Surgical technique
All patients were operated using the medial pivot cemented GMK Sphere system (Illustration of restoring tibial obliquity in kinematic alignment with the calipered technique presented by Intraoperatively, tibial obliquity was checked for plausibility using a tibial alignment rod in line with preoperative X-ray of the tibia (Fig. A.p. x-ray (The group with PSI was operated according to the surgical technique provided by the company (For all patients in both techniques, the desired balance was equally balanced in full extension and laterally lax in 90 degrees of flexion according to the rationale of kinematic alignment [