Comparative clinical outcomes of submuscular and subcutaneous transposition of the ulnar nerve for cubital tunnel syndrome.

PURPOSE: To determine retrospectively whether the technique of ulnar nerve transposition (subcutaneous versus submuscular) is associated with clinical sensory and motor recovery in cubital tunnel syndrome, and whether recovery is influenced by prognostic factors such as preoperative McGowan stage, age, and duration of symptoms.

METHODS: Twenty-five patients (average age, 53 years; follow-up, 7 years) with cubital tunnel syndrome had submuscular transposition, and 24 patients (average age, 46 years; follow-up, 3 years) were treated by subcutaneous transposition. There were 11 McGowan stage II and 14 stage III patients in the submuscular group and 14 stage II and 10 stage III patients in the subcutaneous group. Preoperatively, all patients presented with diminished 2-point discrimination. Postoperative sensory and motor recovery was evaluated clinically.

RESULTS: There was no significant difference between subjective results in the submuscular and subcutaneous groups: 20 of 25 patients in the submuscular group versus 17 of 24 patients in the subcutaneous group were clearly improved, and 3 of 25 patients in the submuscular group versus 6 of 24 patients in the subcutaneous group partially improved. The logistic multivariate regression analysis indicated that sensory and motor function were both significantly improved following both surgical techniques. Sensory function recovered (2-point discrimination <6 mm) in 17 of 25 patients in the submuscular group and in 17 of 24 patients in the subcutaneous group, and motor function recovered (intrinsic strength grade 5) in 19 of 25 patients in the submuscular group and in 19 of 24 patients in the subcutaneous group. Symptoms lasting more than 6 months were associated with a poor prognosis.

CONCLUSIONS: Sensory and motor recovery for patients with McGowan stages II and III of cubital tunnel syndrome were similar following submuscular and subcutaneous transposition techniques, and patients with symptoms lasting longer than 6 months had a worse prognosis regardless of surgical technique.