opioids, compared with 26 percent (p < 0.01); and 90.9 percent of targeted muscle reinnervation patients were ambulatory, compared with 70.5 percent (p < 0.01). CONCLUSION: Targeted muscle reinnervation reduces pain and improves ambulation in patients undergoing below-knee amputation, which may be critical in improving morbidity and mortality rates in this comorbid patient population. CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, III.

Targeted Muscle Reinnervation to Expendable Motor Nerves for the Treatment of Refractory Symptomatic Neuromas in Nonamputees.

Symptomatic neuromas can cause debilitating pain, significantly impairing patients' quality of life. There are numerous medical and surgical options for management. Targeted muscle reinnervation (TMR) is a nerve transfer procedure that is now commonly used to prevent or treat symptomatic neuromas or phantom limb pain in amputees. There are a few reports in the current literature about performing TMR in the nonamputee, but no cohort studies to date that report pain outcomes. This study evaluates TMR to treat symptomatic neuromas in nonamputee patients. This is a retrospective cohort study of all patients with symptomatic neuromas treated with TMR over a 1-year period from January 1,2019, to January 1, 2020, at MedStar Georgetown University Hospital. The neuromas are excised to healthy nerve fascicles, and a redundant donor motor fascicle is selected for nerve transfer. Patients were asked in clinic or via telephone about their preoperative and postoperative pain, function, and quality of life, and postoperative clinic notes were reviewed for complications and motor deficits. Fifteen patients were included in this study. Patients had symptomatic neuromas involving the upper extremity, lower extremity, and trunk. Pain frequency decreased from 6.7 times per week to 3.9 (P < 0.01) and from 9.1 times per day to 5.1 (P < 0.01). Pain severity decreased from an average of 7.9/10 to 4.3/10 (P < 0.01). Overall physical function increased from 3.7/10 to 5.8/10 (P = 0.01), and overall quality of life increased from 4.9/10 to 7.0/10 (P < 0.01). No patients had demonstrable weakness of the motor function of the donor nerve. Targeted muscle reinnervation is a viable surgical option for the treatment of symptomatic neuromas, particularly in those patients who have previously failed prior neuroma excisions.