Early Experience with a Modern Generation Knee System: Average 2 Years’ Follow-up

Abstract

Arthritis in the knee is a leading cause of pain and disability with total knee arthroplasty (TKA) often the treatment of choice after failure of more conservative treatments. TKA has been demonstrated to be one of the most successful procedures performed. However, despite the good long-term survivorship rates, patient satisfaction is still an issue post TKA with over 20% of patients exhibiting patient dissatisfaction most commonly due to anterior knee pain (over 18-28% patients) and mediolateral or varus-valgus instability. Recent studies have demonstrated that collateral ligament strains are altered post TKA which may lead to laxity and/or tightness of the ligaments resulting in patient discomfort, pain, stiffness and/or instability post TKA. As a result, it may be beneficial to ensure ligamentous strains after TKA are similar or close to the native situation. The purpose of this study was to evaluate the clinical and radiographic results of the Unity Knee™ Total Knee System (Corin Ltd, Cirencester, UK), a modern generation, single-radius total knee replacement (TKR) and its accompanying instrumentation which is designed to help maintain proper ligament balance and restore the medial jointline. A total of 89 knees (89 patients) were implanted with the device in a single surgeon series. All patients were assessed using the American Knee Society Score (AKSS), the Oxford Knee Score (OKS), and radiographs. There was 1 revision due to infection and Kaplan-Meier survivorship was 98.9% at 2 years. The mean AKSS knee score for the total cohort was 87.1 ± 7.98 and the mean Oxford Knee score was 45.89 + 3.69. Radiographic review found no signs of radiographic failure in any of the knees. This study demonstrates good survivorship, clinical, and radiographic results at 2 years for this TKR.