A tibial osteotomy is a surgical procedure where a wedge of bone is either added to or cut from the tibia, or shin bone, in order to correct osteoarthritis in the knee. Osteoarthritis, also known as osteoarthrosis or degenerative joint disease, is the wearing away of the protective layer of cartilage between the femur and the tibia. Oftentimes, the cartilage damage will be worse on one side of the knee than on the other, resulting in an unnatural alignment of the leg bones. A tibial osteotomy realigns the bones to alleviate pain and undue pressure on the joint.
Alignment of the leg bones is specifically designed to allow the body to support its weight by evenly distributing the pressure. Erosion of cartilage on the inside of the knee, also called the medial compartment, will cause the knee to bow out and away from the body. Damage to the cartilage on the outside of the knee, also called the lateral side, will force the bones inward, resulting in a knock-kneed stance. The more common of these two conditions is the damage to the inside of the knee.
The knee joint can be realigned in one of two ways — either by adding or removing a wedge of bone. These are referred to as closing and opening wedge osteotomies. In a closing wedge tibial osteotomy for bowleggedness, for instance, a wedge of bone is cut and removed from the lateral side and the ends of the remaining bones are brought together. In a opening wedge procedure, a wedge is cut and opened on the medial side, and a bone graft is added to plug the wedge. Both of these methods cause the knee joint to move back toward the inside, thereby reestablishing the correct alignment of the leg bones.
Once the bone has been cut and patched, it is held together with screws and a plate. A tibial osteotomy patient can expect to wear a knee brace until the joint recovers. Physical therapy may also be required to help strengthen the muscles surrounding the knee, thereby aiding in a faster recovery.
A tibial osteotomy is a procedure designed to help make use of the healthy part of the knee joint. It may increase the length of time a patient can continue to be comfortably mobile, but it may not be the final solution to the problem. Continued degeneration of the cartilage may eventually make a knee replacement necessary.