Chemonucleolysis: evaluation of effectiveness by electromyography

Findings in 97 consecutive patients who had undergone chemonucleolysis were analyzed. The purpose of this prospective clinical study was two-fold: (1) to provide a comparison of preoperative findings of electromyography, myelography and discography and (2) to evaluate postoperative electromyography as an objective test of recovery. All the patients had complete history and physical examination, five-view roentgenographic study of the lumbosacral spine, electromyography preoperatively and again at three months postoperatively, myelography and discography. Computer analysis of the results was done for the multiple cross-correlations in the study. All patients had had at least three months preoperative conservative care without relief of symptoms. The study shows that electromyographic study three months postchemonucleolysis is of value for corroboration of clinical improvement only if the EMG becomes completely normal. A greater percentage of patients recovered clinically after chemonucleolysis when the preoperative EMG was normal as compared to those for whom the preoperative EMG was abnormal. We were surprised to find no significant correlation between end result and the existence of pending litigation.