Delayed Presentation of Sciatic Nerve Injury after Total Hip Arthroplasty: Neurosurgical Considerations, Diagnosis, and Management

Abstract

Introduction Approximately 225,000 primary total hip arthroplasties (THAs) are performed in the United States per year, and projections indicate that more than 4 million THAs will be performed annually by 2030. 1 Neurologic injury after THA is reported to occur in 0.09 to 3.7% of primary THAs and 0 to 7.4% of revision THAs. 2 Noted causes of neurologic injury include direct intraoperative nerve injury, leg lengthening, excess retraction, cement extravasation, cement-related thermal damage, patient positioning, and postoperative hematoma. 2 The majority of these injuries are symptomatic within the early postoperative period and can be managed conservatively with close follow-up. Delayed onset of neuro-logic injury is a rare complication with a unique differential diagnosis requiring appropriate management. We report a case of neuropathy caused by malposition of an acetabular cup screw causing direct injury to the sciatic nerve. The patient developed progressively worsening loss of ankle dorsiflexion, resulting in complete footdrop 2 years after initial THA. The presentation, intervention, and outcome of other cases of delayed neuropathy are reviewed in the present report. Delayed neuropathies are most often caused by irritation from hardware, component failure, or wear-related pseudotumors. Keywords ► total hip arthroplasty ► delayed neuropathy ► sciatic nerve ► operative outcome Abstract Background Total hip arthroplasty (THA) is an established treatment for end-stage arthritis, congenital deformity, and trauma with good long-term clinical and functional outcomes. Delayed sciatic nerve injury is a rare complication after THA that requires prompt diagnosis and management. Methods We present a case of sciatic nerve motor and sensory deficit in a 52-year-old patient 2 years after index left THA. Electromyography (EMG) results and imaging with radiographs and CT of the affected hip demonstrated an aberrant acetabular cup screw in the posterior-inferior quadrant adjacent to the sciatic nerve. Case Description The patient underwent surgical exploration that revealed injury to the peroneal division of the sciatic nerve due to direct injury from screw impingement. A literature review identified 11 patients with late-onset neuropathy after THA. Ten patients underwent surgical exploration and pain often resolved after surgery with 56% of patients recovering sensory function and 25% experiencing full recovery of motor function. Conclusions Delayed neuropathy of the sciatic nerve is a rare complication after THA that is most often due to hardware irritation, component failure, or wear-related pseudotumor formation. Operative intervention is often pursued to explore and directly visualize the nerve with limited results in the literature showing modest relief of pain and sensory symptoms and poor restoration of motor function.