Osteotomy refers to Nigel making a cut in either the femoral or tibial bone and changing the direction of that bone either by opening up a wedge or removing a wedge.

There are two different types of osteotomy that can be done:

  • High tibial osteotomy
  • Distal femoral osteotomy

The high tibial osteotomy (HTO) is done much more commonly but in a small number of cases a femoral osteotomy may need to be done. Nigel performs the surgery using computer navigation. This x-ray image shows a high tibial osteotomy.

High Tibial Osteotomy (HTO)

High tibial osteotomy (HTO) is an operation done for osteoarthritis of one part of the knee joint only.

  • It is a good option to use in young patients less than 55 years
  • It is an intermediate step. It will not stop the progression of arthritis but it will slow it down
  • There is a 60-75% success rate at 10 years with this operation

The knee joint is effectively three joints in one:

  • There is a medial (inside) compartment
  • There is a lateral (outside) compartment
  • There is a patello-femoral (knee-cap) compartment

This procedure involves surgically breaking the proximal tibia (top part of the leg bone) and creating an angle in the bone. The reason why this is done is to take the load off of that compartment (most often medial) and to redistribute it to the lateral (outside) compartment.

It is not a suitable operation for everyone and there are a number of factors that will determine whether you are a suitable candidate and Nigel will discuss with you whether HTO is suitable for you.

These factors are:

  • Age
  • Weight
  • Smoking status
  • Range of movement
  • Examination features
  • Arthroscopy findings

Realignment for Knee Cap Problems

For patients who have problems with their patella (knee cap) dislocating, then sometimes surgery may need to be performed that helps to reduce dislocation from occurring. This may require surgically breaking a part of the tibia and re-aligning it so that the knee-cap can move more anatomically.

Prior to surgery

Osteotomy often requires 1-4 nights in hospital and extra tests may be required.

Nigel will ask you if you:

  • have any medical conditions
  • are on any medications
  • have any allergies 
which may mean you may need to have further tests or be referred to a physician for further assessment
  • You may not meet the Anaesthetist until the day of surgery
  • If you take any blood thinning medication, please tell Nigel as in certain cases 
you may need to stop this medication for a period of time prior to surgery
  • You will be given an information pack for HTO on the day you are booked for surgery 

Day of Surgery

  • Do not have anything to eat or drink within 6 hours of your operation.
  • If you do there is a good chance your operation will not be performed on that day and will have to be rescheduled.
  • The nursing staff will make sure that all x-rays, blood tests, and medications are present.
  • The area to being operated on will be clipped, washed and prepped.
  • You will be asked many times what operation you are having done. This is so that no mistake is made.
  • Nigel will meet with you, will mark the operation site, make sure the consent form is signed, ask you if you have any questions, will check to see that next of kin details are correct so he can call after the operation is performed.
  • It is completely normal to be nervous, and anxious, but if you feel that things are getting on top of you, please inform a staff member, because we will be able to give you a medication to help calm you.

In the operating theatre 

  • You will have an intra-venous (IV) line placed into a vein in your hand or arm.
  • You will be given oxygen to breathe and the Anaesthetist will then drift you off to sleep.
  • A torniquet will be placed around your thigh to restrict blood flow to the knee, to enable the operation to be performed.
  • Antibiotics will be given.
  • Initially you will have an arthroscopy of your knee to assess the level of arthritis and have any abnormality in the knee joint attended to.
  • You will have 2 small incisions for the arthroscopy of the knee and have one larger cut on the inside part of the leg 
where the osteotomy will be cut, and a plate put on the side of the bone.

Immediately after surgery

  • You will wake up in recovery.
  • Local anaesthetic will be placed into the knee joint and also into the incisions (cuts) at the front of your knee.
  • The incisions (cuts) around the front of your knee will be steri-stripped together.
  • Your knee will have two waterproof dressings placed over the steri-strips.
  • Your knee will then be bandaged and a brace will be around on your knee.



About 1%. If you do get an infection or think you may have an infection please seek medical advice as soon as possible. Most of the time you will just need to take antibiotics. On a small number of occasions you may need to be admitted to hospital for antibiotics and even rarer still you may need to have an operation to wash the infection out.


Can take up to 8 weeks to settle down.


Can take up to 8 weeks to settle down Pain. Initially it will be sore, as Nigel has surgically broken your tibia. The pain does settle down but takes about 10-14 days. It will be niggly for up to 6 weeks. It may also be more painful as you start to weight-bear, or increase your activity level.


Seventy percent of people will report numbness on the outside part of their knee or at the top of their leg after the operation. This generally will settle down but could take a number of months.

Blood clots

DVT can occur and has been reported in up to 20% of patients undergoing HTO. If this occurs you will be given an injection in your tummy to thin the blood

Before theatre you will be assessed as to your risk of DVT. If you are high risk you will be placed on a blood-thinning injection whilst in hospital.


This is where the osteotomy does not heal.

If you are a smoker, have diabetes, do not allow enough time for it to heal, amongst other factors may result in the osteotomy not healing.

Patella baja

This is a condition where the osteotomy causes the patella (knee-cap) to sit lower than what it normally would.

Complete fracture

Sometimes a fracture can occur on the outside of the tibia, which may mean that a further cut has to be made and a plate placed on the outside of the tibia, or that your weight-bearing may be delayed until the fracture has healed.


  • The knee joint will become stiff, as you will not be putting weight on your leg for a period of time and you will not be moving your knee normally.
  • Nigel will arrange for you to see a physiotherapist before and after your operation.

Progression of arthritis

  • Performing the HTO will alleviate your symptoms. It will not alter the arthritis and may slow it down. It will not stop you from getting arthritis in the other compartments of the knee.
  • Remember this operation is an intermediate step towards maybe needing a total knee joint replacement.

Success rate

  • High tibial osteotomy has a good success rate.
  • 60-75% of people undergoing the procedure will still have a functioning knee with occasional pain at 10 years.
  • Unfortunately some people will not get relief from the osteotomy and if this is the case other causes for the knee pain may need to be identified.
  • Nigel may well offer you total knee joint replacement.

View Case Study - Osteotomy