Late disassembly of modular acetabular components. A report of two cases.

We report two cases of late disassembly of modular acetabular components, 4 and 5 years after implantation. One was revised immediately after the disassembly and one after 4 months, the latter demonstrating excessive wear of metal and polyethylene. Radiographs showing eccentric displacement of the femoral head in the cup associated with a dark, curved shadow representing the displaced polyethylene insert identify this type of implant failure.