Supercharged end-to-side anterior interosseous nerve transfer to restore intrinsic function in high ulnar nerve injury: a prospective cohort study.

ABSTRACT

BACKGROUND: High ulnar nerve injuries is known to have unfavorable motor outcomes compared to other peripheral nerve injuries in the upper extremity. Functional muscle recovery after peripheral nerve injury depends on the time to motor end plate reinnervation and the number of motor axons that successfully reach the target muscle. The purpose of this study is to assess the functional recovery, and complications following performing supercharge end-to-side (SETS) anastomosis for proximal ulnar nerve injuries. Our study focuses on the role of SETS in the recovery process of high ulnar nerve injury. PATIENT AND METHODS: This study is a prospective, single-arm, open-label, case series. The original proximal nerve pathology was dealt with according to the cause of injury, then SETS was performed distally. The follow-up period was 18 months. We compared the neurological findings before and after the procedure. A new test was used to show the effect of SETS on recovery by performing a Lidocaine proximal ulnar nerve block test. RESULTS: Recovery of the motor function of the ulnar nerve was evident in 33 (86.8%) patients. The mean time to intrinsic muscle recovery was 6.85 months ± 1.3, only 11.14% of patients restored protective sensation to the palm and finger and 86.8% showed sensory level at the wrist level at the end of the follow-up period. Lidocaine block test was performed on 35 recovered patients and showed no change in intrinsic hand function in 31 patients. CONCLUSION: SETS exhibit a remarkable role in the treatment of high ulnar nerve damage. SETS transfer can act as a nerve transfer that can supply intrinsic muscles by its fibers and allows for proximal nerve regeneration. We believe that this technique improves recovery of hand motor function and allows recovery of sensory fibers when combined with treating the proximal lesion. TRIAL REGISTRATION Approved by Research Ethics Committee of Faculty of Medicine- Cairo University on 01/09/2021 with code number MD-215-2021.