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Knee realignment surgery (osteotomy)

We explore what knee realignment surgery involves.

Your knee joint is a hinge joint divided into two parts. These are the inside of the knee joint (medial compartment) and the outside of the knee joint (lateral compartment). 

Realigning the knee can prevent pain and prevent an onset of early degenerative changes in your joint (age-related changes to your body).

If you have a fully functioning knee joint structure, there should be good alignment and balance between the aforementioned two parts of your knee when you are standing upright.

If your knee leans towards the outside or inside too excessively, it can put abnormal and excessive weight on the medial or lateral parts of your knee. This might need to be surgically corrected with knee realignment surgery.

Knee realignment surgery, also known as a knee osteotomy, is an operation whereby your bone is cut to shorten, lengthen, or change its alignment. The procedure is carried out under general anaesthetic and is commonly used to treat people who are bow-legged or have knock knees. 

Knock knees

Knock knees, which is medically referred to as genu valgum, is a condition where your knees angle in and touch when the legs are straightened. People with severe valgus deformities are typically unable to touch their feet together while straightening their legs at the same time.

A mild case of knock knees (genu valgum) is relatively common in children up to the age of two years and is often corrected naturally as your child grows and develops. However, if the condition is the result of obesity or rickets (a condition that affects bone development in children), it could continue or worsen with age.

Idiopathic is a term used to describe knock knees that has no known cause.


Bow-leggedness, medically known as genu varum or Blount's disease, is a deformity that creates an outward bowing of your legs and causes your legs to resemble a bow. In most cases, your femur (thigh bone) and tibia (bone in your lower leg) usually curve outwards. Sometimes your tibia can also bend inwards.

Bow-leggedness is also called bandy-leg, bowleg, bow-leg, and tibia vara.

Knee realignment surgery involves several stages and takes place under a general anaesthetic. Using X-rays taken before the operation, your Consultant will assess the degree of realignment that needs to be undertaken.

Once these measures have been taken, your surgeon will use specialised instruments to carry out an opening wedge cut near the top of your tibia (your lower leg bone).

Your surgeon will then realign your knee's angle by levering the ends of your tibia together at the wedge of bone. The fractured ends are secured with a strong plate and screws. If necessary, a bone graft will be added to secure the fractured tibia further. The most common form of knee realignment surgery described here is termed a high tibial osteotomy.

The technique used to realign a knee depends on the correction that is required. An opening wedge osteotomy happens when your bone is cut using specialist equipment and opened with chisels to create a wedge-shaped opening.

A closing wedge osteotomy happens when your bone is cut twice and a small wedge of bone is removed.

Mobility and dressing aids such as specialised wheelchairs and dressing sticks can support your recovery following knee realignment surgery.

It is normal for osteotomy patients who have undergone knee realignment surgery to not bear any weight (non-weightbearing) on their operated leg for up to six weeks. After this period, a specialist team will take further X-rays to ensure that your fractured ends have healed sufficiently to allow you to start bearing your weight again.  

Following this initial period, our physiotherapists will supervise and guide you through a comprehensive rehabilitation package until you are able to walk normally and return to your daily activities and any high-impact sports (if applicable). 

Initially, rehabilitation after knee realignment surgery will often comprise of simple range of motion and flexibility exercises to ensure full mobility to yoyr knee is restored. Non-weight bearing strengthening exercises will also be advised to prepare the knee for more aggressive exercises later down the line. 

Higher level rehabilitation will involve weight-bearing exercises to restore optimum function and fitness to the operated leg. These types of exercises may include: 

  • Wall squats;
  • Lunges;
  • Step ups, and
  • Using a leg press machine.

Like knee replacement surgery, there are similar risks associated with having a knee realignment surgery such as the risk of developing an infection or blood clot.

If successful, a knee realignment surgery can help treat bowed legs or severe and persistent knock knees. Undergoing knee realignment surgery or an osteotomy due to knock knees or bowed legs can also redistribute your weight across your knee joint, relieve pressure off any damaged cartiliage and support your knee joint's life span.

The cost of having knee realignment surgery (knee osteotomy) varies between locations. It includes all your hospital visits, such as initial consultation, the surgery and recovery afterwards when you are an inpatient. Our high-quality care is reflected within our costs. 

If you would like to learn more, please contact a member of our team by calling us directly or booking your appointment online. At your consultation, your Consultant will discuss your symptoms and recommend treatment with you. 

Specialists Offering Knee realignment surgery (osteotomy)

Mr Benjamin Bloch

Consultant Orthopaedic Surgeon

BSc MBBS FRCS (Tr & Orth)

BMI The Park Hospital

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Mr Vikram Desai

Consultant Orthopaedic Surgeon


BMI The Park Hospital

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Mr Joby John

Consultant Orthopaedic Surgeon

MBBS, MS(Orth), FRCS(Orth), PhD

BMI The Park Hospital

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Mr Nitin Badhe

Consultant Orthopaedic Surgeon

FRCS(Orth), Mch Orth, MS Orth, DNB Orth, FCPS Orth, D’Orth, MRCS Surg

BMI The Park Hospital

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Mr Khosrow Sehat

Consultant Orthopaedic Surgeon

MBChB; MRCS; FRCS (Trauma and Orthopaedics)

BMI The Park Hospital

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