Low-Velocity Ballistic Trauma–Related Upper Extremity Nerve Injury: A Systematic Review and Meta-Analysis

PURPOSE: Optimal management of upper extremity nerve palsy caused by low-velocity ballistic trauma (LBT) remains controversial. The aim of this systematic review was to summarize the available evidence on the management of nerve injuries caused by LBT to the upper extremity. METHODS: A literature search was completed for the keywords "Upper extremity," "Nerve Injury," and "Ballistic." 2 independent reviewers conducted a systematic screening of all articles and collected data from relevant publications. The data were summarized and pooled using a random-effect model. RESULTS: 14 studies met inclusion criteria. Cohorts between 6 and 168 patients (n = 848) with upper extremity LBT were reported. Neurologic deficits were present in 45% (95% CI: 38 to 52%) of patients at the time of injury evaluation. Nerve exploration was done in 50% (95% CI: 27 to 73%) of these patients with neurologic deficits. Early nerve exploration was done in 19% (95% CI: 9 to 32%) of all patients. Surgical findings included nerve continuity (49%; 95% CI: 14 to 84%), nerve contusion (30%; 95% CI: 12 to 50%), and nerve transection (31%; 95% CI: 14 to 50%). Nerve transection rates found at the time of exploration ranged from 0 to 71% (mean 31%). Outcomes were good in 62% (95% CI: 41 to 81%); however, analyses were limited by subjective outcome reporting of the studies. CONCLUSIONS: Contrary to historical teaching that LBT causes neurapraxia, this review identified that 31% of resulting nerve injuries were neurotmesis (transections). These results advocate for systematic clinical follow-up and appropriately timed nerve intervention (within 3 to 6 months of injury) when neurologic deficits persist after ballistic injury. LEVEL OF EVIDENCE: Level III.