As the general understanding or normal knee kinematics became more widely understood, a clear shift in prosthetic design logic began to emerge. The under­standing that the medial compartment, composed of a larger medial femoral con­dyle with a congruent medial tibial plateau and xed medial meniscus, experiences less rollback compared to the lateral compartment drove the development of medial­congruent (MC) tibial inserts. The idea was to replicate the native knee anatomy to allow for a more stable medial compartment contact point [51]. This pivoting around the medial joint is relatively xed while the lateral joint rotates around the medial center of rotation [52]. Several companies incorporated this concept in their designs dubbing them “medial congruent,” “medial dished,” or “medial stabilizing” depend­ing on the company. A major difference between the two groups of MC prostheses is whether the medial condyle has a single radius of curvature or multi-radius of curvature in the sagittal plane. In the single radius TKA, the constant radius of cur­vature leads to isometric tension on the supercial medial collateral ligament throughout knee range of motion [53]. The multi-radius TKA designs, also referred to as a “J-curve,” have a larger radius of curvature anterior and a smaller radius of curvature more posterior allowing increased exion and femoral rollback [54, 55].