A new technique for endoscopic carpal tunnel decompression.

A new one-portal technique for endoscopic carpal tunnel release (ECTR) is introduced with its clinical results. The incision is made at the palmar aspect of the hand. A custom-made glass tube with a groove is inserted, and under endoscope observation, a meniscus knife is pushed forward along the groove to release the flexor retinaculum. This new technique has been studied in ten fresh cadaver hands and used in 123 patients' hands. Results of the cadaver study showed that the flexor retinaculum was released completely in all ten hands. No injuries to tendons, nerves, or arteries were noted. In one case the cotton tip was lost from the stick. All clinical releases were performed uneventfully except for three cases of neuropraxia of the digital nerve of the radial side of the ring finger, one laceration of the motor branch of the median nerve, one mild infection, one loss of cotton tip from the cotton swab stick, and one case of chipping of the glass tube. The case with the laceration of the motor branch of the median nerve occurred early in the series and required the conventional open incision to repair the nerve. The cases with loss of cotton from the stick and chipping of the tube also required a conventional incision to remove the cotton and glass chip. Advantages of this one-portal technique with the glass tube include less scar tenderness than with two-portal techniques, decreased risk of injury to the superficial palmar arch and ulnar nerve because of the distal approach, a view of pathology in the carpal tunnel through the glass tube, and confirmation of release of the flexor retinaculum.