Open versus endoscopic carpal tunnel release: a meta-analysis of randomized controlled trials

Carpal tunnel syndrome is a common compressive neuropathy of the median nerve. The efficacy and safety of endoscopic versus open carpal tunnel release remain controversial.

The purpose of this study was to determine whether endoscopic compared with open carpal tunnel release provides better symptom relief, validated outcome scores, short- and long-term strength, and/or digital sensibility; entails a differential risk of complications such as nerve injury, scar tenderness, pillar pain, and reoperation; allows an earlier return to work; and takes less operative time.

The English-language literature was searched using MEDLINE, the Cumulative Index to Nursing and Allied Health Literature, and the Cochrane Central Register of Controlled Trials. Randomized controlled trials that compared endoscopic and open carpal tunnel release were included in the meta-analysis. Methodologic quality was assessed with the Consolidated Standards Of Reporting Trials (CONSORT) checklist, and a sensitivity analysis was performed. Symptom relief, Boston Carpal Tunnel Questionnaire (BCTQ) scores, strength, digital sensibility, complications, reoperation, interval to return to work, and operative time were analyzed. Twenty-one randomized controlled trials containing 1859 hands were included.

Endoscopically treated patients showed similar symptom relief and BCTQ scores; better early recovery of grip strength (mean difference [MD], 3.03 kg [0.08-5.98]; p = 0.04) and pinch strength (MD, 0.77 kg [0.33-1.22]; p < 0.001) but no advantage after 6 months; lower risk of scar tenderness (risk ratio [RR], 0.53 [0.35-0.82]; p = 0.005); higher risk of nerve injury (RR, 2.84 [1.08-7.46]; p = 0.03), most of which were transient neurapraxias. Similar risk of pillar pain and reoperation; an earlier return to work (MD, -8.73 days [-12.82 to -4.65]; p < 0.001); and reduced operative time (MD, -4.81 minutes [-9.23 to -0.39]; p = 0.03).

High-level evidence from randomized controlled trials indicates that endoscopic release allows earlier return to work and improved strength during the early postoperative period. Results at 6 months or later are similar according to current data except that patients undergoing endoscopic release are at greater risk of nerve injury and lower risk of scar tenderness compared with open release. While endoscopic release may appeal to patients who require an early return to work and activities, surgeons should be cognizant of its elevated incidence of transient nerve injury amid its similar overall efficacy to open carpal tunnel release. Additional research is required to define the learning curve of endoscopic release and clarify the influence of surgeon volume on its safety.