The knee is one of the largest joints in the body. A healthy knee moves your lower leg forward and back and rotates it slightly as well. When it comes time to replace this joint due to some form of arthritis, Dr. Caillouette has two options for total knee replacement. One is called a fixed bearing knee and the other, a rotating platform. The fixed bearing knee has been clinically used in total knee replacements for more than three decades and has very good long-term results. In a quest for even longer-lasting knees, the rotating platform has been developed.   This knee has been implanted for a shorter period of time than the traditional fixed bearing and differs in that it rotates slightly.
For patients that are younger, more active and have health supporting tissues, a Rotating Platform implant may be selected to enhance longevity of the implant.

The right design for you depends on your age, health status and the condition of your knee. Dr. Caillouette performs both types of knee replacements and wants you to know about both designs.

A rotating platform knee has four main parts:

The tibial component replaces the top of the shinbone (tibia). In a rotating platform knee, this tibial component is a metal tray that covers the end of the tibia.

The tibial insert fits into the tibial component and lies at the point where the tibia and femur (thigh bone) meet. This insert is disk-shaped and made of a very strong plastic called polyethylene. It sits on a highly polished surface and rotates around a conical post.

The femoral component replaces the two femoral condyles, the bony ridges at the end of the femur, and the groove in the femur where the patella runs.

The patellar component replaces the bone surface on the top of the patella (kneecap) that runs in a groove along the bottom of the thighbone.

Action that more closely imitates your natural knee

What sets the rotating platform knee apart is the polyethylene insert. This is a bearing surface that allows the tibial and femoral parts of the knee to move together. The polyethylene insert between the femur and tibia will rotate as the knee moves, creating a more natural, joint-like motion.

This rotation spreads the contact more evenly between the two parts, reducing the stress of everyday activities on the implant.  When the knee implant bends and rotates during activity, the polyethylene can wear.  A rotating platform knee is designed to reduce the stresses in the knee that can lead to polyethylene wear.  This may increase the longevity of the implant.


Compared to fixed bearing knees, rotating platform knees are less forgiving of imbalance in soft tissues. There is an increased risk of dislocation and your health must be taken into consideration. Therefore, Dr. Caillouette must evaluate your knee for many things before making a recommendation on the type of knee to use in surgery.