Motor Aberrant Reinnervation Sequelae in Brachial Plexus Birth Injury: Past, Present and Future in 35+ Years Experience
Abstract No:
13198
Additional Author:
David Chuang MD
Abstract Presenting Author:
Jing Qin Tay MBBCh, MRCS, PhD, MBA
Abstract Text:
Background: Muscle co-contraction resulting from motor aberrant reinnervation sequelae (MARS) is a debilitating outcome of brachial plexus birth injury (BPBI), leading to significant shoulder and/or elbow deformities. Surgical management remains controversial with no established consensus on the optimal strategy.
Methods: A retrospective review was conducted on patients treated for BPBI-related MARS between 1986 and 2022. A total of 62 patients with shoulder deformities and 95 patients with elbow deformities were included in the study. Two-thirds of the patients had overlapping deformities. The surgical strategy was based on the hypothesis of aberrant reinnervation syndrome, which involved multiple muscle transpositions to convert antagonists to synergists. The strategy for shoulder deformity was prioritized with shoulder abduction and external rotation restoration by transferring the shoulder adductors to the abductors. The strategy for the elbow deformity was prioritized with the elbow extension restoration by transferring elbow flexors (biceps/ brachialis) to the triceps.
Results: Postoperatively, the mean shoulder abduction improved from 70° to 148° (p<0.001), and the mean external rotation improved from 22° to 72° (p<0.001). For the elbow, the mean extension strength improved from M2 to M3-4 (p<0.0001). While initial elbow flexion strength decreased post-transfer, 78% of patients required second-stage gracilis functioning free muscle transplantation for augmentation, and the end result was successfully maintained at M3 or greater in all patients. Elbow flexion contracture also significantly improved from a mean of 40° to 10° (p=0.0293).
Conclusion: The described surgical strategies by converting antagonists to synergists by multiple muscle transfers are proven effective, durable and long-lasting for treating MARS in BPBI.
References:
1. Sumner AJ: Aberrant reinnervation. Muscle Nerve 1990; 13: 80 1-803.
2. Weiss, P., and M. V. Edds. Sensory-motor nerve crosses in the rat. J. Neurophysiol. 1945; 30: 173-193.
3. Dey JK, Boahene KDO. Facial Aberrant Reinnervation Syndrome Following Facial Nerve Injury and Recovery. Facial Plast Surg Aesthet Med. 2024 Jul 1. doi: 10.1089/fpsam.2023.0351. Epub ahead of print. PMID: 38949952.
4. Chuang DCC. Management of traumatic brachial plexus injury in adults. Hand Clinics 15(4): 737-755, 1999.
5. Chuang DCC, Ma HS, Wei FC. A new evaluation system to predict the sequelae of late obstetric brachial plexus palsy. Plast Reconstr Surg 101:673-685, 1998.
Methods: A retrospective review was conducted on patients treated for BPBI-related MARS between 1986 and 2022. A total of 62 patients with shoulder deformities and 95 patients with elbow deformities were included in the study. Two-thirds of the patients had overlapping deformities. The surgical strategy was based on the hypothesis of aberrant reinnervation syndrome, which involved multiple muscle transpositions to convert antagonists to synergists. The strategy for shoulder deformity was prioritized with shoulder abduction and external rotation restoration by transferring the shoulder adductors to the abductors. The strategy for the elbow deformity was prioritized with the elbow extension restoration by transferring elbow flexors (biceps/ brachialis) to the triceps.
Results: Postoperatively, the mean shoulder abduction improved from 70° to 148° (p<0.001), and the mean external rotation improved from 22° to 72° (p<0.001). For the elbow, the mean extension strength improved from M2 to M3-4 (p<0.0001). While initial elbow flexion strength decreased post-transfer, 78% of patients required second-stage gracilis functioning free muscle transplantation for augmentation, and the end result was successfully maintained at M3 or greater in all patients. Elbow flexion contracture also significantly improved from a mean of 40° to 10° (p=0.0293).
Conclusion: The described surgical strategies by converting antagonists to synergists by multiple muscle transfers are proven effective, durable and long-lasting for treating MARS in BPBI.
References:
1. Sumner AJ: Aberrant reinnervation. Muscle Nerve 1990; 13: 80 1-803.
2. Weiss, P., and M. V. Edds. Sensory-motor nerve crosses in the rat. J. Neurophysiol. 1945; 30: 173-193.
3. Dey JK, Boahene KDO. Facial Aberrant Reinnervation Syndrome Following Facial Nerve Injury and Recovery. Facial Plast Surg Aesthet Med. 2024 Jul 1. doi: 10.1089/fpsam.2023.0351. Epub ahead of print. PMID: 38949952.
4. Chuang DCC. Management of traumatic brachial plexus injury in adults. Hand Clinics 15(4): 737-755, 1999.
5. Chuang DCC, Ma HS, Wei FC. A new evaluation system to predict the sequelae of late obstetric brachial plexus palsy. Plast Reconstr Surg 101:673-685, 1998.
Tracks:
Reconstructive
Image
·A 9 Y/O girl presented with BPBI showing her (A) pre- and (B-C) post-op pictures. Results of 9 years postoperatively showed an impressive improvement in shoulder elevation and external rotation.