ARC2F ACETABULAR COMPONENT: SUDDEN ONSET OF RAPID AND MASSIVE POLYETHYLENE INSERT WEAR IN LONG TERM OBSERVATION

Abstract

Objective: we present the long-term behavior of polyethylene’s insert in acetabular implants ARC2F.

Materials and Methods: from 1989 to 1995, 668 THA’s were implanted. Mean patients age was 54 years (28–75). The preoperative diagnosis included: primary OA 501 cases, post-traumatic arthritis 24, hip dysplasia 112, AVN 31. In all cases Omnifit femoral stem with proximal HA coating and ARC2F acetabular component were used. 165 patients (182 arthroplasties) were lost to follow-up. The average time of observation was 15 years (13–18.5).

Results: all THA’s performed well without signs of wear at 10 years. No implant was revised during the first decade because of mechanical loosening. Since then, during the 13th – 14th year, a significant number of patients appeared with symptoms of polyethylene’s massive destruction and significant osteolysis at the femoral and acetabular side of the arthroplasty. We recalled all patients that could be found. Totally, 178 from 486 THA’s had similar radiographic signs of wear. Only 33 of all these had initial wrong orientation of the cup.

Conclusion: despite the excellent early and middle-term results, ARC2F shows rapid and massive wear of the insert after 12 years, probably because of degeneration and loss of polyethylene’s structural integrity due to the method of sterilization. We suggest to recall and inspect all the patients which have this kind of implant more than 12 years.