Active Nerve Management for Below-knee Amputation: A Comparison of Approaches

Targeted muscle reinnervation and regenerative peripheral nerve interface (RPNI) are well-described techniques used to treat or prevent postamputation neuroma and phantom limb pain after below-knee amputation (BKA). These techniques can be performed via a posterior approach (PA) or a through-the-wound approach (TTWA). We performed a review of patients who underwent active nerve management at the time of BKA between February 2019 and May 2023. Patients were stratified into PA and TTWA cohorts. A total of 36 patients underwent active nerve management at the time of BKA-16 PA and 20 TTWA. The PA was found to take significantly longer than the TTWA, with an operative time of 251 minutes compared with 208 minutes, respectively (P = 0.03). All patients in both the TTWA and PA cohorts underwent targeted muscle reinnervation. However, in the TTWA cohort, 95% also underwent RPNI compared with 56% in the PA group (P = 0.01). Patients who underwent the TTWA were more likely to experience wound dehiscence postoperatively (TTWA, 40% of subjects; PA 25% of subjects; P = 0.01). There was no difference in infection rates or time to prosthetic clearance between groups. Though more time-consuming, the PA provides more direct access to recipient motor nerves, as evidenced by the lower use of RPNI nerve management in this cohort. These findings should be considered by surgeons who perform active nerve management at the time of BKA.