When is knee osteotomy recommended?
Knee osteotomy is used when a patient is in the early stages of osteoarthritis which has resulted in damage on one side of the knee joint. The procedure aims to transfer weight from the arthritic part of the knee to a healthier area, correct poor knee alignment and prolong the life span of the knee joint.
Knee osteotomy preserves your native knee and slows arthritic progression so that the need for a joint replacement may be delayed for years. There are also less restrictions on physical activities after a knee osteotomy and patients are potentially able to participate in sports and high-impact exercises.
However, it is worth noting that the recovery process for a knee osteotomy may be longer and more difficult, and pain relief is not as predictable as compared to a knee replacement. It could also make a future knee replacement surgery more challenging. Nonetheless, knee osteotomy remains a good option for many young, active patients as it preserves the native knee joint, and allows them to maintain an active lifestyle.
Most knee osteotomies are done on the tibia (shinbone) to correct a bowlegged alignment to prevent putting too much stress on the inner portions of the knee.
A wedge of bone needs to remove from the shin bone (tibia) to correct the alignment of the knee. Usually, the wedge of bone is removed from the inside of the tibia, and the space is left “open”. For large spaces, a bone graft is added to fill the space and provide structural support.
This procedure is called an opening wedge high tibia osteotomy, and it helps to transfer weight from the diseased inner portion of the knee to the healthy outer portion of the knee, allowing the knee to carry more weight, ease pressure and relieve pain.
In certain cases, the same effect is achieved when a wedge of bone is removed from the outside of the tibia and the surgeon closes the wedge. This brings the bones on the healthy side of the knee together, a procedure called closing wedge high tibia osteotomy.
Knee osteotomies on the femur (thighbone) are done using the same technique but are usually done to correct a knock-knee alignment to transfer weight from the diseased outer portion of the knee to the healthy inner portion of the knee.
Your orthopaedic surgeon will make an incision around the knee and plan the correct size of the wedge using guide wires. An oscillating saw will then be used to cut along the guide wires to open or close the wedge. Bone graft may be added to an opening wedge osteotomy, followed by the insertion of a plate and screws to hold the bones in place.
Commonly Asked Questions
Planning for the surgery
You will be evaluated by your orthopaedic surgeon on whether you are a suitable candidate for a knee osteotomy. Patients should be able to fully straighten the knee and bend it at least 90 degrees. In addition, the arthritis should be confined to only one part of the knee, rather than involving the whole knee. Your orthopaedic surgeon will help you to determine if a knee osteotomy is suitable for you.
Your orthopaedic surgeon will also recommend consulting your primary doctor or anaesthetist to check your general medical condition and do blood tests, a chest X-ray, and an electrocardiogram to assess your fitness for surgery.
You will most likely be admitted to the hospital on the day of your surgery and most patients get discharged after two to four days.
Consult your orthopaedic surgeon for specific instructions but you may have to stop taking traditional medicine, blood thinning medications and control your general medical conditions before the surgery.
Knee osteotomy is typically performed under general (put to sleep) or spinal (numb from the waist down) anaesthesia, supplemented with nerve blocks or injections of local anaesthetic to reduce pain. Your orthopaedic surgeon and anaesthetist will discuss the best method with you.
A knee osteotomy will typically take between one to two hours.
The chances of complications from a knee osteotomy are low, but as with any kind of surgery, there are risks involved. Common complications include infection, blood clots in the veins, stiffness of the knee joint, injuries to the vessels and nerves, and failure of the osteotomy to heal.
Feeling some pain is part and parcel of the healing process after surgery. Rest assured that your doctor will prescribe medications for short-term pain relief.
Paracetamol, non-steroidal anti-inflammatory drugs, and opioids are common temporary pain relief medications that will be prescribed. Your doctor might also recommend aspirin or other blood thinning medication to reduce the risk of blood clots in the veins.
You will most likely have to use crutches for four to six weeks and your orthopaedic surgeon might put your knee in a brace for protection. Your physical therapist will also give you exercises to help with restoring strength in your knee. Your orthopaedic specialist will do serial X-rays to check for healing of the bone. Most patients can return to work after two to three months and resume sports between six to 12 months.