Deep Peroneal Nerve Neurotmesis Following Traumatic Lower Extremity Injury

Case at a Glance

A 34-year-old male presents with persistent foot drop and numbness following traumatic right lower extremity injury, with EMG findings consistent with deep peroneal nerve neurotmesis.

Patient's Story

The patient sustained a traumatic injury to his right leg in a motor vehicle accident. Following the initial trauma, he developed progressive weakness in dorsiflexion of the foot and numbness over the dorsal aspect of the foot. Despite several months of conservative management and physical therapy, symptoms persisted without significant improvement, prompting further neurological evaluation.

Initial Assessment

Physical examination revealed complete foot drop with inability to dorsiflex the foot against gravity, numbness in the first web space distribution, and weakness of toe extension. The patient required an ankle-foot orthosis (AFO) for ambulation. Lower extremity edema was noted. No other neurological deficits were present.

The Diagnostic Journey

Electromyography and nerve conduction studies were performed approximately 4 months post-injury. Results demonstrated absence of voluntary motor unit potentials in the tibialis anterior and extensor digitorum longus muscles, ongoing denervation changes with fibrillation potentials and positive sharp waves, and complete or near-complete interruption of deep peroneal nerve conduction with no evidence of functional reinnervation.

Final Diagnosis

Deep peroneal nerve neurotmesis secondary to traumatic lower extremity injury

Treatment Plan

Initial conservative management included physical therapy focusing on range of motion exercises, electrical stimulation, and gait training with AFO. Multiple specialist consultations were obtained: one neurologist recommended observation for 18-24 months to allow for potential spontaneous nerve regeneration, while a peripheral nerve surgeon discussed surgical options including nerve transfer or tendon transfer procedures if no improvement occurred. The patient was started on vitamin B12 supplementation and alpha-lipoic acid as adjunctive therapy.

Outcome and Follow-up

Patient continues conservative management with regular neurological monitoring. Surgical intervention with nerve transfer or tendon transfer procedures remains under consideration if no functional improvement is observed by 18-24 months post-injury. Patient maintains functional ambulation with AFO assistance and continues physical therapy to prevent contractures and maintain muscle conditioning.