Knee osteotomy is a surgical procedure that your doctor might recommend if you have arthritis damage in just one area of your knee. Osteotomy is also performed in combination with other types of knee surgery, such as cartilage surgery, if your leg is bowed or knock-kneed.

The procedure involves removing or adding a wedge of bone to your shinbone (tibia) or thighbone (femur) to help shift your body weight off the damaged portion of your knee joint.

Knee osteotomy is most commonly performed on people who are younger than 60 who are active. Many people who undergo this procedure for arthritis might need a total knee replacement — usually about 10 to 15 years after the knee osteotomy.

Slick cartilage covers the ends of the bones in a healthy knee and this allows the bones to move smoothly against each other. Osteoarthritis damages and wears away the cartilage — creating a rough surface.

When the cartilage wears unevenly, it narrows the space between the femur and tibia, causing the knee to bow inward or outward, depending on which side of the knee is affected. Removing or adding a wedge of bone in your upper shinbone or lower thighbone can help straighten the bowing, shift your weight to the undamaged part of your knee joint and prolong the life span of the 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
• Incomplete pain relief

Your surgeon will study X-rays of your knee to determine if osteotomy is appropriate and how much correction of the deformity is needed.

Because you'll be receiving anesthesia, you can't eat or drink before the procedure. If you take daily medications, follow your surgeon's instructions on whether to take them the morning of your surgery.

During the procedure

You'll either be put to sleep (general anesthesia) or be numbed from the waist down (spinal anesthesia). Your surgeon will make an incision over the area of bone to be remodeled.

Depending on the location of the damage, the surgery might involve your shinbone or your thighbone. The most common form of knee osteotomy involves the shinbone.

In the simplest knee osteotomy, your surgeon cuts almost across the bone, opens a gap, fills it with bone graft and fixes the bone in place with a plate and screws. This is called an opening wedge osteotomy.

Another option is to cut the shinbone or thighbone, then remove a wedge of bone. The cut edges of the bone are brought together and held in place with metal hardware. This is called a closing wedge osteotomy.

The surgery typically takes one to two hours.

After the procedure

Depending on the complexity of the surgery and how well you recover, you'll go home the same day or stay one night in the hospital. You'll need to use crutches for approximately two months for your bone to heal properly.

Rehabilitation can take as long as six months. It 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 support the bone while it heals.

In most cases, knee osteotomy relieves arthritis pain and postpones the need for a total knee replacement by 10 to 15 years.