Complete Wear-Through of a Polyethylene Liner and Metal-Backed Acetabular Cup Resulting in a Unique Form of Catastrophic Total Hip Arthroplasty Failure

Case: We describe a case of total hip arthroplasty failure where a cobalt-chrome femoral head completely wore through the polyethylene liner and the titanium acetabular cup. The patient subsequently underwent revision total hip arthroplasty with acetabular revision and femoral head exchange. Conclusion: This case illustrates the natural history of catastrophic failure in a metal-on-polyethylene total hip arthroplasty design. If recognized earlier, this patient may have been a candidate for isolated liner and head exchange. Additionally, this case represents a unique complication in using mixed metals in total hip arthroplasty, where the harder cobalt-chrome femoral head wore completely through the much softer titanium component.