At the recent Knee Society meeting in Orlando, Florida, March 5, 2016, there were several talks regarding the ideal limb alignment after a knee replacement and how to get it. There has been debate over the years about classic “mechanical alignment” versus “anatomic alignment” versus kinematic alignment. All three philosophies have been utilized and reported on extensively. These various alignment techniques can utilize traditional or mechanical instruments which involve alignment rods that go up the inside of the thigh bone and on the outside of the shin bone or can be accomplished using computer-assisted techniques or robotically-assisted techniques. All of these various instrument systems, including patient-specific guides which are made uniquely for each patient from a pre-op CT scan or MRI, can have a positive effect on cutting down outliers from the idealized alignment of the limb. It seems that a variety of these newer techniques, which can be computer-assisted and robotically-assisted, can greatly benefit the less experienced surgeon and can be a valuable learning total for more experienced orthopedic surgeons.
The take away message from these various talks is that it is important to get the leg well-aligned when doing a knee replacement surgery and in association with the alignment, balancing the soft tissue to make sure that the ligaments surrounding the knee are stable throughout the arc of motion. Over the years, the importance of obtaining a well-aligned leg with proper soft tissue balance has been refined.