Osteotomy literally means “cutting of the bone.” In a knee osteotomy, either the tibia (shinbone) or femur (thighbone) is cut and then reshaped to relieve pressure on the knee joint.
Knee osteotomy is commonly used to realign your knee structure if you have arthritic damage on only one side of your knee. The goal is to shift your body weight off the damaged area to the other side of your knee, where the cartilage is still healthy. When surgeons remove a wedge of your shinbone from underneath the healthy side of your knee, the shinbone and thighbone can bend away from the damaged cartilage.
Imagine the hinges on a door. When the door is shut, the hinges are flush against the wall. As the door swings open, one side of the door remains pressed against the wall as space opens up on the other side. Removing just a small wedge of bone can “swing” your knee open, pressing the healthy tissue together as space opens up between the thighbone and shinbone on the damaged side so that the arthritic surfaces do not rub against each other.
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 younger than 55 than in people older than 70. Because prosthetic knees may wear out over time, an osteotomy procedure can enable younger, active osteoarthritis patients to continue using the healthy portion of their knee. The procedure can delay the need for a total knee replacement for up to ten years.
Why it’s done
Slick cartilage allows the ends of the bones in a healthy knee to move smoothly against each other. Osteoarthritis damages and wears away the cartilage — creating a rough surface.
When the cartilage wears away unevenly, it narrows the space between the femur and tibia, resulting in a 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 this bowing, shift your weight to the undamaged part of your knee joint and prolong the life span of the knee joint.
Osteoarthritis can develop when the bones of your knee and leg do not line up properly. This can put extra stress on on either the inner (medial) or outer (lateral) side of your knee. Over time, this extra pressure can wear away the smooth cartilage that protects the bones, causing pain and stiffness in your knee.
(Left) A normal knee joint with healthy cartilage. (Right) Osteoarthritis that has damaged just one side of the knee joint.
Advantages and Disadvantages
Knee osteotomy has three goals:
- To transfer weight from the arthritic part of the knee to a healthier area
- To correct poor knee alignment
- To prolong the life span of the knee joint
By preserving your own knee anatomy, a successful osteotomy may delay the need for a joint replacement for several years. Another advantage is that there are no restrictions on physical activities after an osteotomy – you will be able to comfortably participate in your favorite activities, even high impact exercise.
Osteotomy does have disadvantages. For example, pain relief is not as predictable after osteotomy compared with a partial or total knee replacement. Because you cannot put your weight on your leg after osteotomy, it takes longer to recover from an osteotomy procedure than a partial knee replacement.
In some cases, having had an osteotomy can make later knee replacement surgery more challenging.
The recovery is typically more difficult than a partial knee replacement because of pain and not being able to put weight on the leg.
Because results from total knee replacement and partial knee replacement have been so successful, knee osteotomy has become less common. Nevertheless, it remains an option for many patients.
Most osteotomies for knee arthritis are done on the tibia (shinbone) to correct a bowlegged alignment that is putting too much stress on the inside of the knee.
During this procedure, a wedge of bone is removed from the outside of the tibia, under the healthy side of the knee. When the surgeon closes the wedge, it straightens the leg. This brings the bones on the healthy side of the knee closer together and creates more space between the bones on the damaged, arthritic side. As a result, the knee can carry weight more evenly, easing pressure on the painful side.
In a tibial osteotomy, a wedge of bone is removed to straighten out the leg.
Tibial osteotomy was first performed in Europe in the late 1950s and brought to the United States in the 1960s. This procedure is sometimes called a “high tibial osteotomy.”
Osteotomies of the thighbone (femur) are done using the same technique. They are usually done to correct a knock-kneed alignment.
Candidates for Knee Osteotomy
Knee osteotomy is most effective for thin, active patients who are 40 to 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 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.
At most medical centers, you will go to “patient admissions” to check in for your outpatient arthroscopic surgery.
After you have checked in to the hospital or clinic, you will go to a holding area where the final preparations are made. The paperwork is completed and your knee area may be shaved (this is not always necessary). You will wear a hospital gown and remove all of your jewelry.
You will meet the anesthesiologist or anesthetist (a nurse who has done graduate training to provide anesthesia under the supervision of an anesthesiologist). Then, you will walk or ride on a stretcher to the operating room. Most patients are not sedated until they go into the operating room.
Here are some important steps to remember for the day of your surgery:
- You will probably be told not to eat or drink anything after midnight on the night before your surgery. This will reduce the risk of vomiting while you are under general anesthesia.
- Wear a loose pair of shorts or sweatpants that will fit comfortably over your knee bandage when you leave the hospital.
Take it easy. Keeping a good frame of mind can help ease any nerves or anxiety about undergoing surgery. Distractions such as reading, watching television, chatting with visitors, or talking on the telephone can also help.
A knee osteotomy operation typically lasts between 1 and 2 hours.
Your surgeon will make an incision at the front of your knee, starting below your kneecap. He or she will plan out the correct size of the wedge using guide wires. With an oscillating saw, your surgeon will cut along the guide wires, and then remove the wedge of bone. He or she will “close” or bring together the bones in order to fill the space created by removing the wedge. Your surgeon will insert a plate and screws to hold the bones in place until the osteotomy heals.
This is the most commonly used osteotomy procedure, and is called a closing wedge osteotomy.
After the wedge of bone is removed, the tibia may be held in place with a plate and screws.
In some cases, rather than “closing” the bones, the wedge of bone is “opened” and a bone graft is added to fill the space and help the osteotomy heal. This procedure is called an opening wedge osteotomy.
After the surgery, you will be taken to the recovery room where you will be closely monitored as you recover from the anesthesia. You will then be taken to your hospital room.
Following a knee osteotomy, you usually stay in the recovery room for at least two hours while the anesthetic wears off.
This procedure typically causes significant pain. You will be given adequate pain medicine, either orally or through an IV (intravenous) line, as well as instructions for what to do over the next couple of days.
Your knee will be bandaged and may have ice on it. You may have significant pain early on and you should take the pain medicine as directed. Remember that it is easier to keep pain suppressed than it is to treat pain once it becomes present, so ask the nurse for medication when you feel pain coming on.
You should try to move your feet and ankles while you are in the recovery room to improve circulation.
Your temperature, blood pressure, and heart rate will be monitored by a nurse, who, with the assistance of the doctor, will determine when you are ready to leave the hospital or, if necessary, be admitted for an overnight stay. Most patients remain in the hospital for two to four days following an osteotomy.
After knee osteotomy, you usually are taken to a hospital room where nurses, anesthesiologists, and physicians can regularly monitor your recovery. Most patients spend two to four days recovering in the hospital.
As soon as possible after surgery is completed, you will begin doing continuous passive motion exercises while in bed. Your leg will be flexed and extended to keep the knee joint from becoming stiff.
This may be done using a continuous passive motion (CPM) machine. The CPM is attached to your bed and then your leg is placed in it. When turned on, it takes your leg through a continuous range of motion.
There will likely be pain, and you can expect to be given pain medication as needed. Ice also helps control pain and swelling.
For two or three days after surgery, you may experience night sweats and a fever of up to 101. Your physician may suggest acetaminophen, coughing, and deep breathing to get over this. This is common and should not alarm you. The incision usually starts to close within six days and the bandage can be removed. Physicians commonly fit you with a knee brace that may allow a limited range of movement and helps push your knee into the correct position. For a high tibial osteotomy, the knee brace pushes your knee inward, making you slightly more knock-kneed. Please note that some surgeons will cast your knee for 4 to 6 weeks to ensure that the osteotemy heals.
You may be able to put some weight on your knee, but physicians usually prescribe crutches for at least six weeks. You will be given a prescription for pain medication and usually schedule a follow-up visit sometime around six weeks after surgery.
You will most likely need to use crutches for several weeks.
About 6 weeks after the operation, you will see your surgeon for a follow-up visit. X-rays will be taken so that your surgeon can check how well the osteotomy has healed. After the follow-up, your surgeon will tell you when it is safe to put weight on your leg, and when you can start rehabilitation.
During rehabilitation, a physical therapist will give you exercises to help maintain your range of motion and restore your strength.
You may be able to resume your full activities after 3 to 6 months.
Most patients can begin physical therapy around six to eight weeks after surgery. Unlike other surgical treatments for arthritis, osteotomy relies on bone healing before more vigorous, weight bearing exercises in the gym can begin. In the best scenario, people respond to strengthening exercises and stop wearing the brace after the first three to six months of therapy.
Light exercise is one of the most effective ways to relieve arthritis pain by stimulating circulation and strengthening the muscles, ligaments, and tendons around your knee. Strong muscles take pressure off the bones so there is less grinding in the knee joint during activities. In conjunction with a healthy diet, exercise can also help you lose weight, which takes stress off your arthritic knee.
In the first few weeks of rehabilitation, your physical therapist usually helps you stretch the muscles in the hamstrings, quadriceps, and calves while flexing and extending your knee to restore a full, pain-free range of motion.
When pain has decreased, physicians generally recommend at least 30 minutes a day of low-impact exercise a day for patients with arthritis. You should try to cut back on activities that put a pounding on your knees, like running and strenuous weight lifting.
Cross-training exercise programs are commonly prescribed when you have arthritis. Depending on your preferences, your workouts may vary each day between cycling, cross-country skiing machines, elliptical training machines, swimming, and other low-impact cardiovascular exercises. Walking is usually better for arthritic knees than running, and many patients prefer swimming in a warm pool, which takes your body weight off your knees and makes movement easier.
Strength training usually focuses on moving light weights through a complete, controlled range of motion. You should generally avoid trying to lift as much as possible with your quadriceps and hamstrings. Your physical therapist typically teaches you to move slowly through the entire movement, like bending and straightening your knee, with enough resistance to work your muscles without stressing the bones in your knee.
Once your physical therapist has taught you a proper exercise program, it is important to find time each day to perform the prescribed exercises.
Recovery at Home
You will likely feel pain or discomfort for the first week at home after an osteotomy, and you will be given a combination of pain medications as needed. A prescription-strength painkiller is usually prescribed and should be taken as directed on the bottle.
Swelling in your leg usually decreases over a span of three to six months after surgery. There may be some minor bleeding for a few days, but by the time you are released from the hospital, most bleeding should have stopped. If you notice an increase in swelling or bleeding, you should call your physician.
Physicians generally recommend that you avoid putting stress on your knee until the bones have healed. Putting weight on your knee too early may damage the bone surface and prolong healing time.
Here is what you can expect and how you can cope after an osteotomy:
- Icing your knee for 20 or 30 minutes a few times a day during the first week after an osteotomy will help reduce pain. Ice therapy may need to intermittently continue for a few months if pain bothers you.
- As much as possible, you should keep your knee elevated above heart level to reduce swelling and pain. It often helps to sleep with pillows under your ankle.
- Immobilize your knee in the prescribed, hinged knee brace for about six weeks. You may remove the brace for brief periods to perform passive motion exercises with the aid of a physical therapist or a CPM machine. Range of motion exercises are important for healing. Regaining full extension is just as important as bending your knee.
- Your leg may appear slightly bent after the surgery as it heals into its new alignment.
- Most patients have to keep the incision dry for seven to ten days. Your physician can recommend a surgical supply store that sells plastic shower bags. Wait until you can stand comfortably for 10 or 15 minutes at a time before you take a shower.
- Crutches or a cane may be needed for between six and ten weeks, depending on the pain. It is difficult to describe the amount of pain any given patient will experience.
- Six weeks after surgery, your physician usually gives you a check-up. X-rays can determine how your bones are healing and whether you are ready to begin rehabilitation.
You may have to take between six weeks and six months off from work, depending on how much you rely on your knee to perform your job.
After rehabilitation, preventing osteoarthritis is a process of slowing the progression and spread of the disease. Because patients remain at risk for continued pain in their knees after treatment, it is important they are proactive about managing their conditions.
A fall or torque to the leg during the first two months after surgery may jeopardize the healing of your bones. You should exercise extreme caution during all activities, including walking, until your physician determines that your bones have healed.
Maintaining aerobic cardiovascular fitness has been an effective method for preventing the progression of osteoarthritis. Light, daily exercise is much better for an arthritic knee than occasional, heavy exercise.
When you have arthritis in your knees, it is especially important to avoid suffering any serious knee injuries, like torn ligaments or fractured bones, because arthritis can complicate knee injury treatment. You should avoid high-impact or repetitive stress sports, like football and distance running, that commonly cause severe knee injuries. Depending on the severity of your arthritis, your physician may also recommend limiting your participation in sports that involve sprinting, twisting, or jumping.
Because osteoarthritis has multiple causes and may be related to genetic factors, no simple prevention tactic will help everyone avoid increased arthritic pain. To prevent the spread of arthritis, physicians generally recommend that you take the following precautions:
- Avoid anything that makes pain last for over an hour or two.
- Perform controlled range of motion activities that do not overload the joint.
- Avoid heavy impact on the knees during everyday and athletic activities.
- Gently strengthen the muscles in your thigh and lower leg to help protect the bones and cartilage in your knee.
Non-contact activities are a great way to keeping joints and bones healthy and maintain fitness over time. Exercise also helps promote weight loss, which can take stress off your knees.