Comparative Outcomes of Revision Carpal Tunnel Release with External Neurolysis versus Primary Carpal Tunnel Release: A Propensity-Matched Study

Abstract

Background: Carpal tunnel syndrome (CTS) is a common neuropathy of the upper limb, with carpal tunnel release (CTR) being a widely performed surgical intervention when conservative treatments fail. However, up to 20% of patients experience persistent or recurrent symptoms, and up to 12% may require revision surgery. This study aims to evaluate the outcomes of revision CTR with external neurolysis compared to primary CTR using propensity score matching (PSM). Methods: This retrospective single-centre cohort study included patients who underwent primary and revision CTR between March 2021 and February 2024. A total of 38 patients were analysed, with 19 patients undergoing revision CTR (Group 1) and 19 patients undergoing primary CTR (Group 2). PSM (1:1 nearest-neighbour, calliper 0.2) was used to ensure comparability between the groups based on age, weight, height, body mass index (BMI), comorbidities and the operated arm. Clinical outcomes were assessed using the Visual Analogue Scale (VAS) for pain and the Boston Carpal Tunnel Questionnaire (BCTQ) for symptom severity and functional status. Results: Patients in Group 1 initially presented with significantly higher VAS scores compared to Group 2 (8.1 vs. 6.5, p = 0.001). At an average follow-up of 13.9 months, the BCTQ scores for symptom severity scale (SSS) and functional status scale (FSS) in Group 1 were comparable to those in Group 2 (SSS: 16.0 vs. 17.4, p = 0.393; FSS: 12.2 vs. 14.9, p = 0.101). No significant differences in CTS severity grades on electrodiagnostic studies were observed between the groups preoperatively. One patient in Group 1 experienced symptom recurrence 18 months postoperatively, but no other complications were reported. Conclusions: Revision CTR with external neurolysis can effectively manage persistent or recurrent CTS, though patients may require a longer recovery period to achieve outcomes similar to those undergoing primary CTR.