Abstract
Aims: The rate of polyethylene wear has been reported to be considerably higher with uncemented metal backed cups articulating with cemented as well as uncemented femoral components. There are many reports comparing wear between cemented all polyethylene and uncemented metal backed cups from different manufacturers, however there are no reports comparing wear of polyethylene manufactured in identical method.
Patients and methods: 361 consecutive hips between 1988 and 1995 were operated at our hospital by using either cemented all polyethylene Zimmer Flanged (ZF) or uncemented Harris-Galante (HG) acetabular component rticulated with Exeter polished tapered cemented stainless steel stem with a 26mm size head. A total of 107 hips (75 ZF and 32 HG) were excluded. A custom-made computer programme was used to assess polyethylene wear (by using the method of Livermore etal). A statistical analysis was used to find average annual wear and significance of difference in the wear of ZF cups and HG cups using student’s t-test.
Results: There were 87 male and 167 were female patients with an average age of 63.92 years (18 – 86). The average follow-up for ZF cups was 3.85 years (2.5 – 5.4). and for HG cups was 5.3 years (2.5 – 9.3). The mean annual wear rate of ZF cups was 0.127mm (SD 0.088). For HG cups the mean was 0.1388mm (SD 0.086).
Conclusion: Polyethylene ZF cups have wear characteristics similar to HG cups at a mean follow-up of 4.6 years.
Theses abstracts were prepared by Professor Dr. Frantz Langlais. Correspondence should be addressed to him at EFORT Central Office, Freihofstrasse 22, CH-8700 Küsnacht, Switzerland.
