(Kiosk 1) Femoral Nerve Palsy Following Right Total Hip Arthroplasty: A Case Report

Case Diagnosis: 75-year-old female with long-standing hip osteoarthritis underwent right total hip arthroplasty complicated by femoral nerve injury.

Case Description or Program Description: A 75-year-old female with long-standing hip osteoarthritis underwent right total hip arthroplasty (THA). Following the procedure, she reported new right lower extremity weakness and numbness. Examination revealed markedly decreased strength in right hip and knee flexion, anteromedial thigh and leg numbness, and absent right patellar reflex. Femoral nerve palsy was suspected. Possible etiologies included compression, stretch, inflammation, or laceration injury to the femoral nerve in the perioperative period. Imaging was pursued to assess for reversible causes potentially amenable to surgical intervention. Magnetic resonance imaging demonstrated prominence of right femoral nerve at proximal segment with surrounding soft tissue edema. No surgical intervention was warranted.

Setting: Academic, acute inpatient rehabilitation facility

Assessment/Results: Patient was transferred to an inpatient rehabilitation facility, where her functional mobility and strength considerably improved at time of discharge home. She required a knee immobilizer to minimize knee buckling and reduce her fall risk. She progressed to independence with bed mobility, transfers with rolling walker, and ambulation and stair negotiation with bilateral handrails using a knee immobilizer and rolling walker, despite minimal quadriceps activation and deconditioning. However, she developed a small heel pressure injury resulting from right lower extremity immobility, which was healing at time of discharge. Nerve conduction studies and electromyography was recommended as an outpatient if weakness and sensory deficits persisted.

Discussion (relevance): Motor nerve palsy as a complication of total hip arthroplasty is a rare complication with significant morbidity and quality of life impact. Specifically, prevalence of femoral nerve palsy after direct anterior approach THA may range from approximately 0.1-0.4% and is often related to misplacement of the anterior acetabular retractor. Important considerations for patients with post-operative femoral neuropathies include skin protection and knee buckling prevention.

Conclusions: While patients often achieve full or near-full motor recovery, the timeline can range from weeks to several years, resulting in long-term impact on patient function, mobility, and overall health.