Histopathological, clinical, and electrophysiological features influencing postoperative outcomes in carpal tunnel syndrome.

Data on the outcome predictors of surgical result of carpal tunnel syndrome (CTS) is sparse and often conflicting. The purpose of this prospective comparative study was to evaluate the neurophysiologic findings and histological characteristics of the flexor tenosynovium in patients with CTS, assessing possible associations between these findings and preoperative patient status or surgical outcome. We evaluated 30 consecutive patients with a diagnosis of idiopathic CTS who were referred for surgery. Demographic data, subjective and objective data, and responses on an expanded assessment set, were collected before and 6 months after surgery. All patients underwent diagnostic neurophysiological testing prior to surgery, and histological analysis of tenosynovium specimens that were removed during surgery. Ten fresh-frozen cadavers served as controls. There was significant improvement in most of the disease specific (Boston questionnaire and Hi-Ob scale) and health generic (SF-36 questionnaire) evaluation tools used in the study at the 6-month follow-up. Vascular changes were noted in the tenosynovium of the flexor tendon of patients with CTS when compared with controls. Greater synovial vascularization was negative predictor of the SF-36's physical summary score before surgery. Bilateral presentation of symptoms and low nerve conduction velocity were negative predictors of the quality of life of patients after surgery for CTS. These findings have to be considered when discussing with patients as for the expected and desired outcomes of CTS surgery. The increased vascularization of flexor tenosynovium is associated with patients' functional status.