TOTAL HIP PROSTHESES WITH CERAMIC-ON-CERAMIC ARTICULATIONS IN THE NORWEGIAN ARTHROPLASTY REGISTER

Abstract

Introduction: In an earlier publication we analysed short-term results of total hip arthroplasty (THA) with Ceramic-on-Ceramic (C-on-C) articulations, and we found that they did not perform better than the Charnley prosthesis with a metal-on-UHMWPE articulation.

Purpose: To examine mid-term results of THA with Con-C articulations, and to compare their results with the most commonly used cemented prosthesis in our register, the Charnley.

Materials and Methods: All THAs with C-on-C articulations were uncemented and they constituted 2506 THAs.

194 of the THAs had articulations with an Alumina liner and a femoral head made of a composite of Alumina and Zirconium oxide ceramic (Biolox delta). This group had a median follow-up of only 1.1 years, and the group was therefore not included in the survival analyses.

2312 of the THAs were uncemented prostheses with Alumina-on-Alumina articulations, with a follow-up of 0–11 years (median 4.3 years). For further analyses we included only patients under the age of 80 years (n = 2209).

We compared the two most common C-on-C cup/stem combinations: Igloo/Filler (n=1402) and Trilogy/SCP (n=363), and a group of others (n= 547). Further we compared the C-on-C prostheses with cemented Charnley prostheses in patients under the age of 80 years, operated during the same time-period. We also compared the C-on-C prostheses with Charnley prostheses in a group limited to patients under the age of 60 years. Prosthesis survival was estimated by Kaplan-Meier and Cox regression analyses adjusted for age and gender.

Results: In patients under the age of 80 years the Charnley prostheses had a statistically significant higher survival than the C-on-C prostheses at 7 years (97.1% and 95.7% respectively, p=0.04). In patients under 60 years of age these analyses gave similar results, although with no statistical significant difference between Charmley and the C-on-C prostheses (p=0.06). There was no statistically significant difference in revision risk among Igloo/Filler, Trilogy/SCP, and a group of all other combinations of cup/stem with a C-on-C articulation. The most common causes for revision of the C-on-C hips were dislocation (n=18) and deep infection (n=16). 3 were revised due to a broken liner and 4 due to a broken head. Of the 194 articulations with Alumina liner and Biolox delta head, one had been revised due to fractured head.

Conclusion: With a follow up of 0–11 years, we did not find superior results of the C-on-C prostheses compared to the Charnley prosthesis. Few revisions were clearly related to failure of the articulations.