Factors affecting contralateral wrist surgery after one carpal tunnel release in bilateral carpal tunnel syndrome

Carpal tunnel syndrome (CTS) can be bilateral, with varying incidence. Carpal tunnel release (CTR) in one wrist may relieve the symptoms of the contralateral wrist, avoiding the need for second surgery; conversely, the symptoms may persist or worsen, requiring contralateral surgery in some cases. The present study investigated whether surgical treatment was finally required for the non-operated CTS wrist, and in what cases non-operative treatment was possible. We compared baseline characteristics, risk factors and electrodiagnostic data between CTS patients who underwent only unilateral CTR and those who subsequently underwent bilateral surgery at various time intervals. This single-center retrospective study included 188 patients with bilateral CTS managed between 2010 and 2020; 137 patients (group 1, 73%) underwent only unilateral CTR, and 51 (group 2, 27%) subsequently underwent contralateral CTR. In group 1, contralateral CTS symptoms were assessed in 4 categories and compared to the presenting symptoms in the index wrist. There were no significant differences in age, gender, preoperative symptom duration, body status, addictive behavior, electrodiagnostic study or comorbidities, other than a higher rate of dialysis in group 2. The contralateral wrist showed partial or complete symptom relief in 57% of patients undergoing unilateral CTR. High BMI and history of diabetes were risk factors for persistent severe CTS or subsequent contralateral CTR.