Nerve Transfers for Elbow Extension in Tetraplegia: A Case Series

Massachusetts General Hospital

S. Bazarek

Recovery of arm and hand function is considered the highest priority for tetraplegic patients to recover independence. When injuries occur above the C7 neurological level, elbow extension is lost. Without triceps function, the reachable workspace is limited, and patients become entirely dependent when in the supine position. While tendon transfers have been used to restore elbow extension, nerve transfers have recently emerged as a promising alternative with a number of advantages. We present a case series of outcomes for elbow extension recovery using nerve transfer of branches of the axillary nerve to the long head of the triceps branch of the radial via an anterior, trans-axillary approach. Candidates included patients with a traumatic spinal cord injury whose physical examination demonstrated absence of active elbow extension, presence of axillary nerve function, an ASIA motor level 5 – 6, and International Classification of Hand Surgery in Tetraplegia (ICHST) scores of 1-4. Fifteen adult patients (Ages 18-59 years) underwent nerve transfer on 25 limbs with a minimum of 12-month follow-up (2 patients/3 limbs were lost to follow up). The median time from injury to surgery was 9.5 months [Interquartile range 8 - 12]. The primary outcome was MRC strength grade, with a median MRC of 3 [2 - 4)]. The secondary was a satisfaction survey which demonstrated a significant perceived benefit in many patients whose MRC was only 2. Nerve transfer provided satisfactory outcomes in 82% of limbs [MRC 2 or greater], while only 55% achieved true MRC 3 with overhead reach. Patients with a pre-op ICHST score of 3 or 4 all achieved antigravity strength overhead. No deficits from sacrifice of the axillary nerve branches were observed. Further investigation will be necessary to establish predictive factors for success for ICHST scores 1 and 2.