Mechanical Alignment vs Kalipered Kinematic Alignment Total Knee Arthroplasty

Knee replacement surgery can be performed in one of two ways. Traditionally the goal was for the new joint to be in a neutral position with respect to the femur (thigh bone). This is called Mechanical Alignment (MA). The neutral position is different than the human knee's natural position, so MA often requires the surgeon to make additional cuts to the ligaments and other soft tissue around the knee. More recently surgeons have started to place the new joint in a position that more closely replicates the natural alignment of the human knee. This is called Kinemetic Alignment (KA). KA can be done without additional soft tissue dissection but the procedure requires a higher level of precision that can be difficult to achieve in every case. Some studies have found no difference in outcomes between MA and KA, whereas others have found KA to be superior. But these were small studies or studies that did not consider patient-rated outcomes.