Nerve Reconstruction Using Processed Nerve Allograft in the U.S. Military

Background: Processed nerve allograft (PNA) is an alternative to autograft for the reconstruction of peripheral nerves. We hypothesize that peripheral nerve repair with PNA in a military population will have a low rate of meaningful recovery (M ≥ 3) because of the frequency of blasting mechanisms and large zones of injury.

Methods: A retrospective review of the military Registry of Avance Nerve Graft Evaluating Utilization and Outcomes for the Reconstruction of Peripheral Nerve Discontinuities database was conducted at the Walter Reed Peripheral Nerve Consortium. All adult active duty military patients who underwent any peripheral nerve repair with PNA for complete nerve injuries augmented with PNA visit were included. Motor strength and sensory function were reported as a consensus from the multidisciplinary Peripheral Nerve Consortium. Motor and sensory testing was conducted in accordance with the British Medical Research Council.

Results: A total of 23 service members with 25 nerve injuries (3 sensory and 22 mixed motor/sensory) underwent reconstruction with PNA. The average age was 30 years and the majority were male (96%). The most common injury was to the sciatic nerve (28%) from a complex mechanism (gunshot, blast, compression, and avulsion). The average defect was 77 mm. Twenty-four percent of patients achieved a meaningful motor recovery. Longer follow-up was correlated with improved postoperative motor function (r = 0.49 and P = .03).

Conclusions: The military population had complex injuries with large nerve gaps. Despite the low rate of meaningful recovery (27.3%), large gaps in motor and mixed motor/sensory nerves are difficult to treat, and further research is needed to determine if autograft would achieve superior results.

Type of study/level of evidence: Therapeutic, Level III.