Reflex sympathetic dystrophy following total knee replacement.

Twenty-nine patients who eventually had a diagnosis of reflex sympathetic dystrophy (RSD) following total knee replacement were treated with lumbar sympathetic blocks with local anesthetic. The diagnosis was made based on the complaint of constant pain unrelated to physical activity in the absence of overt sepsis or implant loosening. In six of these cases, other factors may have clouded the diagnosis. Thirteen (44.8%) patients obtained complete relief following an average of 1.8 blocks. Three of these patients had symptoms for more than two years. Twelve patients had complete or partial relief for varying periods of time, but the relief was not sustained. Three obtained no relief at all, and in one the block could not be successfully carried out. This success rate, while shedding no light on the etiology or diagnostic accuracy, has encouraged the authors to continue with this method of treatment in such cases.