A fifteen year review of hydroxyapatite ceramic coated hip implants : A clinical and histological evaluation
Category: Furlong Clinical Results
J.M. Buchanan, A.J. Malcolm
Sunderland Royal Hospital, England; University of Newcastle upon Tyne, England
Aims: To ascertain whether or not Hydroxyapatite Ceramic coated implants (HAC) will survive more than ten years after implantation.
Method: Since May 1988 HAC hip prostheses have been used in more than 1900 operations. The patients are assessed using the Harris Hip Score (HHS) pre- and postoperatively and then annually. Post mortem specimens are sectioned to study bone integration to the HAC. Initial X-rays are reviewed and followed by annual X-ray after five years.
Results: HHS indicates that the system works with only 7% scoring less than 90. Only seven hips had a deterioration in HHS associated with the implant including three with aseptic loosening. One had catastrophic third body wear in a plastic acetabular liner. Histology shows early bony bonding (six weeks) to HAC particularly in cancellous bone. The HAC coating behaves biologically and is ultimately replaced with bone with no intervening fibrous layer: a Perfect Fit (seen at variable times after six years)
Conclusions: HAC hip prostheses provide a ten year, pain free arthroplasty. There is one case of polyethylene debris / granuloma disease. Maximum follow-up is fifteen years. Longer term results will be awaited with interest.
Paper presented at EFORT 2003, Helsinki, Finland, June 4 – 10 2003.