A Multicenter Matched Cohort Study of Processed Nerve Allograft and Autograft in Mixed and Motor Nerve Reconstruction.

Purpose: Nerve transections often require surgical intervention with a bridging material to achieve meaningful recovery (MR). We explored similar cohorts with nerve reconstruction using nerve autograft or nerve allograft. We hypothesized that motor recovery in mixed and motor nerve injuries repaired with nerve allograft is noninferior to repairs with nerve autograft. Methods: Subjects had mixed or motor nerve transections in the upper extremity distal to the axilla surgically repaired with nerve autograft or nerve allograft. Motor recovery outcomes were analyzed using the British Medical Research Council Classification (MRCC) with MR defined as ≥M3 and enhanced MR defined as ≥M4. Results: There were 24 subjects with 25 repairs in the autograft group and 23 subjects with 25 repairs in the allograft group. Motor recovery of ≥M3 was achieved in 64% and ≥M4 in 28% of autograft repairs. In contrast, motor recovery of ≥M3 was achieved in 80.0% and ≥M4 in 60% of allograft repairs. The median (interquartile range) MRCC score in the autograft cohort was 3.0 (1.0-4.0; 95% CI, 2.0-3.0) and 4.0 (3.0-4.0; 95% CI, 3.0-4.0) in the allograft cohort. The mean (SD) MRCC score in the autograft cohort was 2.5 (1.5; 95% CI, 1.9-3.1) and 3.2 (1.4, 95% CI, 2.7-3.8) in the allograft cohort. Analysis found that return of motor function in nerve allograft was as favorable as autograft. Conclusions: These findings support allograft as a reasonable alternative to autograft for upper extremity mixed and motor nerve transection injuries. Allograft performed as favorable as autograft while avoiding the need for autograft harvest and the potential donor site morbidity. Type of study/level of evidence: Therapeutic III.