The Femoral Neck-Bite Sign: A Radiographic Indicator of Catastrophic Sandwich Liner Failure in Total Hip Arthroplasty.

In this case report, we present the failure of a sandwich liner resulting in extensive notching of the femoral neck as well as metallosis and osteolysis in a 74-year-old woman. All implants were removed due to large bone defects and a cage was combined with a polyethylene cup, ceramic head, and modular cementless stem. Clinical and radiological follow-ups were conducted at 6 weeks and 6 months postoperatively, showing postoperative patient-reported outcome measures that were marginally inferior to the preoperative status. We discussed that a timely revision surgery was nonetheless warranted in order to prevent further bone loss and systemic toxic metallosis. We introduce the Femoral Neck-Bite Sign, a radiographic finding that may indicate ceramic liner fracture as in this case or implant impingement resulting in femoral notching.