You are ahead of the game by even knowing to ask the question! Most people don’t realize that a total knee replacement can involve three component parts. There is the femoral side of the joint (the bottom portion of the femur or upper thigh bone). Then there is the tibial side of the joint (the upper part of the tibia or lower leg bone). Those two components make up the main knee joint as we think about it.
But there is a third piece and that’s the patella (knee cap). The patellofemoral joint (patella sliding and gliding up and down over the front of the knee) is an important part of the entire knee complex. Resurfacing means the back of the patella is lined with a polyethylene (plastic) dome to allow it to move freely and smoothly once again.
There is considerable debate among orthopedic surgeons about the benefits and disadvantages of patellar resurfacing — what you refer to as the pros and cons. The first and most important advantage was just stated: removing any uneven areas, pits, and divets along the back of the knee cap will help it slide and glide more freely up and down over the knee.
If there isn’t a significant amount of degenerative changes along the back of the patella, then this procedure may not be needed. It does take more time in surgery and the risks of complications and/or problems (e.g., bleeding, infection, blood clots, nerve damage) can increase as a result.
But studies comparing outcomes of resurfacing versus nonresurfacing really don’t show any difference between the two groups. Knee pain, motion, and function are reportedly similar when comparing patients with and without patellar resurfacing after knee replacement.
The only statistically significant difference between the two groups appears to be a much higher rate of reoperation in the nonresurfaced group. Most of these second surgeries are done because of knee pain. There is no clear proof that continued knee pain in patients who do not have patellar resurfacing is really due to lack of patellar resurfacing.
Some patients who have patellar resurfacing do have additional surgery because of complications. But studies show the rate is much lower in the resurfacing group compared with the nonresurfacing patients.
There are many variables to consider when trying to compare something like patellar resurfacing versus not resurfacing. For example, there are different designs of knee implants to choose from, differences in surgeon experience, and many different surgical techniques.
In the end, the decision to resurface (or not resurface) the patella as part of the knee replacement must be made together by the patient and surgeon. Surgeons must keep up with the results of current studies in order to consider all the current evidence available when advising and counseling patients individually.