Preoperative electrophysiologic testing and intraoperative carpal cana
l pressure measurements were performed on 957 hands in 647 patients wi
th clinical signs of carpal tunnel syndrome. Fifty-five symptomatic ha
nds in 48 patients were normal in both distal sensory latency and dist
al motor latency preoperatively. Carpal canal pressure was, however, s
ignificantly elevated compared to control data in all 55 hands. After
complete subcutaneous release of the carpal canal using the Universal
Subcutaneous Endoscope system, carpal canal pressure was reduced to wi
thin the normal control range. Clinical symptoms of carpal tunnel synd
rome improved in all 55 hands. Postoperative electrophysiologic data r
emained within normal range in patients who agreed to receive electrop
hysiologic examinations.