Time Course of Elbow Flexion Recovery Following Brachial Plexus Injury and Peripheral Nerve Reconstruction

BACKGROUND AND OBJECTIVES: Brachial plexus injuries (BPI) result in severe sensory and motor deficits of the arm, including partial or complete loss of function in the limb. This retrospective cohort study aimed to assess clinical outcomes and specifically the time course of elbow flexion (EF) recovery following injury and reconstruction after BPI. METHODS: This study included patients who had a BPI with an EF deficit between 2016 and 2024. Medical records were reviewed retrospectively, collecting data on patient demographics, treatment, EF strength, and electromyography data. Analyses were performed to establish a clinical threshold of recovery and create models to better predict recovery. RESULTS: This study included 54 patients, 39 (72%) of whom received a surgical intervention. These included Oberlin-type, intercostal, phrenic nerve transfers; nerve grafts of the plexus; and free functional muscle transplants. 15 patients (28%) were managed without surgical intervention. Patients who functionally and neurophysiologically recovered reached functional EF recovery (Medical Research Council Scale for Muscle Strength ≥3) in a median of 8.30 months, and neurophysiological (electromyography) recovery (≥3 biceps motor units) in a median of 6.80 months. Neurophysiological recovery preceded functional recovery by a median of 3.65 months and was a significant predictor of functional recovery ( P = .006). Time point analysis revealed that 5 months postinjury or postintervention is a critical time for predicting recovery. CONCLUSION: In this retrospective study of patients with BPI and EF deficits, longitudinal data such as EF Medical Research Council Scale for Muscle Strength and biceps electromyographies are useful clinical predictors for recovery. Although the treatment of BPI remains highly individualized, these data suggest 2 key metrics, neurophysiological recovery and the 5-month benchmark, to better counsel patients on the time course of their recovery. Importantly, different injury types and reconstructions did recover at different rates, and this must be taken into consideration when attempting to predict ultimate recovery or need for reconstruction.