Surgical Technique Case Series: utilizing direct skin neurotization as a novel approach for the prevention of neuropathic pain and improvement in sensation after digit amputation

Introduction: The current, mainstay surgical prophylaxis for neuropathic and phantom limb pain post amputation, namely targeted muscle reinnervation (TMR), presents complexities in the setting of digit amputation, given the sparsity of distal motor nerve targets. In this case series, we describe a novel approach of direct skin neurotization on distal sensory targets post amputation. This technique draws upon the principles of targeted sensory reinnervation (TSR) and targeted nipple reinnervation (TNR) as alternatives to limit the onset of neuropathic and phantom limb pain postoperatively. Methods: We performed a retrospective analysis of clinical outcomes over a 5-year period (2020–2024). This series includes two patients: a 66-year-old male treated for lentiginous melanoma of the left thumb in 2020 and a 57-year-old male treated for squamous cell carcinoma (SCC) of the left index finger in 2022, with a subsequent recurrent SCC in the left small digit in 2024. Clinical data were reviewed to evaluate surgical results and pain outcomes, specifically the onset and resolution of neuropathic pain. Results: The first patient underwent amputation of the left thumb at the interphalangeal joint with direct skin neurotization. Postoperatively, he demonstrated improved digit sensation and reported minimal neuropathic pain. The second patient initially underwent amputation of the left index finger at the DIP joint with direct skin neurotization in 2022; later, in 2024, he required amputation of the left small digit for recurrent SCC, which was performed with standard traction neurectomy. Notably, this patient reported minimal neuropathic pain 3 months following the initial neurotization procedure. Conversely, following the subsequent traction neurectomy, he experienced significant neuropathic pain and minimal sensory improvement. Conclusion: The use of direct skin neurotization, an adaptation of the principles of TSR and TNR, may improve skin sensation and prevent or reduce neuropathic pain in distal digital amputations where motor targets for TMR are unavailable.