Dual-mobility (DM) articulations may be useful for patients at increased risk for instability in primary and revision THA. While DM articulations are becoming increasingly popular, its routine use in primary THA is more uncertain. Even less is known about femoral head penetration in DM designs manufactured with highly cross-linked polyethylene infused with Vitamin E (E-HXLPE). The purpose of this study was to evaluate the early clinical results and femoral head penetration rates of primary THA implanted with DM E-HXLPE. Between 2012 and 2017, 105 primary DM THAs were performed using a one-piece acetabular shell, 28mm ceramic head, coupled with an E-HXLPE outer bearing via a standard posterior approach. Three patients refused follow-up after six months. 102 hips (92 patients) were available for review. The diagnosis was 99% OA. Average age was 65.7 years (33–90 years). 56% of patients were female. The most common femoral head size was 50mm (range, 44–60mm). The average thickness of the E-HXLPE outer bearing was 22.7mm (range, 16–32mm). Patients were followed at two months (baseline radiograph), six months, one, three, five, and seven years. Harris hip scores (HHS), UCLA activity score, and femoral head penetration (Martell method) were obtained at each visit beyond two months. Follow-up averaged 3 years (range, 1–7 years).Introduction
Methods
We have made a retrospective review of 185 cemented Charnley total hip arthroplasties performed between 1970 and 1974 to determine the relationships between radiological variables and failure of the femoral and acetabular components. We measured the acetabular wear, the orientation of the cup, the thickness and consistency of acetabular and femoral cement mantles, radiolucency and femoral alignment. The mean follow-up was for 11.7 years. Femoral loosening was demonstrable radiologically in 15 hips (8.1%), ten (5.4%) of which were revised during the period of follow-up. Only when the first postoperative radiograph showed a thin cement mantle in Gruen zone 5 was there a significant association with failure of the femoral component. There were 12 loose acetabular components (6.5%), nine (4.8%) of which were revised. When the initial radiograph after operation showed radiolucency in DeLee and Charnley zone 1, the incidence of acetabular loosening was 28.21%. If such radiolucency was not present, the incidence of acetabular loosening was only 0.69%. Our findings emphasise the importance of careful cementing.
