Complete dislocation of the ulnar nerve at the elbow: A protective effect against neuropathy?

Introduction: Recurrent complete ulnar nerve dislocation has been perceived as a risk factor for development of ulnar neuropathy at the elbow (UNE). However, the role of dislocation in the pathogenesis of UNE remains uncertain. Methods: We studied 133 patients with complete ulnar nerve dislocation to determine whether this condition is a risk factor for UNE. In all, the nerve was palpated as it rolled over the medial epicondyle during elbow flexion. Results: Of 56 elbows with unilateral dislocation, UNE localized contralaterally in 17 elbows (30.4%) and ipsilaterally in 10 elbows (17.9%). Of 154 elbows with bilateral dislocation, 26 had UNE (16.9%). Complete dislocation decreased the odds of having UNE by 44% (odds ratio=0.475; P= 0.028), and was associated with less severe UNE (P=0.045). Conclusions: UNE occurs less frequently and is less severe on the side of complete dislocation. Complete dislocation may have a protective effect on the ulnar nerve.