Knee Society

Knee Osteotomy

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.

Osteotomy is also used as an alternative treatment to total knee replacement in younger and active patients. 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.

Surgery

Depending on where osteoarthritis has damaged your cartilage, an osteotomy removes a wedge of bone from different areas of your shinbone. The most common type of osteotomy performed on arthritic knees is a high tibial osteotomy, which addresses cartilage damage on the inside (medial) portion of your knee.

The following surgery section provides details about the high tibial osteotomy procedure that apply in general to most other osteotomy procedures. The procedure usually takes one to one-and-a-half hours to perform.

During a high tibial osteotomy, surgeons remove a wedge of bone from the outside of your knee, which causes your leg to bend slightly inward. It is like realigning a bowlegged knee to a knock-kneed position. Your weight is transferred to the outside (lateral) portion of your knee where the cartilage is still healthy.

Surgery

After anesthesia is administered, which may be regional, or general, the surgical team sterilizes the leg with antibacterial solution.
Surgeons map out the exact size of the bone wedge they will remove, either using an X-ray, CT scan, or 3D computer modeling.
A four- to five-inch incision is made down the front and outside of your knee, starting below the kneecap and extending below the top of your shinbone.
Guide wires are drilled into the top of your shinbone (tibia plateau) from the outside (lateral side) of your knee. The wires usually outline a triangle form in your shinbone.
A standard oscillating saw is run along the guide wires, removing most of the bone wedge from underneath the outside of your knee, below the healthy cartilage. The cartilage surface on the top of the outside (lateral side) of your shinbone is left intact.
The top of your shinbone is then lowered on the outside and attached with surgical staples or screws, depending on the size of the wedge that was removed.

The layers of tissue in your knee are stitched together, usually with absorbable sutures.

Day Of Surgery

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.

Recovery 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.

Post-Op In Hospital

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.

Rehabilitation

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.

Stretching

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.

Aerobic Exercise

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.

Strengthening

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.

Prevention

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.

The Knee Society Office:
6300 N. River Road, Suite 727, Rosemont, IL 60018-4226
Telephone: (847) 698-1632 Fax: (847) 823-0536
Email: knee@aaos.org