Double Fascial Flap Stabilization for Ulnar Nerve Instability After In Situ Decompression

Abstract

Purpose: To assess the outcomes of double fascial flap stabilization in managing ulnar nerve subluxation after a simple decompression procedure for cubital tunnel syndrome. Methods: We conducted a retrospective review of 20 patients who experienced ulnar nerve subluxation after simple decompression and were treated with double fascial flap stabilization between 2016 and 2018. Fascial flaps were harvested from the flexor carpi ulnaris and the septum between the triceps and biceps. Patients were classified using McGowan criteria and outcomes were measured using the visual analog scale, grip strength, and the criteria of Messina and Messina for recovery. In addition, we assessed ulnar nerve instability after in situ decompression in 10 fresh cadavers. Tang’s grading and measuring system was used to measure ulnar instability. Results: There were 13 excellent and 7 good outcomes (65% and 35%, respectively). Mean follow-up duration was 9.1 months (range, 3–23 months). Mean visual analog scale scores improved significantly from 5.8 before to 1.3 after surgery. Mean Quick–Disabilities of the Arm, Shoulder, and Hand scores improved significantly from 37.9 before to 10.9 after surgery. Mean grip strength compared with the contralateral side improved significantly from 73.9% before to 89.6% after surgery. Anatomic cadaveric dissection revealed that 6 of 10 cadavers (60%) met the criterion of moderate to severe ulnar nerve instability. Conclusions: Double fascial flap stabilization with simple decompression resulted in excellent short-term clinical results. This technique provides an alternative strategy to prevent ulnar nerve instability with the advantage of preserving nerve vascularity. Long-term follow-up is required to evaluate the potential impact on recurrence or failure of simple decompression. Type of study/level of evidence: Therapeutic IV. Key words: anterior transposition, cubital tunnel syndrome, fascial flap, in situ decompression, ulnar nerve dislocation