Predictors of the patient-centered outcomes of surgical carpal tunnel release – a prospective cohort study

BACKGROUND: Carpal tunnel syndrome (CTS) causes a substantial burden of disease in society. While CTS can be resolved by surgical carpal tunnel release, it still remains unclear as to what degree outcomes depend on patients’ characteristics. This study assesses patient-centered outcomes after surgical carpal tunnel release in a large outpatient clinic in Germany. METHODS: Patients with CTS were recruited prospectively between August 1(st) and December 31(st), 2013. We assessed socio-demographic and psychological factors as well as nerve conduction velocities at baseline (before the surgery) and at three and six months after surgery. We analyzed the improvement of patient-centered outcomes (symptoms and function of the affected hand as well as measures of well-being and subjective quality of life) at the two follow-up time points and investigated if socio-demographic characteristics and CTS-related variables predict the success of the surgery with respect to nerve conduction velocities and patient-centered outcomes by means of analysis of covariance (ANCOVA). Factors influencing the duration of sick leave were investigated by means of Cox regression. RESULTS: The study sample consisted of 71 CTS cases. Surgical carpal tunnel release generally improved nerve conduction velocity and patient-centered outcomes. Regarding the former, the improvement was proportional to the severity score at baseline. The presence of muscular atrophy in the thenar area at baseline displayed medium size effects for the patient-centered outcomes. Other socio-demographic characteristics and CTS-related variables did not have a strong predictive effect on the improvement of nerve conduction velocity and patient-centered outcomes. CONCLUSIONS: There is a significant improvement of clinical and subjective outcomes after CTS surgery in the outpatient sector. The improvement is largely independent of socio-demographic and clinical characteristics of the patients.