Postoperative Pain Course and Factors Associated with Successful Pain Mitigation following Primary and Secondary Targeted Muscle Reinnervation in Amputees
Year: 2023
Type: article
Study design: Observational Study
Abstract: PURPOSE: Targeted Muscle Reinnervation (TMR) is an effective modality in the surgical management of neuropathic pain for amputees. TMR can be performed within 14 days of the amputation (primary TMR) for prevention of neuropathic pain, or secondarily (> 14 days post-op) for treatment of neuropathic pain (1-3). Patients may experience significant pain relief, and cases of remission or complete absence of pain have been reported. However, it is not known when pain relief is achieved and which patients benefit the most from this technique. METHODS: We examined the charts of 218 patients who underwent TMR at the Massachusetts General Hospital between 2017 and 2023. Demographic, epidemiological, and surgery-related data was collected and analyzed. Longitudinal data of pain scores collected with a 0-10 numerical pain scale were used to assess the postoperative pain course and factors associated with effective pain remission and prevention. Locally weighted scatterplot smoothing (LOWESS) curves were utilized to visualize postoperative pain courses. RESULTS: A total of 100 patients were included in the final analysis. Compared to Secondary TMR patients, primary TMR Patients (n = 47) reported lower pain scores, pain intensity, and pain interference up to 12 months post-op, with a statistically significant difference in pain levels at 3 and 6 months (p<0.05). Sustainable pain remission/prevention (pain level of 3/10 or lower for >3 months up until the last follow-up) was achieved for 52.3% of primary and 18.9% of secondary TMR patients. For primary TMR patients, 19.1% reported complete pain disappearance (NRS = 0 for more than 3 months until the last follow-up). This occurred in 1.9% of secondary TMR patients. Primary TMR patients have significantly higher odds (OR=4.89; 95% CI 1.84-13.37. p=0. 0003) of achieving sustained mild pain, than secondary TMR patients. Effective pain prevention in primary TMR patients was correlated with an absent history of psychiatric comorbidities and depression. In secondary TMR patients, higher BMI, distal amputation levels, lower preoperative pain interference scores, and absence of psychiatric diseases were significantly associated with sustainable pain remission. CONCLUSIONS: Patients undergoing primary TMR report lower pain scores overall and demonstrate a higher percentage of patients achieving optimal outcomes. Psychiatric comorbidities appear to be a risk factor for worse outcomes in both groups and we associate further epidemiological characteristics to an increased likelihood of successful outcomes in secondary TMR patients. References: 1. Kuiken TA, Barlow AK, Hargrove LJ, Dumanian GA. Targeted muscle reinnervation for the upper and lower extremity. Tech Orthop. 2017;32(2):109-116. 2. Dumanian GA, Potter BK, Mioton LM, et al. Targeted Muscle Reinnervation Treats Neuroma and Phantom Pain in Major Limb Amputees: A Randomized Clinical Trial. Ann Surg. 2019;270(2):238-246. 3. O’Brien AL, Jordan SW, West JM, Mioton LM, Dumanian GA, Valerio IL. Targeted Muscle Reinnervation at the Time of Upper-Extremity Amputation for the Treatment of Pain Severity and Symptoms. J Hand Surg Am. 2021;46(1):72.e1-72.e10.
Institution: Harvard University
Language: English
Subfield: Anesthesiology and Pain Medicine
Field: Medicine
Domain: Health Sciences
Open Access status: gold
Estimated APC paid: $2,195
OpenAlex ID: W4387738688