Changes in Cross-sectional Area of the Median Nerve and Boston Carpal Tunnel Questionnaire Scores After Carpal Tunnel Release

Background: We hypothesized that postoperative Boston Carpal Tunnel Questionnaire (BCTQ) scores and ultrasound (US) measurements of the median nerve cross-sectional area (CSA) at the distal wrist crease are significantly decreased at 2-week, 6-week, and ≥ 6 months follow-up appointments, compared with baseline values. Methods: This study was a retrospective chart review of patients who presented to a single hand clinic with evidence of carpal tunnel syndrome over a 6-year period (2014-2020). Patients received baseline US measurements of the median nerve CSA as well as completion of the BCTQ, and for the patients who underwent carpal tunnel release (CTR), postoperative US measurements and questionnaire scores were obtained at 2 weeks, 6 weeks, or ≥ 6 months postoperatively. Results: This study included 224 separate wrists. Median Nerve CSA measurements were 13.2 ± 4.5 mm 2 at baseline, 11.9 ± 3.6 mm 2 at 2 weeks postoperatively, 11.6 ± 4.5 mm 2 at 6 weeks postoperatively, and 11.7 ± 4.3 mm 2 at 6 months or more ( P = .002). The BCTQ Symptom Severity Scale scores were 3.14 ± 0.76 at baseline, 1.76 ± 0.63 at 2 weeks, 1.68 ± 0.70 at 6 weeks, and 1.41 ± 0.64 at 6 months or longer ( P < .001). The BCTQ Functional Status Scale scores were 2.56 ± 0.89 at baseline, 2.03 ± .1.0 at 2 weeks, 1.65 ± 0.77 at 6 weeks, and 1.36 ± 0.61 at 6 months or longer ( P < .001). Conclusions: These findings demonstrated a sustained decrease in median nerve CSA and patient-reported outcomes following CTR at 2 weeks, 6 weeks, and between 6 and 12 months.