Ulnar nerve entrapment at the wrist: Cases from a hand surgery practice

Background. Eight patients with 11 instances of wrist-level ulnar nerve entrapment, a fairly uncommon compression syndrome, were identified in a hand surgery practice from 1992 through 1996. Methods. Presentations, causes, and surgical outcomes were examined, and the pertinent literature was reviewed. Results. All eight patients had extrinsic, nonidiopathic compression of the ulnar nerve caused by tumor, vascular disease, anomalous muscle development, or a tight fibrous arch at the origin of the flexor digiti minimi. In all cases, sensory symptoms resolved with removal of the cause of ulnar nerve compression. Conclusions. These cases serve to remind physicians that not every instance of numbness and tingling in the hand represents carpal tunnel syndrome. Careful clinical examination may not only localize compression of the ulnar nerve at wrist level but also may reveal its etiology. Some causes of ulnar compressive neuropathy, however, are apparent only with surgical exploration.