Longer distal motor latency predicts better outcomes of carpal tunnel release.

The association of preoperative median nerve distal latencies with surgical outcomes of carpal tunnel release is unclear. A total of 109 surgically treated workers with carpal tunnel syndrome across the state of Maine completed questionnaires assessing preoperative levels of symptom and functional limitations and general physical health (SF-12). A second questionnaire assessed the 6-month postoperative outcomes of symptom severity, functional limitations, and satisfaction with surgery. Univariate analyses indicated that longer preoperative distal motor and sensory latencies were associated with less postoperative levels of symptom, less postoperative functional limitations, and more satisfaction with surgery. The associations persisted in multiple linear regression analysis; however, better general health preoperatively was a better predictor of favorable outcomes. The results suggest that workers with prolonged preoperative distal motor latencies and who are in good general health preoperatively have a higher rate of successful carpal tunnel release surgery.