Regenerative peripheral nerve interface following forequarter amputation: a case report

Forequarter amputation is a radical surgical procedure for malignant bone and soft tissue tumors involving the shoulder girdle, typically indicated for cases where limb salvage is not feasible due to extensive local invasion. However, post-amputation neuroma and phantom limb pain are major complications, occurring in 80%-90% of cases and severely impairing patients' quality of life. Traditional nerve management techniques often fail to prevent recurrent neuroma formation. The Regenerative Peripheral Nerve Interface (RPNI) is an emerging technique designed to guide axonal regeneration and mitigate pain. However, its application in oncologic high-level amputations has not been widely reported.

We report the case of a 68-year-old female who underwent forequarter amputation for a malignant tumor of the left upper arm with simultaneous prophylactic RPNI reconstruction. The main trunks of the brachial plexus were sharply transected, and their stumps were implanted into small segments of denervated free muscle graftsharvested from the brachioradialis muscle of the amputated limb to promote organized axonal regeneration.

The patient's postoperative course was uneventful, without infection or other complications. Follow-ups at 1, 3, 6, and 12 months demonstrated significant and sustained relief of residual limb pain. The Visual Analog Scale (VAS) score decreased from a preoperative level of 9 to 0 Crucially, the patient reported no phantom limb pain or symptomatic neuroma-related discomfort during follow-up. Final pathology confirmed osteosarcoma.

Concurrent RPNI reconstruction during forequarter amputation for malignancy is a safe and effective strategy to prevent postoperative neuropathic pain. This innovative application in high-level amputation patients offers a promising approach to improving quality of life.