Compression of the median nerve in CTS is mediated by periods of acute synovial swelling.
Tolerance of neural tissue to external compression has been shown to depend on several factors. The mechanism by which acute compression alters peripheral nerve conduction is not completely understood. Ischemic and mechanical factors have alternatively been implicated as the primary causes of nerve dysfunction in compression syndromes. An ischemic etiology for acute nerve compression would be favored if there were changes in pressure within the carpal canal. Upon excision of the synovial tissue from within the canal it has been recognized that the tissue can absorb media and swell to three times it original size. This investigation compares the synovial tissue obtained during carpal tunnel surgeries with synovial tissue collected from control patients presenting with injuries not related to carpal tunnel syndrome. A total of twenty-seven carpal patients and six control patients were included within the study. The synovial tissue was obtained, weighed and placed in a 2 ml of sterile phosphate buffer saline (pH 7.3). The rate of fluid up take was determined at intervals of 15 minutes for the first two hours and then hourly for an additional four hours. The results indicate an increase in fluid uptake ranging between 0.004 mg/min to 0.011 mg/min for the first hour in the CTS patients. The rate of fluid uptake subsides after 4 hours. Control patients exhibited less of an increase in fluid uptake ranging between 0.003 to 0.007 over the first three hours. These differences in fluid retention of the different tissues may suggest a tendency for increased fluid pressure within the carpal canal, which may cause compression of the neural tissues.
Tucci
M
M
University of Mississippi Medical Center, Department of Orthopedic Surgery, Jackson, MS 39216, USA.
Sud
V
V
Freeland
A
A
D000328:Adult; D000368:Aged; D002349:Carpal Tunnel Syndrome / Q000473:pathology / Q000503:physiopathology*; D004487:Edema / Q000473:pathology / Q000503:physiopathology; D005260:Female; D006801:Humans; D066298:In Vitro Techniques; D008297:Male; D008475:Median Nerve / Q000473:pathology*; D008875:Middle Aged; D012965:Sodium Chloride; D013583:Synovial Membrane / Q000473:pathology / Q000503:physiopathology*
D012965:Sodium Chloride