Frequently, this is the compartment that develops symptomatic osteoarthritis first and can lead to the leg appearing “bowlegged”. We call this genu varus. Less frequently, the outermost part of the knee joint or lateral compartment initiates the arthritic process. This can be painful and some people may complain that their leg is becoming “knock kneed”. This condition is referred to as genu valgus. Finally, the articulation between the kneecap and femur can become arthritic and painful. Often this patellofemoral joint will wear out secondary to the arthritic process which first starts in one of the other two compartments. Imagine how the tracking of the patella becomes compromised as the alignment of the leg/knee is altered. Eventually, all three compartments become involved in the arthritic process.

A partial knee replacement (PKR) attempts to interrupt this progression by only treating the involved compartment(s). Most patients report a much faster and easier recovery than after a TKR because significantly less dissection is done and the uninvolved compartments and structures of the knee are not violated. Many patients also report that the partial knee replacement feels “more natural” than TKR. This may be because there is less interruption to normal neurologic pathways and because the cruciate ligaments and the uninvolved compartments are not violated.

The historic track record of PKR has been less consistent than with the TKR. Optimizing component balance and tracking is critical. Robotic technology is proving to be a powerful technology making performing PKR more precise and predictable.  In my experience, PKR is an elegant and wonderfully effective way to treat certain conditions.

Critical is that the indications to perform the surgery are appropriate and the technique is optimized. It has the potential of stopping the arthritic progression to end stage disease. In my experience, using the MAKO robotic-assisted technique has vastly improved the accuracy and reproducibility of my performing these procedures. Visit the Video Gallery to see a Video of the MAKO robotic-assisted technique.