Complete endoscopic carpal canal decompression.

We made a model of the endoscopic decompression of the carpal canal in clinical cases. The model entailed the release of the transverse carpal ligament, ie, the flexor retinaculum, first; then the transverse fibers: deep layer of the midpalmar fascia or distal portion of the flexor retinaculum; and, finally, release of the forearm fascia. Carpal canal pressure was measured using the continuous infusion technique, and the carpal canal was observed endoscopically at each step. Carpal canal pressure data were analyzed by using the Wilcoxon matched pairs signed-rank test. When the transverse carpal ligament and the transverse fibers were divided, carpal canal pressure was significantly statistically lower than that with release of the transverse carpal ligament alone. We conclude that release of both the transverse carpal ligament and the transverse fibers are essential for complete decompression of the carpal canal in endoscopic surgery.