What is a knee osteotomy?
A knee osteotomy commonly refers to a tibial osteotomy. This is a deliberate controlled surgical break in the tibia (shin bone), with the purpose of re-aligning the limb.
Knee osteotomy – why do we do this?
Young patients with knee arthritis represent a difficult management problem. Knee replacements are a great operation, but are best suited to the middle to older age groups with less demand. Over time, knee replacements ‘wear out’, especially in young active people. In the older patient, this is usually not seen.
Young patients who have isolated knee arthritis and mal-alignment of their leg may be better suited to a tibial osteotomy. The primary goal of the osteotomy is to correct the mal-alignment and decrease the forces going through the arthritic part of the knee joint.
Once the osteotomy has healed, patients can essentially return to full function including manual labor and an active lifestyle.
Knee osteotomy – what types are available?
Osteotomies can be performed to either realign the limb into more ‘valgus’ or more ‘varus’ depending on the location of the arthritis.
The most common scenario involves a patient that has ‘varus’ alignment to the limb (with the lower leg angled inwards) with arthritis affecting the medial (inner) compartment of the knee.
In this situation, the aim of the tibial osteotomy is to re-direct the weight bearing force through the non-affected lateral (outer) compartment. This is typically done through one of two methods
Medial (inner) opening wedge tibial osteotomy
This osteotomy involves creating a single ‘osteotomy’ or break on the inside of the tibia (shin bone) and the ‘osteotomy’ is opened to realign the limb
Lateral (outer) closing wedge tibial osteotomy
This osteotomy involves creating two ‘osteotomies’ on the outside of the tibia and a wedge of bone is removed to ‘close down’ the gap, realigning the limb
Medial opening wedge tibial osteotomy
Dr. Smith performs a knee osteotomy using this technique. Prior to the procedure, a detailed assessment will be performed to ensure that you are suitable for this option. Younger patients with isolated arthritis are the ideal candidates.
The potential advantages of this technique compared to the lateral closing wedge osteotomy include:
- Only one osteotomy is required – allows greater control of the ‘correction’
- You dont need to disrupt the fibula head
- You restore bone stock, rather than remove bone
Dr. Mike Smith uses the latest patient specific instrumentation (PSI) to achieve the desired surgical correction. A combination of standing xrays and a specialised CT are used to calculate the degree of correction required.
Using your individual imaging, an osteotomy (‘cutting’) guide is specifically manufactured for your procedure!
You will be admitted to hospital on the day of the operation, and met by the anaesthetist. Anaesthetic options are discussed including a detailed pain relief plan.
The operation involves making an incision on the inside of the top part of the shin bone (tibia). Your custom made ‘osteotomy’ guide is attached to your tibia and the positioning is checked with an Xray. Once satisfied that this is correctly positioned, a saw is used to create the ‘osteotomy’ under careful xray guidance and protection of the surrounding tissues.
The ‘osteotomy’ is then gradually opened until the desired ‘correction’ has been obtained. This is again confirmed under xray control.
A plate and screw construct is then positioned, to hold the leg in its new position. Depending on the size of the gap (‘opening’), bone graft may be used to fill in this void. This bone can either be taken from your pelvis (iliac crest) or donor bone can be used. The wounds are closed and a bandage and brace are applied.
Knee osteotomy – Recovery
You will stay in hospital overnight and your degree of comfort will be monitored. The physiotherapy and nursing staff will help you gain confidence on a set of crutches.
You will need to use the crutches for for up to 12 weeks. After the initial 6 weeks, you will be able to remove your knee brace and start to put some weight through your leg.
You will be seen by Dr. Smith regularly during this time period, with xrays taken to assess for healing of the tibial osteotomy.
Gradual return to function occurs once the crutches are removed. Your occupation will determine how soon you can return to work. In an admin role with a hight amount of sitting down, you may be able to return to work after 3-4 weeks. If you work in manual labour, this may take up to 4-5 months.
Once successful healing has occurred, you can return to an active lifestyle.