432 A Rare Case of Ipsilateral Foot Drop Due to Common Peroneal Nerve Palsy at the Level of Fibular Head Following Total Hip Arthroplasty

Abstract

Abstract Background Common peroneal nerve (CPN) palsy after primary total hip arthroplasty (THA) is a rare complication with poor functional outcome and has a prevalence of 0.3-2.1%. Case Presentation A 77-year-old gentleman was diagnosed with severe osteoarthritis of the left hip and underwent a hybrid left total hip replacement via posterior approach in right-lateral position. There was no usage of spinal anaesthesia, leakage from the wound, intra-operative nerve injury or any localised haematoma. Post-operatively on day 3, he was noted to have foot drop with loss of foot eversion and dorsiflexion with sensory loss along the distribution of the superficial peroneal and tibial nerve. Clinical Outcomes Nerve conduction study of left lower limb showed absent left superficial peroneal sensory response, absent left peroneal to extensor digitorum brevis and tibialis anterior motor responses with denervation across the anterior and lateral left lower leg muscles suggestive of a severe partial lesion of the left common peroneal nerve at the level of fibular head. Patient was placed in a foot drop splint with follow-up neurological evaluation. Discussion Post-operative CPN palsy are mostly neuropraxias caused due to direct compression, either by surgical instruments or anatomical structures, or from tension or ischemia to the nerve during intra-operative limb manipulation or limb lengthening. Additionally, usage of cement less components combined with Enoxaparin or due to any haematoma may compress the nerve. Age, BMI and initial severity of sensory and motor neurological deficits are prognostic factors indicating recovery. Full recovery is between 16-56% of cases at an average of 15 months.