Osteotomies

Overview

High tibial osteotomy (HTO) is a surgical procedure in which the bone at the upper end of the tibia (shin bone) is cut and realigned. It is usually performed in arthritic conditions affecting only one side of your knee and the aim is to take pressure off the damaged area and shift it to the other side of your knee where there is still healthy cartilage. Occasionally, Dr Klar will perform a distal femoral osteotomy to correct knocked-knee deformity. In this case, the osteotomy is made in the distal femur rather than the proximal tibia.

A distal femoral osteotomy (DFO) can be used to straighten the knee when the deformity is mostly in the femur rather than the tibia.

The ideal patient is a less than 60 years old, a non-smoker, has a BMI <40 with knee arthritis localised to the inner half of the affected knee. During the surgery, Dr Klar will add a wedge of bone below the knee joint depending on the site of arthritic damage.

Surgery

Nicotine products of any kind are especially detrimental to the success of High Tibial Osteotomy and Distal Femoral Osteotomy surgery. If you are unable to cease all nicotine products Dr Klar strongly advises you defer the surgery until you can successfully abstain.

High tibial osteotomy is commonly used for patients with osteoarthritis that is isolated to a single compartment (unicompartmental osteoarthritis). It is also performed for treating mechanical axis malalignment, osteochondritis dissecans, posterolateral instability, and chondral resurfacing.

Dr Klar prefers to use a medial opening wedge high tibial osteotomy (MOWHTO) rather than the older technique of a closing wedge osteotomy to correct the axis of the lower limb.

A general anaesthetic is used in most cases. In an opening wedge osteotomy, an incision is made along the tibia 6-8cm in length on the front of the knee. The image intensifier (x-ray machine) is used to determine the correct site for the osteotomy and the cut in the bone is made. The bone is then carefully wedged open the correct amount to exactly realign the lower limb. Dr Klar prefers to fill the gap with wedges of donor bone from a Bone Bank. The osteotomy is then held solidly with a titanium plate and screws. After the procedure is completed, the surgical site is then sutured and closed in layers.

Post operation

Dr Klar recommends that crutches be used for 3 weeks after your surgery. Usually, hinged knee brace will be fitted after the operation and this is worn for 4 weeks on average. Controlled progressive weight bearing is needed on the operated limb as per Dr Klar’s instructions.

You can be discharged from hospital when the pain is controlled with tablets, you can safely ambulate with crutches and you are tolerating a normal diet. This is usually around day 3 after the procedure.

Risks and complications

Following high tibial osteotomy, risks and complications may include:

• Infection
• Skin necrosis
• Non-union (failure of the bones to heal)
• Nerve injury
• Blood vessel injury
• Over or under correction of the mechanical axis of the limb
• Compartment syndrome of the leg
• Deep vein thrombosis or blood clots in the leg or lung
• Complex regional pain syndrome