Prospective Randomized Study Comparing the SpheriKA® (MEDACTA) and Origin® (SYMBIOS) Prostheses During Total Knee Replacement Using the Kinematic Alignment Technique

The traditional technique for implanting a total knee prosthesis, known as mechanical alignment, does not aim to preserve the original anatomy and laxity of the knee. Instead, the implants are "systematically" aligned to create a non-naturally straight lower limb. Respectively 20% and 50% of patients with a mechanically aligned total knee prosthesis are dissatisfied with the result, and complain of residual symptoms. A newer, more physiological technique for implanting a total knee prosthesis, known as kinematic alignment, aims to recreate the unique native anatomy and laxity of each patient's knee. The kinematic alignment technique has been shown to reduce the risk of residual symptoms and thus improve the patient's experience of his or her prosthetic knee. As a result of the emergence of the kinematic alignment technique, two manufacturers have developed total knee prosthesis implants specifically for this new insertion technique. A "made-to-measure" total knee prosthesis (ORIGIN® - Symbios, Yverdon-les-Bains, Switzerland) was developed with the aim of reproducing the unique contour of each implanted knee. Another manufacturer opted to develop a generic total knee prosthesis implant (SPHERIKA® - Medacta, Castel San Pietro, Switzerland), but with a design optimized for the kinematic alignment technique. These two models of total knee prosthesis each offer advantages and limitations that need to be assessed. The main aim of this study is therefore to compare the joint perception of these 2 prostheses. It will also look at the clinical and imaging results, the biomechanics of the prosthetic knee during gait, and the muscular strength of knee extension, obtained for these 2 total knee prostheses.