Current Gaps and Future Directions in Brachial Plexus, Upper-Extremity and Lower-Extremity Nerve Injuries (Nerve SPACE 2025).

Background: Treatment of peripheral nerve injury remains one of the most challenging aspects of reconstructive surgery. Functional outcomes remain inconsistent, high-quality evidence is limited, and major knowledge gaps persist. Where are we now?: When evaluating patients for peripheral nerve injury, the treating physician must ascertain several critical factors to help inform decision-making, including the timing, mechanism, localization, and severity of the injury. Current algorithms rely on history, physical examination, electrodiagnostic studies, imaging, and occasionally operative exploration to establish a diagnosis. The surgeon must decide if the injury will recover spontaneously or if further operative intervention is indicated to achieve the best possible functional outcome. Accurate prognostication remains challenging secondary to the difficulty grouping patients into homogenous cohorts based on patient and injury characteristics, as well as heterogenous outcome measures. Intraoperatively, determining both the severity and zone of injury remains challenging. Surgical treatment strategies include neurolysis, primary repair, nerve grafting, nerve transfer, or tendon transfers. Functional outcomes assessment is currently performed using Medical Research Council muscle grading, range of motion measures, and various sensory measures, which remain subjective with inconsistent intraobserver and interobserver reliability. Nerve-specific patient reported outcomes measures remain limited. Where do we need to go?: Diagnostic improvements are needed to more quickly and accurately define injury severity and determine which patients will benefit from surgical intervention. Intraoperatively, accurate determination of both the zone of injury and the functional status of the proximal nerve is also needed. Reproducible outcome measures that can be easily adopted across multiple institutions are needed to facilitate high-quality evidence that can help guide treatment decisions. How do we get there?: Multicenter collaborative efforts are needed to focus clinical research priorities using reproducible diagnostic criteria to accurately define injury severity, establish consistency in surgical techniques and treatment algorithms, and accurately and reproducibly measure outcomes. Further translational efforts in imaging, biomaterials, and basic science research are also needed. By aligning research priorities with patient-centered outcomes, the field can begin to close the gap between surgical innovation and functional recovery.