Comparison of 2 Regenerative Peripheral Nerve Interface Techniques for the Treatment of Rat Neuroma Pain.

Treatment of painful neuromas has long posed a significant challenge for peripheral nerve patients. The regenerative peripheral nerve interface (RPNI) provides the transected nerve with a muscle graft target to prevent neuroma formation. Discrepancies in RPNI surgical techniques between animal models ("inlay" RPNI) and clinical studies ("burrito" RPNI) preclude direct translation of results from bench to bedside and may account for variabilities in patient outcomes. The authors compared outcomes of these 2 surgical techniques in a rodent model. Animals treated with burrito RPNI after tibial nerve neuroma formation demonstrated no improvement in pain assessment, and tissue analysis revealed complete atrophy of the muscle graft with neuroma recurrence. By contrast, animals treated with inlay RPNI had significant improvement in pain with viable muscle grafts. The results suggest superiority of the inlay RPNI surgical technique for the management of painful neuroma in rodents.Clinical Relevance Statement:RPNIs are currently being used to prevent and treat neuroma and phantom limb pain. This preclinical study suggests the superiority of one surgical technique over the other.