Total knee arthroplasty (TKA) boasts exceptional long-term survivorship, yet a stubborn clinical paradox remains: nearly 20% of patients report dissatisfaction following their surgery, frequently citing residual stiffness, vague pain, and an unnatural, mechanical “feel” to the joint. For decades, orthopedic engineers focused on replicating a “medial-pivot” motion, believing it defined native knee kinematics. However, modern biomechanical mapping of the anterior cruciate ligament (ACL)-intact native knee has revealed a far more complex reality.
While the native knee does pivot medially in deep flexion, its early flexion mechanics, the motion used for everyday activities like walking, jogging, or pivoting, are heavily dominated by a lateral-pivot pattern. Traditional, symmetric, non-conforming TKA bearings fail to replicate this sophisticated shift. To bridge this gap, the dual-pivot TKA was engineered. Featuring an asymmetric polyethylene insert with a highly conforming lateral compartment, the implant is designed to mechanically force an early lateral pivot before transitioning to a late medial pivot, effectively substituting for the absent ACL.
