Abstract
We report a 10% failure rate for aseptic loosening and overall revision rate of 15% at 5 years mean follow up in 190 patients using the Cormet 2000 Dual coat ace-tabular component.
Between April 2001 and March 2004, this cup was used in our region by 4 surgeons. It was peripherally expanded and comprised a cobalt chrome shell, plasma sprayed with a further layer of cobalt chrome which was then coated with hydroxyapatite. This backing has since been abandoned in favour of a titanium plasma coat beneath the hydroxyapatite because of a higher than expected incidence of early loosening.
There were 190 cups implanted in 174 patients, 142 with resurfacing heads. The average age was 54 and 99 were male.
Revision for aseptic loosening was required in 20 cups (10%) at a mean interval of 23 months including five within 2 months, Of the early revisions three developed a deep infection. Undiagnosed groin pain in four further patients appeared at revision to arise from an inflamed bursa secondary to impingement of psoas tendon on the rim of the cup. There was one primary infection, one infection following revision of a trochanteric osteotomy and two neck fractures. Persistent unexplained groin pain was seen in three patients who have declined further surgery
Failure of this backing to integrate with bone led to an unacceptably high early loosening rate. Positioning of the larger resurfacing cups is critical to avoid painful irritation of psoas. Early revision carries a high risk of infection.
The abstracts were prepared by Mr D J Bracey, Editorial Secretary. Correspondence should be addressed to him at Royal Cornwall Hospital, Treliske, Cornwall TR1 3LJ, England.
