Effects of metabolic syndrome on the outcome of carpal tunnel release: A matched case-control study

Purpose To compare outcomes of carpal tunnel release in patients with or without metabolic syndrome. Methods In a prospective consecutive series, 35 patients with metabolic syndrome and surgically treated carpal tunnel syndrome (CTS) were age- and sex- matched with 37 control patients without metabolic syndrome. Grip, pinch strength, perception of touch with Semmes-Weinstein monofilament, and Boston Carpal Tunnel Questionnaires (BCTQ) were assessed preoperatively and at 3, 6, and 12 months postoperatively. Results Patients with metabolic syndrome had more severe electrophysiologic grade of CTS than those without metabolic syndrome, but the 2 groups had similar preoperative grip/pinch strength and BCTQ scores. The BCTQ symptom score for the metabolic syndrome group was significantly greater than that of the control group at 3 months, and the BCTQ function score of the metabolic syndrome group was significantly greater than that of the control group at 3 and 6 months' follow-up. However, there was no significant difference in BCTQ symptom or functional scores between groups at 12 months' follow-up. There was no significant difference in grip strength between groups through 12 months' follow-up whereas the pinch strength of the control group was significantly greater than that of the metabolic syndrome group at 12 months' follow-up. Semmes-Weinstein monofilament test results were significantly greater in the control group than in the metabolic syndrome group at 3 and 6 months' follow-up but were similar at 12 months. Conclusions Patients with CTS and metabolic syndrome have delayed functional recovery after carpal tunnel release, but noteworthy improvements in symptom severity and hand function are similar to those in patients without metabolic syndrome 1 year after surgery. Type of study/level of evidence Prognostic II.