This is a question a lot of patients struggle with. Sometimes doctors struggle with it too. Which is the best option for any given patient? First of all, the x-ray findings are important. There are three compartments in the knee: the medial compartment (inner portion of the knee), lateral compartment (outer portion) and the patellofemoral joint (between the kneecap and the thighbone in the front). If the arthritis is isolated to one compartment of the knee (usually medial, but sometimes can be lateral or the patellofemoral joint), then the patient is a candidate for partial knee replacement. In that case, we have to decide if partial replacement is really the best option, or if total knee replacement makes more sense. If the x-ray shows arthritis in more than one knee compartment, then total knee replacement is clearly the best option. For someone with arthritis (mostly) isolated to one compartment, this article gives some data which can help with the decision making. Here are photos of a partial knee replacement and a total knee replacement.
Basically, total knee replacement has a better long term track record, a better chance of lasting for many many years. However, partial knee replacement has a lower complication rate and an easier rehab. It also feels more like your natural knee than a total knee replacement does. But, the payment for those benefits is a higher chance of needing revision surgery in your lifetime, and revision would be to a total knee replacement.
In my practice, I frequently see patients with isolated arthritis in one compartment of their knee. Usually after discussing the risks and benefits of partial knee replacement and the rehab involved, the patient decides that the discomfort they feel is not bad enough to want the surgery, and they wait. By the time the patient feels bad enough they really want surgery, usually the arthritis has progressed beyond the one compartment and the chances of excellent results with partial knee replacement go down. For this reason, I do more total knee replacement than partials. Most surgeons do.
However, for some patients unicompartmental replacement can be a great option. For example, someone who loves tennis and can’t play any more, or someone who loves to hike and can’t do it any more. Many of us would rather go through a surgery and rehab to be able to continue to do what we love in the years to come, rather than suffer the disappointment of having to adjust our lives to doing less. I totally support that.
Click here for some great information on total knee replacement.
Click here for some great information on partial knee replacement.