A comparison of outcomes of triceps motor branch-to-axillary nerve transfer or sural nerve interpositional grafting for isolated axillary nerve injury

Background: Deltoid paralysis following isolated axillary nerve injury can be managed with triceps motor branch transfer or interpositional grafting. No consensus exists on the treatment that results in superior deltoid function. The purpose of this study was to review the authors' experience with axillary nerve injury management and compare functional outcomes following these two treatment options. Methods: Twenty-nine adult isolated axillary nerve injury patients that had either interpositional nerve grafting or triceps motor branch transfer with greater than 1 year of follow-up between 2002 and 2013 were reviewed for demographic and clinical factors and functional outcomes of deltoid reinnervation, including clinical examination (shoulder abduction and forward flexion graded by the Medical Research Council system) and electromyographic recovery. Disabilities of the Arm, Shoulder, and Hand scale grades were also compared. Results: Twenty-one patients had a triceps motor transfer and eight had interpositional nerve grafting. At a mean follow-up of 22 months, Medical Research Council scores were greater in the grafting group compared with the nerve transfer group (4.3 versus 3.0), and more graft patients achieved useful deltoid function (Medical Research Council score ≥3) recovery (100 percent versus 62 percent); however, both groups had similar improvement in self-reported disability: change in Disabilities of the Arm, Shoulder, and Hand score of 11 following nerve transfer versus 15 following nerve graft. Conclusions: Although the question of nerve transfer versus grafting for restoration of axillary nerve function is controversial, this study demonstrates that grafting can result in good objective functional outcomes, particularly during an earlier time course after injury. This question requires further investigation in a larger, prospective patient population.