Knee osteotomy is a surgery that can be performed instead of a total knee replacement to correct the weight-bearing forces in an unbalanced knee joint. But it is only the right choice for specific patients.
In patients with degenerative arthritis, or osteoarthritis, of the knee joint, deformities of the knee are common. These deformities include a bow-legged or knock-kneed appearance. More technically, these deformities are called genu varum (bow-legged) or genu valgum (knock-kneed).
As arthritis progresses, the cartilage of the joint wears thin. The meniscus, or joint cushions, are also damaged and wear away. If the damage is more on one side of the joint than the other, as is usually the case, then the knee will take on a deformed appearance. When the inside, or medial side, of the joint is worn thin, a varus deformity (bow-legged) will result. When the outside, or lateral side, of the joint wears thin, a valgus deformity results (knock-knees).
When the knee is worn more on one side, the forces transmitted across the joint are altered. When the inside (medial side) wears thin, the force of your body weight becomes more centered on the worn out part of the joint. Therefore, the healthier part of the knee is spared the burden of your body weight, and the damaged portion gets the brunt of your weight. This becomes a vicious cycle that leads to the progression of arthritis.
An osteotomy uses is a procedure where the surgeon cuts the bone and then reorients the bone. There are two basic types of osteotomies: closing wedge, where a wedge of bone is removed to change the alignment of the bone; and, opening wedge, where the bone is gapped open on one side to realign the bone. Depending on the type of deformity and the location of your osteotomy, your surgeon will choose one of these options.
Once the bone is cut and subsequently realigned, your surgeon may choose to use a metal plate and screws to hold the bones in the new position.
The recovery from a knee osteotomy can be difficult. Because the bone is cut, it needs time to heal. The total healing time is at least 8 weeks and can take longer. Most patients need physical therapy to regain their knee motion.
Hospital discharge. In most cases, patients go home 1 to 2 days after an osteotomy.
Pain management. After surgery, you will feel some pain, but your surgeon and nurses will make every effort to help you feel as comfortable as possible.
Many types of pain medication are available to help control pain, including opioids, nonsteroidal anti-inflammatory drugs (NSAIDs) and local anesthetics. Treating pain with medications can help you feel more comfortable, which will help your body heal faster and recover from surgery faster.
Opioids can provide excellent pain relief, however, they are a narcotic and can be addictive. It is important to use opioids only as directed by your doctor. You should stop taking these medications as soon as your pain starts to improve.
Weight bearing. After the operation, you will most likely need to use crutches for several weeks. Your surgeon may also put your knee in a brace or cast for protection while the bone heals. Your surgeon will give you instructions about when weight bearing can begin.
Knee osteotomy is most effective for thin, active patients who are less than 60 years old. Good candidates have pain on only one side of the knee, and no pain under the kneecap. Knee pain should be brought on mostly by activity, as well as by standing for a long period of time.
Candidates should be able to fully straighten the knee and bend it at least 90 degrees. Patients with rheumatoid arthritis are not good candidates for osteotomy. Your orthopaedic surgeon will help you determine whether a knee osteotomy is suited for you.