In 1971, for purpose of reduction of peak stress occuring in cement and trabecular bone of the acetabulum, Harris reported a series of metal-backed acetabular components with removable polyethylene liners that could be replaced if excessive wear occured. Modular designs of hip prostheses have become popular recently, but they introduce the risk of disassembly of the components postoperatively. And introduce of loosening and infection of femoral or acetabular components by debris of polyethylene liner. We report a case of mechanical disassembly of polyethylene liner in cementless metal backed cup, and review previously reported articles.