Neural Recovery After Carpal Tunnel Release: A Systematic Review With Meta-Analysis

Abstract

OBJECTIVE: The primary aim was to quantify changes in structural and functional nerve parameters following carpal tunnel release (CTR). The secondary aims were to describe recovery trajectories and describe the regenerative capacity of the median nerve.DESIGN: Prognosis systematic review with meta-analysisLITERATURE SEARCH AND SELECTION CRITERIA: Six databases were searched from inception to June 2024 for studies reporting at least one of the following outcomes: electrodiagnostic measures, quantitative sensory testing, grip/pinch strength, two-point discrimination, Semmes-Weinstein monofilament, intraepidermal nerve fiber density (IENFD), autonomic measures, brain function/structure, or Boston carpal tunnel questionnaire.DATA SYNTHESIS: Outcomes were categorized by time post-surgery: <2, 2–4, 5–7, 8–12, and >12 months. Randomized and observational studies were included, with quality assessed using the RoB 2 tool and the Newcastle–Ottawa Scale, respectively.RESULTS: A total of 199 studies comprising 15,636 patients and 578 healthy controls were included. We observed significant, time-dependent improvement in most outcomes. Grip and pinch strength did not show marked recovery until 5–7 months postoperatively. Compared to healthy controls, patients had persistent deficits in several electrodiagnostic measures even one year after surgery. Impairments in warm, vibration, and mechanical detection thresholds persisted up to 6 months postoperatively.CONCLUSION: CTR led to gradual improvement in median nerve function and structure. Key measures—including electrodiagnostics, detection thresholds, and IENFD—often remained below normal levels after surgery.