An osteotomy is a surgical operation where a bone is cut to shorten, lengthen, or change its alignment.
Osteotomies tend to be performed in younger patients to improve symptoms and help delay or prevent the need for an artificial joint replacement.
Osteotomies are performed to change the way forces pass through the joint. They are used to try and move pressure away from damaged parts of the knee to help protect them. They are usually performed in the lower femur (thigh bone) or upper tibia (shin bone). After cuts have been made, the bone is carefully repositioned using x-ray guidance and then the new position fixed with metal plates and screws. Occasionally osteotomies are used to help protect damaged ligaments and help improve knee stability.
Following surgery most patients are ready to go home within 48hours. The plate and screws are made of titanium and are very strong so you can partially bear weight on the operated leg straight away with the help of crutches. It is normal for the operated leg to be rather swollen and bruised for several weeks after this procedure. Regular icing, elevation and a gentle range of movement exercises are used to help reduce the swelling and pain.
After six weeks, if the x-rays show the bone is healing well you can progress to full weight bearing and dispense with your crutches as the discomfort settles. It usually takes many months for the osteotomy site to fully heal and for the leg pain to completely settle. Occasionally the metal plates securing the osteotomy may need to be removed once the bone has healed as they may cause irritation.
Risks include:
- deep vein thrombosis (DVT) and pulmonary embolus. A combination of surgery, immobilisation of the limb, smoking and the oral contraceptive pill or hormonal replacement therapy all multiply to increase the risk of a blood clot. Any past history of blood clots should be brought to the attention of the surgeon prior to your operation. The oral contraceptive pill, hormonal replacement therapy and smoking should cease one week prior to surgery to minimise the risk. Blood thinning injections will be given following your surgery to help reduce the chance of developing a clot
- excessive bleeding resulting in a haematoma is known to occur with patients taking aspirin or anti-inflammatory drugs. They should be stopped at least one week prior to surgery
- infection. Surgery is carried out under strict germ free conditions in an operating theatre. Antibiotics are administered intravenously at the time of your surgery. Any allergy to any known antibiotics should be brought to the attention surgeon or anaesthetist. Despite these measures, following surgery there is a less than 3% chance of developing an infection. Most commonly these are superficial wound infections that resolve with a course of antibiotics, however more serious infections may require further hospitalisation and treatment
- nerve injury. Injury to the peroneal nerve can occur in patients following knee osteotomy. This may result in sensory loss or muscle weakness in the lower leg. Very rarely this weakness may be permanent and lead to a ‘foot-drop’ problem
- injury to the blood vessels around the knee during surgery is a very rare complication (less than 1%)
- delayed or non-union of the osteotomy site may occur in 2 to 4% of cases. Further surgery may be required if this occurs. The risk of non-union is far higher in smokers and this type of surgery is generally contra-indicated in people who smoke
- further surgery. Over time the ‘healthy’ areas of the knee joint may also wear out and become arthritic. In this situation a total knee replacement is usually needed. Total knee replacement following a knee osteotomy is a technically more difficult procedure than if no osteotomy has been performed
