The potential benefit of intracarpal pressure measurement in endoscopic carpal tunnel syndrome surgery--an analysis of EMG findings and pressure values.

Endoscopic carpal tunnel syndrome surgery is a modern minimally invasive method of carpal tunnel decompression. However, the method does also have its critics, who emphasize that there is an increased rate of complications in comparison to open procedures. To further improve and optimize results of endoscopic surgery we used an intracarpal pressure sensor to verify the effect of carpal tunnel decompression. The endoscopic single portal approach was used in all cases. Median nerve conduction studies were performed prior to and 3 months after surgery. Two groups, those with pressure studies and those without, were then compared according to several EMG parameters such as: median nerve distal motor latency, amplitude of motor response, sensory nerve conduction velocity to the index finger, and amplitude of sensory nerve action potential. In both groups, we observed similarly significant improvements in all conduction parameters, except the amplitude of motor response, which did not change in either group, i.e. no difference in postoperative EMG between the two groups was observed. Despite this fact, intracarpal pressure measurement is still useful in localising the point in which the median nerve is compressed and provides valuable functional information on the level decompression achieved.