Compressive Iliac Aneurysm: A Rare Case of Sciatic Nerve Palsy after Total Hip Replacement

Introduction: Sciatic nerve injury is an aknowledged iatrogenic complication of total hip arthroplasty (THA), usually associated with posterior surgical approaches. Its temporal proximity with arthroplasty produce a positive causal relation between the two entities, but it is worth recalling that there may be other causes unrelated to arthroplastic procedure for neurological injury. Case presentation: We present a case of a male patient, currently with 83yearsold, with left hip total replacement history. In 2004the patient underwent right femoral-popliteal bypass because of a popliteal thrombosed aneurysm. Right hip arthroplasty was repeatedly delayed until 2012, when he was successfully operated. Six weeks after surgery, the patient had an episode of strong leg pain followed by paresthesia and reduction of ankle dorsiflexion strength. Electromyography was performed and showed highsciatic nerve injury. CT scan showed a mass exerting compressive effect on the sciatic notch. Later was performed angio-CT scan which revealed aneurysm of the right internal iliac artery, being treated by endovascular approach. In later angiographic control was confirmed regression of the aneurysm. Currently the patient has no pain, but has not regained dorsiflexion capacity of the foot. Discussion: This case alerts us to the need for complete clinical evaluation of the patient and the attention to differential diagnosis, before a situation of the sciatic nerve palsy.