Purpose. The use of uncemented unicompartmental knee prostheses has recently increased. However, few studies on the outcomes of uncemented unicompartmental knee prostheses have been performed. The purpose of this study was to compare the outcomes of cemented and uncemented Oxford unicompartmental knee arthroplasty. Materials and Methods. This retrospective observational study evaluated the clinical and radiological outcomes of 263 medial Oxford unicompartmental prostheses (141 cemented, 122 uncemented) implanted in 235 patients. The mean follow-up was 42 months in the cemented group and 30 months in the uncemented group. Results. At the last follow-up, there were no significant differences in the clinical results or survival rates between the two groups. However, the operation time in the uncemented unicompartmental knee arthroplasty group was shorter than that in the cemented unicompartmental knee arthroplasty group. In addition, the cost of uncemented arthroplasty was greater. Conclusion. Despite the successful midterm results in the uncemented unicompartmental knee arthroplasty group, a longer follow-up period is required to determine the best fixation mode. 1. Introduction Unicompartmental knee replacement arthroplasty (UKA) has been a popular treatment of osteoarthritis since the 1970s. Initial reports showed high failure rates in short-term follow-ups . Because of these high failure rates and instrumentation problems, the use of these implants decreased in the 1990s. However, during the last 20 years, UKA has become a well-established treatment method for unicompartmental osteoarthritis of the knee. Recent reports have described success rates of 90% or higher at a minimum 10-year follow-up [2, 3]. These higher success rates have been attributed to better surgical techniques, new implant designs, improved instrumentation, and careful patient selection . With the improvements in surgical techniques and instruments, this procedure has many advantages over total knee replacement such as a smaller incision, less soft tissue injury, preservation of bone stock, preservation of normal knee kinematics, less morbidity because of minimal postoperative blood loss, lower infection rate, shortened hospital stay, and rapid recovery . However, controversy on the validity and durability of UKA remains. Although UKA is associated with better clinical results than total knee replacement arthroplasty (TKA), registry data show higher revision rates . On the other hand, Goodfellow et al. reported that the revision rate is a poor and misleading outcome and
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