Effect of component size on the wear and wear debris of resurfacing hip replacements

Development of computational wear simulation of metal-on-metal hip resurfacing replacements

“…1a. The technical details of this machine have been reported elsewhere (Leslie et al, 2007). The load was applied through the head and the two-axis motions were internal/ external rotation (7101) about the vertical axis for the cup and flexion/ extension rotation (À151 to 301) about the horizontal axis for the head.…”

“…The relative sliding distances of the nodes on both the cup and head contacting surfaces were obtained using the coordinate transformation matrixes presented in Appendix A (Saikko and Calonius, 2002). The wear results of hip simulator tests for five resurfacing implants presented by Leslie et al (2007) were used to determine the wear factors. Wear factors of 1.13 Â 10 À8 (up to 1 million cycles) and 1.20 Â 10 À9 mm 3 N À1 m À1 (between 1 and 15 million cycles) were determined for the bedding-in and steady-state wear phases of the first 15 million cycles, respectively, using a trial-and-error method by matching the computed volumetric wear with the simulator results through an iterative process, the wear factor thus obtained for the steady-state wear was then used as a constant for up to 50 million cycles.…”

“…The long-term performance of MOM bearings is particularly important. Currently, only short-term to medium-term simulator testing has been carried out, up to 15 million cycles (Clarke et al, 2000;Isaac et al, 2006;Leslie et al, 2007). Clinical retrieval studies have also been generally limited to short to medium periods (Dorr et al, 2000;Lombardi et al, 2001).…”

A meta‐analysis of design‐ and manufacturing‐related parameters influencing the wear behavior of metal‐on‐metal hip joint replacements

“…Comparing eight individual studies, all authors concluded that an increased implant diameter leads to lower wear rates. [12][13][14]16,18,22,24,30 Only three studies distinguished between running-in and steadystate wear rates. 12,14,16 Smith et al 24 reported a decreasing wear rate with increasing implant diameter only for mixed lubrication.…”