Abstract
Introduction and Aims: Use of bioceramic coatings to enhance fixation of joint arthroplasties is a relatively new concept that has yet to prove long-term, reliable results in knee arthroplasty. The purpose of this study was to prospectively report on the medium- to long-term outcomes of an uncemented, hydroxyapatite coated total knee replacement (TKR).
Method: Between August 1992 and 2002 all patients in a consecutive series requiring primary TKR were treated with an uncemented, hydroxyapatite coated, posterior cruciate ligament retaining prosthesis implanted by the senior author. A combined Knee Society Clinical rating score (producing a maximum score of 200) was prospectively collected prior to surgery and post-operatively at three and six months and one, two, five and 10 years thereafter. Fluoroscopically controlled interface images were obtained from the first 161 knees immediately and again at two years post-operatively to evaluate the progression of osseointergration.
Results: One thousand two hundred and thirty-five patients (M:F; 605:630) with a mean age of 67 years (range 34–97 years) underwent TKR mainly for osteoarthritis (94%) and inflammatory arthropathies (3%). Mean follow-up was 78 months (range 20–145 months). There were 720 unilateral and 1030 bilateral replacements (824 simultaneous, 206 staged) with 1750 replacements in total. Mean pre-operative knee score was 97 with a range of movement (ROM) from seven to 114 degrees. At five and 10 years, scores were 182 and 178 with a ROM of one to 114 and zero to 112 degrees respectively. Sixty-one (4.9%) patients have died since surgery including two peri-operative deaths for MI. There have been 12 (0.7%) cases requiring revision, primarily for septic loosening (six cases). There have been 16 deep infections (0.9%), 29 proven pulmonary emboli (1.7%) and five periprosthetic fractures (0.3%). There has been one (0.06%) case of aseptic loosening requiring revision.
Conclusion: These results reveal with an adequately designed prosthesis the use of hydroxyapatite in TKR produces reliable osseointergration that is comparable to other methods of fixation as demonstrated with minimal revision rate and incidence of loosening. The clinical results produce excellent ROM with good medical and functional outcomes in the long term.
These abstracts were prepared by Editorial Secretary, George Sikorski. Correspondence should be addressed to Australian Orthopaedic Association, Ground Floor, The William Bland Centre, 229 Macquarie Street, Sydney, NSW 2000, Australia.
At least one of the authors is receiving or has received material benefits or support from a commercial source.
