Short-term clinical and radiographic outcomes of total hip arthroplasty with PMPC-grafted highly cross-linked polyethylene liners against 32-mm femoral heads

Abstract

We evaluated the clinical and radiographic outcomes of femoral head penetration and total hip arthroplasties with untreated and poly (2-methacryloyloxyethyl phosphorylcholine) (PMPC)-grafted highly cross-linked polyethylene (HXLPE) acetabular liners against 26-, 28-, and 32-mm cobalt–chromium alloy femoral heads 3\xa0years after the index surgery. Three combinations of the articulating surfaces were evaluated in the present study: untreated or PMPC-grafted HXLPE liner against 26- or 28-mm femoral heads ( n \u2009=\u200916, 24) [control (26 or 28\xa0mm) and PMPC (26 or 28\xa0mm)] and PMPC-grafted HXLPE liner against 32-mm femoral heads ( n \u2009=\u200964) [PMPC (32\xa0mm)]. The clinical outcomes improved at 3\xa0years postoperatively for the groups. No periprosthetic osteolysis or acetabular component migration was detected, and no revision surgery was performed among the groups. The steady-state wear rate of the PMPC (26 or 28\xa0mm) group (0.021\xa0mm/year) was lower than that of the control (26 or 28\xa0mm) group (− 0.015\xa0mm/year); the steady-state wear was under the clinical threshold. In contrast, the steady-state wear rate of the PMPC (32\xa0mm) group (-0.006\xa0mm/year) showed no significant difference when compared to that of the PMPC (26 or 28\xa0mm) group ( p \u2009<\u20090.01). The results obtained in the present study clearly demonstrate that PMPC-grafting onto an HXLPE surface improved the wear resistance of acetabular liners, even when coupled with larger femoral heads. Although further follow-up evaluations are required, PMPC-grafted HXLPE acetabular liners may be a promising approach to extend the longevity of artificial joints.