Submuscular transposition of the ulnar nerve for persistent or recurrent cubital tunnel syndrome: Results of a prospective case series.

Background: Submuscular transposition (SMT) of the ulnar nerve is frequently performed as secondary procedure in patients with persistent or recurrent cubital tunnel syndrome (CuTS) despite previous surgery. Good results have been reported for this surgical strategy, but mainly in small retrospective case series. The goal of the present study is therefore to analyze the results prospectively using a patient-reported outcome measure (PROM): patient-rated ulnar nerve evaluation (PRUNE).

Methods: SMT of the ulnar nerve was performed in 30 consecutive patients who were referred because of persistent or recurrent CuTS despite previous surgery. Objective outcome was measured in the outpatient clinic using the Likert scale. The PRUNE questionnaire was obtained pre-operatively, 6 weeks, 3 months, 6 months, and 12 months after the surgery. Simultaneously, 20 patients with primary surgery for CuTS, that underwent simple decompression, were followed.

Results: Good outcome (Likert 1 or 2) was obtained in 67% after SMT for persistent/recurrent CuTS and 85% after decompression as primary surgical treatment. PRUNE scores were significantly decreased in both groups at all follow-up moments after surgery compared with pre-operative for the total questionnaire and subscales "pain," "sensory/motor symptoms," and "specific activities." In both groups, PRUNE score remained stable until 12 months of follow-up.

Conclusion: This prospective study confirms previous results from retrospective studies showing that SMT is an effective surgical option for persistent or recurrent CuTS. Prospective (randomized controlled) trials are needed to compare the effectiveness of SMT to the surgical alternative of subcutaneous transposition of the ulnar nerve.