Abstract
The aim of this study was to report our experience of patellofemoral arthroplasty in isolated osteoarthrosis.
Material and Methods: The Lubinus Patellofemoral Arthroplasty was performed between 1989 and 1995 in 76 knees. The Avon Patella Femoral Arthroplasty was used from 1996 to 2001 in 187 knees. The average age of the patients was 65.5 years (range 36–87) with a male to female ratio of 1: 5. All the patients have been prospectively reviewed with standard radiographs, the Bristol Knee Score, and more recently Bartlett and Oxford scores.
Results: Patients with the Lubinus prosthesis were followed for an average of 7.4 years (range 5–10 years). Eleven patients (14 knees) have died and the remaining 62 knees have a 100% follow-up. The cumulative revision rate was 28% (21 out of 76). Survivorship at 8 years was 65% (Cl 49 to 77) for revision and 48% (Cl 36 to 59) for revision plus moderate pain. The two main complications were Maltracking 32% and progressive tibio-femoral arthritis in 9%.
The Avon Arthroplasty with improved design features for better tracking and congruity was introduced in 1996 and 187 have now been inserted in 147 patients. One hundred and nine knees have been followed for 8 months and 82 have completed the 2 year follow-up. Two patients have undergone revision to a TKR 97.5% (survivorship 2 out of 82). Three patients have had a unicompartmental arthroplasty added for disease progression. There have been no cases of patella maltracking or subliaxation.
Four year survivorship for moderate pain and revision is 96% (79 out of 82). Functional scores compared favourably with parallel series of total knee replacements.
Conclusion: The medium-term results of the Lubinus Patello Femoral Arthroplasty are unsatisfactory. We suggest the use of this prosthesis should be discontinued. The Avon Arthroplasty has improved results in the short-term.
The abstracts were prepared by Mr Roger Smith. Correspondence should be addressed to him c/o British Orthopaedic Association, Royal College of Surgeons, 35-42 Lindoln’s Inn Fields, London WC2A 3PN.
