[Intraoperative pressure measurement at the median nerve in carpal tunnel syndrome and its surgical significance]. / Intraoperative Druckmessung am N. medianus beim Karpaltunnelsyndrom und deren operative Bedeutung.

The authors measured the intraoperative pressures on the median nerve in local anesthesia in thirty patients. Pressures were recorded at the distal antebrachial fascia near the carpal tunnel, at the proximal and distal carpal tunnel and at the level of the palmar fascia distal to the carpal tunnel. The two passive and three active movements examined generally led to a pressure elevation. Passive movements had a greater effect on pressure at the proximal carpal tunnel. Active movements led to a high pressure level in the proximal and distal carpal tunnel higher than those observed during passive movements. Beneath the distal antebrachial fascia near the carpal tunnel, the pressure level was higher than beneath the antebrachial fascia at a greater distance from the carpal tunnel. Pressure levels beneath the distal antebrachial fascia correlated with the patient's age. Pressure values beneath the palmar fascia were low during passive and active movements. As a consequence, division of the flexor retinaculum and the distal antebrachial fascia up to 3 cm proximal of the carpal tunnel is necessary, whereas dissection of the palmar fascia distal to the carpal tunnel is not.