Median nerve compression complicating arthrodesis of the rheumatoid wrist

The frequency and pathogenesis of median nerve compression complicating the Rush pin method of fusing the rheumatoid wrist was evaluated retrospectively. This complication was encountered in 14/50 wrists (28%). In 7 hands the carpal tunnel was explored, mostly within 2 weeks after fusion. In addition to signs of acute entrapment of the median nerve the most constant finding was that the volar edge of the resected distal end of the radius was prominent and projected into the bottom of the carpal tunnel caused by too vigorous correction of the subluxed carpus. Obviously the median nerve was squeezed or angulated at the volar edge of the radius. After median nerve release and resection of the bony prominence all patients regained full sensibility within the period of observation (in average 2.5 years). It is concluded that this mechanism of nerve entrapment should be realized when fusion of a severely destructed rheumatoid wrist is considered.