Acute Stress Fracture of the Pelvis after Total Hip Arthroplasty: A Case Report

INTRODUCTION: Acute hip pain following total hip arthroplasty (THA) could have numerous causes to include stress fracture of the pelvis. Stress fractures of the pelvis are rare and have been reported to involve the medial wall and the pubic ramus. A unique case is presented demonstrating the clinical presentation and management of an acute stress fracture of ilium and anterior column following a THA. CASE REPORT: A 72-year-old man underwent an uncomplicated right THA. He was noted to have femoral head resorption and thin osteoporotic bone intraoperatively. He initially did well postoperatively and ambulating without pain or assistive devices. Within 1 month of surgery, he returned with acute right hip pain without any traumatic event. Radiographs showed migration of the acetabular component and computed tomography scan confirmed a fracture through the ilium. The patient underwent revision surgery, where the fracture was reduced and internal fixation was achieved with a reconstruction plate and acetabular cage construct. At 9 months postoperatively, the patient remained pain-free with full weight bearing and with stable radiographs. CONCLUSION: Elderly patients who undergo THA may have low bone mineral density. These patients can develop stress fractures in their pelvis after surgery. These fractures may involve the medial wall, posterior column, or posterior wall. In patients who develop atraumatic pain postoperatively, it is important to consider for potential stress fractures of the ilium and evaluate appropriately with imaging. In these cases, revision surgery can be necessary to provide fixation of the stress fracture.