Minimally invasive modified Camitz opponensplasty for severe carpal tunnel syndrome

Purpose: We aimed to compare the clinical results and the complications between the minimally invasive modified Camitz opponensplasty and the conventional Camitz opponensplasty for severe carpal tunnel syndrome (CTS), and to evaluate the efficacy of the modified technique for CTS. Methods: Twenty-eight hands in 24 patients with severe CTS who had disorder of the thumb opposition with thenar muscle atrophy (group 1) were treated by minimally invasive modified Camitz opponensplasty, passing the transferred palmaris longus (PL) tendon under the abductor pollicis brevis (APB) fascia using only palm and thumb incision, and no incision to either wrist crease or forearm. Ten hands in 10 patients (group 2) were treated by the conventional Camitz opponensplasty. Clinical evaluation was made by comparing the results before and after surgery for the angle of the thumb palmar abduction, pinch power, and grip strength. Results: All clinical findings significantly improved after surgery compared with before surgery in all patients. In group 1, there were no complications including transferred tendon bowstring, painful wrist scar, or injury to the palmar cutaneous branch of the median nerve in all hands. Conversely, patients in group 2 had four painful wrist scars and nine bowstrings of the transferred tendon. Conclusions: Several complications have been considered to attribute to the long incision and an extensive dissection crossing the wrist crease from the palm to the wrist in the conventional Camitz procedure. The current modified Camitz opponensplasty by minimally invasive incision without straddling the wrist crease is a simple and effective procedure that can decrease the risk of painful scar around the wrist crease in severe CTS patients with disorder of thumb opposition. Additionally, this technique, by passing the transferred PL tendon under the APB fascia, is useful in restoring the thumb opposition immediately, and in preventing the bowstringing of the transferred tendon.