Abstract
Purpose of study: Sixty four patellofemoral (PF) arthroplasties in 48 patients were evaluated to assess the effectiveness of this procedure in patients with a preoperative diagnosis of patellofemoral osteoarthritis.
Methods: All patients who underwent patellofemoral arthroplasty for patellofemoral osteoarthritis between 1992 and 1998 in two district general hospitals were studied. Three authors not directly involved in the patients care assessed the patients by:
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both a modified Hungerford and Kenna knee rating system and Insall and Crosby grading system, and
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asking whether surgery had been worthwhile and whether they would go through it again.
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Serial radiographs were assessed for patellar malalignment, mechanical failure and progressive arthritic change in the knee, and
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failure was defined as a fairlpoor knee score or revision.
Results: Preoperative diagnosis included 53 patients with primary PF arthritis, 1 with post-traumatic arthritis and 1 with PF osteoarthritis secondary to recurrent subluxation. The average patient age at surgery was 73 (range 42–89) and the average length of follow-up was 41 months (range 6–90 months).
Preoperatively 17 knees had undergone arthroscopy. 36 Lubinus, 17 Cartier and 2 PFV prostheses were used. 5 patients died with 8 PF arthroplasties in situ, 1 patient lost to follow up (these patients are not included further in the analysis). 48 Patellofemoral arthroplasty knees were reviewed. 38 knees were classed as good or excellent, 10 had unsatisfactory results, and 7 were revised. 5 implants were revised to TKR and 2 were revised to PF arthroplasty (for maltracking). Subjectively 41 patients felt they were better, 5 unchanged and 2 worse.
Overall we had 69% good or excellent results, 18% poor, and 12% revised. There were no infections, no revision for loosening, and no documented difficulty in revisions. The worst results were obtained in patients with evidence of tiblo-femoral OA preoperatively and in patients with tracking problems.
Conclusion: PF arthroplasty is technically demanding. Nevertheless, providing one adheres to strict patient selection criteria, and the surgery is performed by a dedicated specialist knee surgeon, PF arthroplasty may be used to treat proven isolated patellofemoral arthritis.
The abstracts were prepared by Mr R. B. Smith. Correspondence should be addressed to him at the British Orthopaedic Association, Royal College of Surgeons, 35-43 Lincoln’s Inn Fields, London WC2A 3PN.
