Necrotizing Fasciitis and Targeted Muscle Reinnervation in the Upper Extremity: A Case Report.

BACKGROUND Necrotizing fasciitis is a rare but increasingly prevalent, rapidly progressive soft tissue infection with high morbidity and mortality. While cases of lower limb involvement are more frequent, cases affecting the upper limb, especially leading to proximal major amputations, such as transhumeral amputation, are exceedingly rare. Targeted muscle reinnervation (TMR) is an innovative approach, aimed at improving postoperative outcomes and pain control. We report a case with sudden clinical presentation that was managed initially with emergency amputation. Postoperative neuroma-related pain was treated using TMR. CASE REPORT A 48-year-old man with untreated psoriasis sustained a right wrist crush injury. Initially discharged with mild contusion, he returned 48 h later with severe swelling, pain, and systemic symptoms. Imaging and laboratory test results indicated NF. Despite broad-spectrum antibiotics and ICU support, he developed septic shock and multi-organ failure. Six hours later, emergency transhumeral amputation was performed, with hemodynamic stabilization. After 2 additional debridements, he improved and was discharged. At 6 months, he had neuroma-related pain. TMR was performed, resolving the symptoms. He was in rehabilitation, awaiting prosthesis fitting and training, at the time of this report. CONCLUSIONS Upper limb NF is an uncommon but life-threatening condition requiring prompt diagnosis and aggressive treatment. The Laboratory Risk Indicator for Necrotizing Fasciitis score is a useful diagnostic tool, and early surgical intervention remains the cornerstone of therapy. When amputation is necessary, postoperative complications, including chronic and phantom limb pain, can occur. TMR is a promising surgical approach for reducing pain and improving function in upper limb amputees.