Injury to the Distal Motor Branch of the Ulnar Nerve From Thumb K-Wire Fixation

Abstract

We present a complication of trapeziectomy with hematoma distraction arthroplasty for thumb carpometacarpal joint arthritis in a 61-year-old female. Shortly after Kirschner (K)-wire removal at 5.5 weeks post-operatively, the patient noted weakness with thumb adduction. Electromyography and nerve conduction studies done at 3, 5, and 14 months post-operatively showed acute axonal ulnar neuropathy affecting the deep, distal motor branch of the left hand with subsequent partial recovery of function. We postulate that insertion of 1 of the 2 K-wires resulted in a third-degree transection injury to the deep motor branch of the ulnar nerve. To our knowledge, this complication has not been previously reported. We believe it is important for surgeons performing this procedure to be aware of this potential complication as it results in a significant functional disability for the patient.