Unrecognized dislocation of the medial portion of the triceps: another cause of failed ulnar nerve transposition

Object. Failed surgical treatment for ulnar neuropathy or neuritis due to d islocation of the ulnar nerve presents diagnostic and therapeutic challenge s. The authors of this paper will establish unrecognized dislocation (snapp ing) of the medial portion of the triceps as a preventable cause of failed ulnar nerve transposition. Methods. Fifteen patients had persistent. painful snapping at the medial el bow after ulnar nerve transposition, which had been performed for documente d ulnar nerve dislocation with or without ulnar neuropathy. The snapping wa s caused by a previously unrecognized dislocation of the medial portion of triceps over the medial epicondyle. Seven of the 15 patients also had persi stent ulnar nerve symptoms. The comet diagnosis of snapping triceps was del ayed for an average of 22 months after the initial ulnar nerve transpositio n. An additional surgical procedure was performed in nine of the 15 cases a nd, in part, consisted of lateral transposition or excision of the offendin g snapping medial portion of the triceps. Of the four patients in this grou p who had persistent neurological symptoms, submuscular transposition was p erformed in the two with more severe symptoms and treatment of the triceps alone was performed in the two with milder neurological symptoms. Excellent results were achieved in all surgically treated patients. Six patients dec lined additional surgery and experienced persistent snapping and/or ulnar n erve symptoms. Conclusions. Failure to recognize that dislocation of both the medial porti on of the triceps and the ulnar nerve can exist concurrently may result in persistent snapping, elbow pain, and even ulnar nerve symptoms after a tech nically successful ulnar nerve transposition.