Catastrophic progression of the disassembly of a modular acetabular component

Disassembly of a metal-backed modular acetabular component used for total h ip arthroplasty is becoming more common. If the acetabular disassembly is d etected early, the revision procedures are relatively simple. In the case o f long-term sustained disassembly, however, there are more complicated prob lems, and more difficult revision procedures are needed. We report a case o f long-term sustained disassembly of a modular acetabular component in orde r to alert orthopaedic surgeons of the catastrophic progression to more sev ere complications, such as the loosening of the metal-acetabular component and severe acetabular osteolysis.