Congenital subaxial cervical subluxation presenting as a bilateral Erb's palsy: surgical management, rehabilitation, and outcome.

INTRODUCTION: Subaxial spine injuries during infancy are uncommon.

CASE REPORT: We present the case of an infant referred to our brachial plexus clinic with proximal weakness of both arms noted immediately following a complicated breech delivery. Nerve conduction studies were consistent with bilateral proximal upper plexus injury; however, radiological evaluation revealed a C4-C5 subluxation and MRI features of bilateral C5 root avulsions. He was immobilized in a cervical-body orthosis and underwent open reduction and posterior C4-C5-C6 fixation at 10 weeks age using luque rods, sublaminar wires, and rib graft. The spine was immobilized in a custom molded cervicothoracic brace for a total of 3 months, and a home exercise program prescribed. Follow-up radiographic evaluation showed good posterior bony fusion by 2 months but persistent bilateral proximal upper limb weakness with reduced compound motor action potential (CMAP) amplitudes of the axillary and musculocutaneous nerves. Bilateral supraclavicular exploration and C5 root neurotization using the ipsilateral C7 nerve roots were performed at 7 months of age. Voluntary biceps activity followed by voluntary external rotation with gravity eliminated was noted within the next 2-3 months. He progressed to develop near normal motor control of bilateral upper limbs within 1 year.

CONCLUSIONS: We wish to report this rare entity and our favorable outcome using a strategy of early spinal stabilization and neurotization repair to restore function following proximal nerve root injury.