Endoscopic Carpal Tunnel Release Using the Biportal Technique

Military Medicine, Feb 2006 by Kahraman, Serdar, Kafadar, Ali, Akb�r�, Murat, Atabey, Cem

The clinical study consisted of 27 patients and 30 hands that were operated on with the biportal endoscopic carpal tunnel release technique between 2000 and 2002. The mean follow-up time was 28 months. The time to return to work or complete recovery was found to average 12 days. The rate of functional recovery was 93% (27 hands), and 90% of hands (26 hands) were free of symptoms at the time of publication. According to our study, we conclude that the biportal endoscopic technique is an effective method to attain patient comfort; it is a minimally invasive method with a low complication rate in experienced hands for surgical treatment of carpal tunnel syndrome. Military persons can return to work quickly, without deficits in hand skills, with the use of this technique.

Introduction

With open carpal tunnel releasing procedures, although relief of symptoms is achieved for a high percentage of patients, scar tenderness and pillar pain may lead to delayed regaining of hand skills. The phenomenon of pillar pain is a frequent complication reported after both open and endoscopie surgical techniques, with incidence rates between 6% and 36%.1,2 It has been characterized as pain or tenderness in the thenar or hypothenar eminence. The cause of pillar pain remains uncertain, but it most commonly originates in the posttriquetral joint, possibly because of alteration of the forces over the joint after releasing of the transverse carpal ligament.3 Pillar pain can delay return to work and resumption of activities of daily living and potentiate loss of grip strength. Endoscopie carpal tunnel release was developed by Chow4 in 1989, as a biportal technique to decrease postoperative morbidity. This technique allows rapid return to normal activities and work, with low complication rates.5 Disadvantages of the endoscopie technique are based mainly on its cost, the difficulty of exploring the carpal tunnel, and higher rates of neurovascular complications in inexperienced hands. In our study, we reviewed data for 27 patients and 30 hands with carpal tunnel syndrome that were treated surgically with the biportal endoscopie method.

Methods

Twenty-seven patients with severe carpal tunnel syndrome were admitted to our clinic between May 2000 and May 2002. AU of them underwent surgery with the biportal endoscopie release technique. The mean age of the four men and 23 women was 43 years (range, 29-73 years). Two of the patients were diabetic. Thirty hands (14 right and 16 left) were operated on by the same surgeon. Four men were heavy manual workers, 18 women were light manual workers, and 5 women were housewives in this study.

The complaints and findings for the patients are summarized in Table I. Predominant postoperative complaints were paresthesia, night pain, and clumsiness. The operation was reserved for patients with pain refractory to medication, severe sensorial deficits, and motor weakness. All patients were diagnosed with electrophysiological studies. Motor weakness was assessed with a dynamometer both preoperatively and postoperatively. Previous surgery was considered a contraindication for the endoscopie technique. All patients had undergone unsuccessful trials of conservative therapy before referral for surgery. If the patient had bilateral carpal tunnel syndrome, then the more symptomatic hand was operated on first.

Chow4 previously described the technique for biportal endoscopie carpal tunnel release. All operations were performed under local anesthesia, without a tourniquet. The wrist was placed in a free position, and an entrance incision was made just medial to the palmaris longus in the proximal transverse crease of the wrist. The antebrachial fascia was opened via blunt dissection, and the proximal edge of the retinaculum flexorum was seen. Then the wrist was positioned in hyperextension. Hyperextension of the wrist significantly displaces the vital structures both dorsally and distally. A curved dissector was introduced via the posterior face of the ligament, remaining in contact with the hook of hamate and avoiding going radially, where a motor branch of the median nerve passing through the retinaculum could be injured. The distal edge and exit incision were determined with the trampoline effect obtained on palpation of the hand. The half-open working channel was inserted into the carpal tunnel, and the bright transverse fibers were recognized with the endoscope. A special half-circle-shaped blade was inserted into the working channel from the proximal entrance, and an endoscope (30� upside) was introduced into the working channel from the distal entrance. The distal edge of the flexor retinaculum was seen with visual control of the endoscope, and the blade was placed under the ligament. Careful slow cutting of the ligament was achieved. Subcutaneous fatty tissue migration into the half-open working channel was seen. This is an important perioperative observation, to achieve complete releasing of the flexor retinaculum. Another important observation is the increased subcutaneous illumination of the endoscope. Hemorrhage after releasing of the flexor retinaculum was not observed except in one case. Entrance and exit incisions were sutured with 5-0 nylon, and compressive dressings were applied. The total time spent for endoscopie releasing was ~10 minutes. All patients were observed for 2 hours after the operation for early postoperative complications. After surgery, every patient was interviewed and examined every month for the existence of preoperative clinical symptoms. At the first check 3 months after surgery, the patients were asked about symptomatic relief and intervals between the operation and return to their daily activities and work and were examined for scar tenderness and aesthetic outcomes. At the same time, all patients were examined electrophysiologically; all patients were then regularly examined every 3 months for functional recovery, with a visual analog scale and a dynamometer.