Osteotomy literally means “cutting of the bone”. In knee osteotomy either the tibia (shin bone) or femur (thigh bone) is cut and then realigned in order to relieve the pressure on the arthritic part of the knee joint.
Malalignment of the the knee joint can result in excessive loading on either the inner (medial) or outer (lateral) part of the knee. With time this overloading can result in wearing away of the articular cartilage lining the joint and the development of osteoarthritis which in time results in pain and stiffness of the joint.
Where there is malalignment and the osteoarthritis is on the outer (lateral) part of the knee then a femoral osteotomy would usually be undertaken
Knee osteotomy has three main goals:
- Transfer the weight from the arthritic part of the knee to the healthier part
- To correct knee alignment
- To prolong the life span of the natural knee joint
Advantages of Osteotomy
By preserving the natural knee a successful osteotomy may delay the need for knee replacement for a number of years. This procedure is particularly of value in younger patients who place higher physical demands on their knees.
Disadvantages of Osteotomy
There are potential disadvantages to knee osteotomy. These include less predictable pain relief compared to partial or total knee replacement surgery and a longer recovery period.
Patients undergoing knee osteotomy are usually booked for a 2 day stay in hospital although this can be longer. The procedure is usually undertaken under general anaesthesia. The majority of osteotomies are done on the tibia where there is too much stress on the medial (inner) aspect of the knee. An approximately 8-10 cm incision is made on the inner aspect of the leg. Using alignment guides and x-ray screening the tibia is cut with a surgical saw. The tibia is then realigned and the the new position is fixed with a bone plate and screws. The operation typically last 1 – 2 hours.
Post Operative Period
A plaster cast is not normally required and the patient is mobilised partially weight bearing on the operated leg with the assistance of crutches. Crutches are normally required for a period of six weeks. During this period the patient undergoes physiotherapy to help their rehabilitation. You may be able to resume normal activities and return to work after 3 months although this may be longer.
As with any surgical procedure there are potential risks. Although the risks are low the most common complications includes:
- Thromboembolism (blood clots)
- Injuries to vessels and nerves
- Failure of the osteotomy to heal
- Stiffness of the knee joint
- Recurrence of pain which eventually requires knee replacement surgery
Osteotomy can relieve pain and delay the progression of osteoarthritis in the knee. It can allow a younger patient to lead a more active lifestyle for many years. Even though most patients will eventually require a total knee replacement, an osteotomy can be an effective way for a younger patient to buy time until a replacement is required.