Objective: To identify factors that are predictive of the outcomes of greatest importance to patients-i.e., symptom relief, functional improvement, and satisfaction with the outcomes of surgery-following carpal tunnel release.
Methods: We analyzed data from the Maine Carpal Tunnel Study, a community-based study of the outcomes of treatment for carpal tunnel syndrome. In a cohort of patients who underwent carpal tunnel release, a preoperative physical examination was performed and questionnaires were completed preoperatively and at 6, 18, and 30 months postoperatively. The questionnaires assessed symptom severity, upper extremity functional limitations, mental health, general physical health status, the relative severity of individual symptoms, satisfaction with the results of surgery, sociodemographic factors, and for those subjects who were in the workforce, aspects of the work environment. The associations between preoperative factors and the 3 principal outcomes (symptom severity, upper extremity functional limitations, and satisfaction with the results of surgery, all evaluated at 18 months postoperatively) were assessed with bivariate and multivariate linear regression and logistic regression analyses.
Results: Two hundred forty-one subjects were enrolled and 188 (78%) completed followup surveys 18 months postoperatively. Two-thirds of the patients reported being completely or very satisfied with the outcomes of surgery at 6, 18, and 30 months postoperatively. A range of clinical and work-related variables were associated with outcomes. In multivariate analyses, greater preoperative upper extremity functional limitation was predictive of greater functional limitations postoperatively. Worse mental health status was significantly associated with more severe symptoms and lower satisfaction. Alcohol use was also associated with more severe symptoms and lower satisfaction. Among workers, involvement of an attorney was significantly associated with greater functional limitation, more severe symptoms, and lower satisfaction. Recipients of worker's compensation who did not hire an attorney had generally good outcomes. Of note, physical examination parameters were not predictive of the outcomes of surgery.
Conclusion: The outcomes of carpal tunnel release in community-based practices are excellent. Predictors of the outcomes of surgery are disease-specific and generic clinical factors as well as work-related factors. The strongest predictors of less favorable outcomes are worse scores on patient-reported measures of upper extremity functional limitation and mental health status, alcohol use, and the involvement of an attorney. Clinicians should carefully evaluate patients' functional status, mental health status, health habits, and attorney involvement prior to performing carpal tunnel release, and discuss with patients the prognostic implications of these parameters.