Total knee replacement (TKR) has become a very popular way to treat pain and loss of function from osteoarthritis of the knee. Although the knee joint itself may need replacing, sometimes the kneecap (patella) is just fine. It moves up and down over the joint just fine.
Some researchers suggest it's best to leave the patella alone when:
The patient has good cartilage on the back of the patella.
The patient is young and active.
The patient is not overweight or obese.
The patella moves up and down (tracks) normally over the joint.
There's no sign of inflammation under the patella.
On the other hand some surgeons always replace the patella. Their results are very good. What we really need are some long-term studies that show the results years after the TKR was done. Results for patients with and without patella replacement should be compared.
A recent review of studies between 1996 and 2003 was unable to find any clear-cut ways to decide the issue. Overall it looks like patellar resurfacing (replacement) results in
less pain, fewer reoperations, and greater knee function.