A Comparison of Vitamin E Diffused Highly Crosslinked Polyethylene Wear Between Cobalt-Chrome Ball Heads and Zirconia Toughened Alumina Ball Heads After Total Hip Arthroplasty: A Multicenter Study

抄録

Introduction: To reduce the risk of oxidation without sacrificing the strength or wear properties of the polymer, vitamin E-diffused highly cross-linked polyethylene (HXLPE) was introduced. For the countersurface of the articulation couple, zirconia toughened alumina (ZTA) was invented to overcome the brittleness of alumina ceramic. The aim of this study was to compare the wear properties and the clinical outcomes of ZTA ceramic femoral head (Delta) on vitamin E diffused HXLPE liner with those of cobalt-chrome (CoCr) head for the Japanese female patients with a diagnosis of unilateral dysplastic coxarthritis.

Patients and methods: A total of 144 patients consented to participate in this blinded randomized controlled study in four Japanese hospitals. Finally, 65 patients in the CoCr group and 63 patients in the Delta group were included in the analysis. The center of the femoral head in the acetabular shell was measured within six weeks after the operation, at 1, 2 and 3 years using the Martell Hip Analysis Suite. Clinical outcomes were evaluated using Harris Hip Score (HHS), Western Ontario and McMaster University Osteoarthritis Index (WOMAC), UCLA Activity Score.

Results: The total femoral head penetration at three years was −0.02mm (IQR: −0.32, 0.29) in CoCr group, and 0.12mm (IQR: −0.32, 0.64) in Delta group. There was no difference between the two groups in terms of HHS, WOMAC, UCLA Activity Score.

Conclusions: The short-term wear of vitamin E diffused HXLPE with ZTA ceramic ball was similar to that with CoCr ball. Following the results of clinical outcomes, an advantage of ZTA ceramic ball on vitamin E diffused HXLPE was not recognized at three years postoperatively.