要約

Thinner and larger acetabular components are more stable and are useful for resurfacing. This study performed wear simulator tests of the largest polyurethane (PUR) and highly cross-linked polyethylene (XLPE) liners available. The results were compared with conventional polyethylene (ConvPE) to determine wear, survivorship, wear debris particles generated, and oxidative degradation.
Two-piece acetabular components with a 4-mm poly liner, a 2-mm metal backing, and 1 mm of porous coating with an inner diameter of 51 mm were tested. Cobalt chromium (CoCr) and titanium nitride (TiN)-coated titanium- resurfacing femoral components were counter-face surfaces. Acetabular components were tested at 45° and 65° inclinations, with both 300 μm and an increase of 1 mm in radial clearance.
After 30 million cycles, PUR had 56% (p < 0.001) less wear and cross-linked had 93% (p < 0.001) less wear than ConvPE. TiN-coated femoral implants had 23% less wear than CoCr when used with cross-linked polyethylene. Wear increased by 16% at 65° and by 19% when radial clearance increased with cross-linked polyethylene. Polymethylmethacrylate debris ultimately failed ConvPE, but not the cross-linked polyethylene or PUR. XLPE acetabular liners are compatible with >20 years of expected use in active patients.