Knee osteotomy is a surgical procedure that may be recommended if you have arthritis damage in just one area of your knee. In knee osteotomy, a surgeon removes or adds a wedge of bone to your upper shinbone (tibia) or lower thighbone (femur). This helps shift your body weight off the damaged portion of your knee joint.
Knee osteotomy is most commonly performed on people who may be considered too young for a total knee replacement. Total knee replacements wear out much more quickly in people under the age of 55 than in people over the age of 70.
Many people who undergo knee osteotomy will eventually need a total knee replacement — usually about 10 to 15 years after the knee osteotomy.
Why it's done
Slick cartilage allows the ends of the bones in a healthy knee to move smoothly against each other. In osteoarthritis, this cartilage is damaged and worn away — creating a rough surface.
The lower portion of the thighbone has two knobs that move against the flatter surface of the top of the shinbone. If arthritis damage affects only one of these knobs, it can make your knee uneven — causing it to bow inward or outward. Removing or adding a wedge of bone in your upper shinbone or lower thighbone can help straighten out this bowing and shift your weight to the undamaged part of your knee joint.
Risks of knee osteotomy may include:
- Infection in the bone or in the surrounding soft tissues
- Failure of the pieces of bone to knit together
- Injuries to nerves or blood vessels around the knee
How you prepare
Before surgery, your surgeon will obtain X-rays and determine if an osteotomy is appropriate and how much correction of the deformity is planned.
Because you'll be receiving anesthesia, you'll need to refrain from eating or drinking before the procedure. If you take daily medications, follow your surgeon's instructions on whether to take them the morning of your surgery.
What you can expect
During the procedure
After you are anesthetized, your surgeon will make an incision over the area of bone to be remodeled. Depending on the severity and the location of the arthritis damage within your knee, the surgery may involve your shinbone or your thighbone. The most common form of knee osteotomy involves the shinbone.
In the simplest variety of knee osteotomy, your surgeon removes a wedge of bone. The cut edges of the bone are brought together and fastened in place with metal hardware. Another option is to cut the shinbone or thighbone and then insert a wedge of bone, which may be taken from your pelvis or from a bone bank. Metal hardware secures the pieces together.
After the procedure
Depending on the complexity of the surgery and how well you recover, you might stay in the hospital for a night or two. You'll need to use crutches for approximately two months so that your bone will heal properly. Rehabilitation may take as long as six months and will include exercises designed to:
- Strengthen your thigh muscles (quadriceps)
- Increase your knee's range of motion
- Improve your balance
Occasionally a brace is used to give additional support to the bone while it is healing.
In most cases, knee osteotomy relieves arthritis pain and postpones the need for a total knee replacement by 10 to 15 years.