Outcomes of ulnar nerve anterior transmuscular transposition and significance of ulnar nerve instability in cubital tunnel syndrome

Abstract

We investigated the experience of a single surgeon with ulnar nerve anterior transmuscular transposition with the patient in the lateral decubitus position for cubital tunnel syndrome. The medical records of all patients who underwent primary or revision ulnar nerve anterior transmuscular transposition were screened to define a cohort of 156 patients (162 limbs) for further study of demographic and disease-specific data and retrospective assessment of short-term outcomes. Ulnar neuropathy severity was stratified by McGowan grade. A prospective cohort composed of 49 patients (51 limbs) with a minimum 2-year follow-up volunteered to complete patient outcome surveys, and some presented for an ulnar nerve-focused examination to assess long-term outcomes. The overall patient satisfaction rate was 92%, with statistically significant improvements in ulnar sensation and intrinsic strength at short- and long-term follow-up. Outcomes were better for lower McGowan grades than for higher grades and better in primary cases than in revision cases. Ulnar nerve instability was observed in 69 of 162 cases (43%) in this series. A major complication occurred in 7 cases (4.3%), but all were mitigated by contributory patient-related factors. Reoperation for recurrent ulnar paresthesia was required in 4 cases (2.5%). No operations or outcomes were compromised by the lateral decubitus position. Ulnar nerve anterior transmuscular transposition in the lateral decubitus position is a good surgical option for primary or recurrent cubital tunnel syndrome and remains our preferred procedure. The high prevalence of ulnar nerve instability observed in this study is a factor worthy of consideration by surgeons and patients weighing the surgical options for ulnar neuropathy at the elbow.