Medial Unicondylar Knee Arthroplasty vs Total Knee Arthroplasty

In treatment of isolated medial unicondylar osteoarthritis of the knee (MU-OA), it is possible to choose between surgery with a unicondylar knee arthroplasty (UKA), or a total knee arthroplasty (TKA). Supporters of TKA suggest that this treatment gives a more predictable and better result, whereas supporters of UKA suggest that it is unnecessary to remove decent and functional cartilage in other compartments, and also that generally the UKA gives better results under certain circumstances. If the UKA is worn out or loosens, revision surgery will be relatively easy, whereas revision-surgery after a TKA can be much more problematic. Also, it is of great interest to measure the direct costs of these treatments. Both general hospital costs, but also costs in societal in terms of sick-days, pain-killer expenditure, and physiotherapy. The aim of this study is to compare the results, in terms of 1) patient-reported outcomes, 2) clinical results including prosthetic survival and 3) costs.

Inclusion Criteria: Anteromedial OA of the knee as diagnosed on posteroanterior and lateral projections of the knee, and symptoms of sufficient severity to justify arthroplasty. Each patient can only participate with one knee, but may be eligible with both knees. Eligibility is independent of possible previous procedures to index or contralateral knee, and to age, sex, occupation and etiology of the anteromedial OA. Bone og Bone medially on pre-operative radiographs. Exclusion Criteria: 1. knee instability caused by either cruciate or collateral ligament insufficiency, 2. rheumatoid or other inflammatory arthropathy, 3) lateral patellar subluxation on skyline views with articular cartilage thinning of the patellofemoral joint. Specific exclusion criteria for study participation are: 1) age below 18 years of age, 2) limited possibilities of understanding and assessing study information (e.g. severe psychiatric or mental conditions and non-Danish speaking), 3) occupational or personal relation to surgeons responsible for treatment (e.g. employment in participating orthopedic departments).