Poly-Wear The assessment of polyethylene wear in joint replacement is important because wear debris is believed to cause osteolysis which leads to aseptic loosening. [1, 2]

The measurement of wear in total hip arthroplasty has been studied in a number of cases and is possible because of the highly conforming geometry of the joint which allows accurate measurements with patients standing [3-16].

Studies of wear in hips has shown decreased wear of highly cross-linked polyethylene (HXLPE) compared to standard ultra–high-molecular-weight polyethylene (UHMWPE) liners [16] and have examined the effect of sterilization methods [9].

In the study of wear in total knee arthroplasty, the techniques are more challenging because of the lack of conformity between the polyethylene insert and the femoral component. Combining RSA and 3D models of the implants has been used in initial investigations into knee wear [17, 18].