Elbow flexion after upper brachial plexus injury may be restored by a nerve transfer from the ulnar nerve to the biceps motor branch with an optional nerve transfer from the median nerve to the brachialis motor branch (single and double fascicular nerve transfer). This meta-analysis assesses the effectiveness of both techniques and the added value of additional reinnervation of the brachialis muscle.
Comprehensive searches were performed identifying studies concerning restoration of elbow flexion through single and double fascicular nerve transfers. Only C5-C6 lesion patients were included in quantitative analysis to prevent confounding by indication. Primary outcome was the proportion of patients reaching British Medical Research Council (BMRC) elbow flexion grade ≥ 3. Meta-analysis was performed with random effect models (REM).
A total of 35 studies were included (n=688). In quantitative analysis 29 studies were included (n=341). After single fascicular nerve transfer 190/207 patients (REM: 95.6%; 95%CI: 92.9-98.2) and after double fascicular nerve transfer 128/134 patients reached MRC≥3 (REM: 97.5%; 95%CI: 95.0-100) (P=0.301). Significantly more double nerve transfer patients reached MRC≥4 if pre-operative delay was ≤ 6 months (84/101 vs. 49/51; p=0.035).
Additional reinnervation of the brachialis muscle did not result in a significantly more patients reaching MRC≥3 elbow flexion. Double fascicular nerve transfer may result in more patients reaching MRC≥4 in patients with a pre-operative delay under 6 months. The median nerve may be preserved or used for another nerve transfer without substantially impairing elbow flexion restoration.
1. Department of Plastic, Reconstructive and Hand Surgery, Erasmus Medical Center, ‘s Gravendijkwal 230, 3015 CE Rotterdam, the Netherlands. Phone: +31 10-704-0704
2. Department of Orthopedic Surgery, Division of Hand Surgery, Mayo Clinic, 200 First Street Southwest, Rochester, MN 55905, USA. Phone: +1 507-284-0475
3. Xpert Clinic, Hand and Wrist Surgery, Jan Leentvaarlaan 14-24, 3065 DC Rotterdam, The Netherlands
Acknowledgements: We would like to thank Wichor Bramer, biomedical information specialist of the medical library in the Erasmus Medical Center, for his expert assistance with the systematic literature search. We would like to thank Grigorios Papageorgiou for his expert assistance with the meta-analysis.
Conflict of interest: The authors declare no conflict of interest related to the submitted work.
Author contributions: All authors contributed to the conception and design of this study. DS, LFB, CAH, and WJT, contributed to literature screening, data collection and interpretation and drafting and revision of the manuscript. SERH and AYS contributed to the data interpretation and provided critical revisions of the manuscript. All authors gave final approval of the submitted manuscript.
Corresponding Author: Alexander Y. Shin, M.D., Professor and Consultant of Orthopedic Surgery, Mayo Clinic, 200 1st St. SW, Rochester, MN, 55905. Phone: 507-284-0475, Fax: 507-284-5539, Email: email@example.com