The necessity of anterior transposition of the ulnar nerve in patients receiving corrective osteotomy for cubitus valgus deformity with tardy ulnar nerve palsy: A prospective comparative observational study

Background: Cubitus valgus deformity is a condition that is often treated with supracondylar corrective osteotomy. Meanwhile, tardy ulnar nerve palsy requires an anterior transposition of the ulnar nerve. This is the most common and preferred procedure. However, there is a lack of research on using a combined approach to deal with both cubitus valgus deformity and tardy ulnar nerve palsy. Objectives: The purpose of this study was to establish if anterior transposition of the ulnar nerve is necessary in patients with medial closed-wedge osteotomy for cubitus valgus deformity with tardy ulnar nerve palsy. Methods: This cross-sectional study involved two groups of patients. In the first group, a closed wedge osteotomy was performed without nerve transposition. In the second group, a closed wedged osteotomy was performed with anterior transposition of the ulnar nerve. Results: The two-point discrimination test was conducted on two groups of patients, group ۱ and group ۲, both before and after surgery. The mean pre-operative two-point discrimination for group ۱ was ۵.۶, which improved to ۳.۸ post-operatively. Similarly, the mean pre-operative two-point discrimination for group ۲ was ۷.۵, which improved to ۴.۰ post-operatively. The mean Disabilities of the Arm, Shoulder and Hand (DASH) score for both groups improved significantly after surgery. For group ۱, it improved from ۲۸.۸ (pre-operative) to ۱۵.۶ (post-operative). For group ۲, it improved from ۳۲.۵ (pre-operative) to ۱۶.۲ (post-operative). The mean Humerus Elbow Wrist (HEW) angle, which is a measure of joint deformity correction, was also improved in both groups after surgery. For group ۱, it improved from ۳۵.۸ (pre-operative) to ۱۱.۴ (post-operative), and for group ۲, it improved from ۳۷.۲ (pre-operative) to ۱۲.۰ (post-operative). The range of motion (ROM) angle was also measured before and after surgery. The mean pre-operative ROM angle was ۱۱۵ for group ۱ and ۱۱۲.۵ for group ۲. The mean post-operative ROM angle was ۱۱۹ for group ۱ and ۱۱۷.۵ for group ۲. Overall, the functional outcome and deformity correction were excellent in all patients in both groups. Conclusion: It has been found that treating cubitus valgus deformity with a medial closed wedge osteotomy relieves tension on the tethered ulnar nerve. There seems to be no need for anterior transposition of the ulnar nerve to recover from tardy ulnar nerve palsy. Additionally, there is very little chance of an accidental nerve injury during the procedure.

Keywords:

Cubitus valgus , Ulnar nerve palsy , Anterior transposition , Osteotomy