Medial UKA (unicompartment knee arthroplasty, also known as a partial knee replacement) is surgery in which only the diseased part of the knee is repaired with artificial material.

Similarly to the full knee replacement, UKA is performed using a battery-powered saw, a small chisel, etc. However, the UKA is a much less invasive alternative to the full knee replacement. Not only is it less invasive than TKA, but it allows a more natural movement and feel after it heals.

Other advantages include:

1. Faster recovery
2. Less blood loss and less pain
3. Lower complication rate

In so many words, if the arthritic disease of the knee is limited to the medial compartment, UKA is a better operation than TKA.

Unicompartment knee arthroplasty

Compared to TKA (full replacement)

1. The lateral compartment of the knee is left alone
2. The patellofemoral compartment of the knee is also left alone
3. The cruciate ligaments are left alone
4. Only the diseased medial bone and meniscus is removed and replaced with artificial materials

Patients are often worried about the need to have more surgery such as "full replacement" later in life. While it is true that the odds of redo surgery are slightly higher, statistical studies show that 20 years post-surgery 91% of Oxford® Knee patients still had their original partial knee replacement implants.

How does one know whether a UKA is the right operation for a particular patient?

I apply the Nuffield criteria in order to determine whether UKA is the correct operation for a patient, including obtaining stress xrays of the knee.

Generally speaking, the presence of pain at rest and pain that involves the entire knee makes it less likely that the UKA is the right operation for that particular circumstance.

Patients who would benefit from medial UKA have pain that is limited to the medial (inside) of the knee, and pain that occurs with weight bearing.

What prosthesis do I use for UKA?

I have years of experience with the Oxford® prosthesis and I use it exclusively for this purpose.