EFFECTS OF ENDOSCOPIC RELEASE OF THE TRANSVERSE CARNAL LIGAMENT ON CARPAL CANAL VOLUME

Ten hands in 10 patients with carpal tunnel syndrome were treated by s ubcutaneous transverse carpal ligament release using the Universal Sub cutaneous Endoscope system. We analyzed the morphologic changes of the carpal canal with magnetic resonance imaging (0.064 T) before and aft er the operation. The axial plane, which includes the beak of the trap ezium and the hook of the hamate, was selected for analysis. The soft tissue boundaries of the carpal canal were outlined at the plane. The cross-sectional area of the carpal canal was 232 +/- 49 mm(2) before s urgery and 320 +/- 108 mm(2) after surgery. There was a 33% +/- 15% in crease of the carpal canal cross-section after transverse carpal ligam ent release. The transverse carpal ligament became more outwardly conv ex after the operation. The endoscopic procedure is effective for incr easing the cross-sectional area and volume of the carpal canal.