Tibia osteotomy – Knee wedge surgery

By Lars Blønd

This is a knee surgery that shifts the load away from the side of the knee that is worn and painful. By distributing the load to the healthy side of the knee, you can become close to pain-free.

Wedge surgery

Tibial osteotomy is a so-called knee-preserving surgery. This refers to an operation without printing anything in the knee. Wedge surgery involves either inserting or removing a wedge in the tibia. What determines this is primarily whether you are bow-legged or calf-kneed. If you have osteoarthritis (osteoarthritis as it is known today), you basically have a thinning of the cartilage. Cartilage is the sliding layer that covers the bone. For partly unknown reasons, the cartilage has deteriorated and thinned out. Osteoarthritis affects the inner femur bone in bow-legged people and the outer femur bone in calf-kneed people. If you’re up for it and curious, you can read more about knee osteoarthritis here.

The principle behind wedge surgery

By far the most common is osteoarthritis on the inside of the knee. That’s why there’s pain on the inside. This is usually because you are bow-legged. This can be remedied with a tibial osteotomy. It’s the other way around if the osteoarthritis is on the outside and you’re a calf knee. Wedge surgery corrects the angle in your knee. This is done by inserting a wedge into the bone at the top of the tibia. This causes the load in your knee to shift to the healthy side of your knee.

How long does it last?

It has been shown that the thinning cartilage rebuilds completely or partially after a few years. What you can achieve with this surgery is a reduction in knee pain. Hopefully you can resume your sport too. The timing of when you will need a knee replacement is postponed. Today we know that after 15 years, 68% of knees still hold up – read more here. The earlier you do it, the longer it lasts. Before your surgery, special X-rays of your leg will be taken. This is so that the exact angle for the alignment can be measured. Critics of this type of surgery said that the outcome of any subsequent knee replacement would be worse if a tibial osteotomy was performed first. Today, we know that there is no longer any evidence for this. Here’s a comparison in durability between half knee replacements (unicorn knee) and tibial osteotomy read here

Avoid surgery

A temporary alternative to surgery can be an unloader bandage. In addition, you can go through something called GLA:D training. Learn how to use your knee properly while following an exercise program. An unloader splint is used during the time of day when you put stress on your knee. The idea behind the splint is a built-in spring that helps you relieve pressure on the side of the knee where the osteoarthritis is located. The price is between 3000 – 15,000 kr. Watch the video here

Link to a model that can be worn under pants

Wheel bone – Drawing and X-ray image

You can see that the load line goes through the inner side of the knees. The image is called a “long film”, “leg length measurement” or a “spot measurement”

What about the surgery itself

The surgery opens up the inside of the knee/shin and using a special guide system, the tibia is sawed 3/4 through and a plastic wedge is inserted to correct the angle. The leg will be about ½ cm longer due to the wedge. The plastic wedge is screwed in place with plastic screws, all made from a material similar to bone and does not need to be removed again. See figure. The iBalance method is about 10 years old, is very safe and accurate and has many advantages over using a metal rail, for example. In some cases, in conjunction with the above surgery, the knee will also be operated on using a scope.

After surgery

You will come to the recovery room after the surgery, where I will inform you about the progress of the surgery. You will be given a copy of the operation description before discharge.

Local anesthesia and pain

During the surgery, I will place a local anesthetic in your knee joint, which lasts for a few hours and the anesthesiologist may also place an additional nerve block. It’s normal for your knee to hurt quite a bit in the first few weeks. To relieve the pain, place an ice pack wrapped in a towel on your knee for 20 minutes at a time.

After discharge

You will be fitted with a brace that allows you to bend your knee and you will need to wear the brace for 8 weeks. The purpose of the splint is to protect the bone from fractures until the bone has healed. After 14 days, it is safe to open the rail when sitting on a sofa. After 4 weeks you can take the splint off for sleeping and bathing, the first 2 weeks you can support a maximum weight load of 5 kg and after 2 weeks you can support about 20-40 kg. After 4 weeks, you can support full weight.

Special conditions

You should expect some swelling of the lower leg, ankle and foot in the first few weeks after surgery. It is important to keep the leg elevated to avoid too much blood being drawn on the leg. By keeping your leg elevated for the first few days, you can prevent major blood draws in the leg that lead to water blisters and fever in the first 24 hours.

Smoking

A special issue with this surgery is that you must stop smoking at least 2 weeks before and at least 2 weeks after. If you don’t stop, there is a high risk that the bone will not heal.

Medication after surgery

Some people initially experience burning, which can be relieved with an ointment containing arthritis medication (available over the counter). You will need to take a pill every day for the first 10 days after surgery to prevent deep vein inflammation. If you experience side effects to the pills such as nosebleeds or excessive bruising, you should only take the pill every other day. After surgery, most people take strong painkillers such as morphine. Morphine tends to cause constipation, so it’s a good idea to prevent constipation by taking laxative medication. You should also expect to experience numbness in a palm-sized area of the lower leg. In rare cases, you may experience foot pain for about 2 weeks after surgery.

Rehabilitation

After surgery, you will be referred to rehabilitation, which typically starts 14 days after surgery and aims to restore mobility in the knee and rebuild the muscles in the leg and restore balance. Your life will be complicated for a period of time and you will have difficulty getting around with crutches, especially in the first 2 weeks, because you are not allowed to support yourself. You can only resume driving when you can drive safely in relation to your leg. This is typically 4 weeks after surgery, although slightly sooner for the left leg than the right. 12-14 days after surgery, you will need to have the stitches removed by your doctor. You will need an X-ray 4 weeks after surgery and a check-up with me. The next X-ray check-up is 2-3 months later. It is not uncommon for the knee to take many months to settle down after surgery.

Complications

Inflammation may occur after the procedure. It happens very rarely, but is serious and needs to be treated. In rare cases, the osteotomy does not heal and needs to be operated on again.

Left knee 3 months after a tibia osteotomy and “holes” in the bone are where the plastic wedge is located and the white in the bone is artificial bone that will eventually turn into regular bone

Tibia osteotomy and cruciate ligament reconstruction

This tibia osteotomy surgery can also be combined with a cruciate ligament reconstruction. In situations where there is both osteoarthritis of the knee and loose knee, both surgeries are performed at the same time. In very specific situations, it may be necessary to correct the knee’s inclination (tibia slope) before ACL reconstruction. Read more
here

Femoral osteotomy

Sometimes the misalignment in the knee is not in the tibia, but in the femur. In these cases, the wedge surgery is performed on the femur. This is called a femoral osteotomy. Here, wedge surgery is performed with a splint that is attached with screws. This splint must remain in place until the bone has healed properly. Typically, however, the splint is left in place for 1 year and it is almost always necessary to remove the splint as it is a nuisance.

For rotational osteotomies of the femur and tibia, splints are also used

Image shows calf knee and bow leg

Am I bow-legged?

Sometimes it’s obvious whether you’re bow-legged or calf-kneed. Sometimes even the trained eye can’t see it. A spot measurement is an X-ray image, as shown above. Here the degree of misalignment can be precisely measured.

Why wedge surgery?

Why choose a tibial osteotomy instead of a new knee or half knee? Firstly, it’s a knee-preserving surgery. This means that nothing is replaced. Firstly, a “new knee” is not a new knee, but a combination of metal and plastic. One is a knee replacement and a major surgery. Today, unlike in the past, the results after tibial osteotomy seem to be better than with a knee prosthesis. Overall, 20% will be very satisfied, 70% will be satisfied and 10% will be dissatisfied. The 10% will need a knee prosthesis.

For geeks – benefits of Ibalance

Why Ibalance tibia osteotomy and not splint osteotomy. Ibalance is a more modern method that is precise. The advanced guide system and peek wedge help make the operation very precise. The guide system also protects the blood vessels and nerve in the popliteal fossa. In addition, the system is built around a so-called “hingepin” which reduces the risk of fractures during surgery. The final benefit is that there are no implants that need to be removed later because they’re in the way. In some situations, however, it is not possible to use Ibalance and a splint-based osteotomy must be used.

What’s better – half a new knee or a wedge surgery.

According to this study of 108,000 patients, it seems that wedge surgery is better
click here to read it

This is an MRI scan of a knee before surgery where there is incipient osteoarthritis on the inside. There is a so-called bonebruise on the inner shin bone (right in the picture). Bonebruise is a swelling in the bone and associated with pain. See image below.

The picture shows the same knee as seen above. A tibial osteosteotomy has now been performed. An Ibalance wedge is inserted so that the pressure is now placed on the outer part of the knee. As a result, the bonebruise that was seen in the pre-surgery image is now gone. The patient recovered and had surgery on the other knee as well.

Tibia osteotomy – iBalance

This shows a picture before and 1 month after tibia osteotomy on the same left leg. The transparent area is the plastic wedge, which is not visible on an X-ray.

Scientific study

We performed on a

research project

to investigate if the technique I use is okay. I initially had the feeling that the correction that was made was not enough. As it turned out, it wasn’t all good and some became a bit bow-legged again. Thankfully, those who got a bit bow-legged again fared just as well as those who maintained the correction. If you look at the article, it looks like there is a high failure rate, but that’s only in relation to the x-ray and not whether the patients were doing well. However, it was not entirely satisfactory that the patients became partially bow-legged again and I found the cause and had it adjusted, so the problem disappeared and it hasn’t been there since.