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. (c) 2025 The Authors. Published by Elsevier Inc. on behalf of The American Association of Hip and Knee Surgeons. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/ 4.0/).