Key points

• Knee osteotomy is a joint-preserving procedure that realigns the leg to improve how forces pass through the knee
• It works by shifting weight away from the damaged part of the joint to a healthier area
• High tibial osteotomy (HTO) is used for bow-legged (varus) alignment affecting the inner knee
• Distal femoral osteotomy (DFO) is used for knock-kneed (valgus) alignment affecting the outer knee
• Anterior closing wedge osteotomy can reduce tibial slope in revision ACL surgery and protect the graft
• It is particularly suitable for younger, active patients with early arthritis or alignment issues
• Often performed alongside ligament reconstruction or cartilage procedures
• Recovery takes time, but can delay or avoid the need for knee replacement
• Best outcomes are achieved with accurate correction and structured rehabilitation

What is a knee osteotomy?

A knee osteotomy is a surgical procedure used to realign the bones around the knee to improve joint function and reduce pain.

Rather than replacing the joint, an osteotomy rebalances the load across the knee, shifting weight away from a damaged or overloaded area.

It is most commonly used in:

• Younger or active patients
• Patients with early arthritis affecting one side of the knee
• Patients with alignment issues contributing to ligament problems

Why is an osteotomy needed?

In a normal knee, weight is distributed evenly across the joint. However, if the leg alignment is altered, excessive load can be placed on one side.

Common situations include:

• Bow-legged alignment (varus): Increased load on the inner (medial) side of the knee
• Knock-kneed alignment (valgus): Increased load on the outer (lateral) side of the knee
• Ligament instability: Malalignment can place excessive strain on reconstructed ligaments
• Revision ligament surgery: Alignment and slope may need correction to protect grafts

How does an osteotomy work?

An osteotomy works by changing how forces pass through the knee joint.

Before correction (malalignment)

• In varus alignment, most of the body weight passes through the inner (medial) compartment
• In valgus alignment, load is concentrated on the outer (lateral) compartment
• This uneven loading leads to pain, cartilage wear, and progression of arthritis

After osteotomy (realignment)

• The weight-bearing axis is shifted toward the healthier side of the knee
• Forces are more evenly distributed
• Pain is reduced and joint function improves
• This can slow down or delay further joint damage

Types of knee osteotomy

The type of osteotomy depends on the underlying problem and where the deformity arises.

High tibial osteotomy (HTO)

A high tibial osteotomy is performed on the upper part of the tibia (shin bone).

• Commonly used for varus (bow-legged) alignment
• Shifts weight from the worn inner part of the knee to the healthier outer side
• Often used in patients with medial compartment arthritis or overload

Distal femoral osteotomy (DFO)

A distal femoral osteotomy is performed on the lower part of the femur (thigh bone).

• Used for valgus (knock-kneed) alignment
• Reduces load on the outer (lateral) compartment of the knee
• Particularly useful in younger, active patients with lateral compartment symptoms

Anterior closing wedge osteotomy (for ACL revision)

In some patients undergoing revision ACL reconstruction, the posterior tibial slope (PTS) is increased.

An increased slope can:

• Place excessive strain on the ACL graft
• Contribute to graft failure

An anterior closing wedge osteotomy reduces the tibial slope by:

• Removing a wedge of bone from the front of the tibia
• Decreasing the posterior slope
• Reducing forces on the ACL graft

This is a specialised procedure typically performed in selected revision cases.

Surgical technique

Osteotomy involves:

• Making a controlled cut in the bone
• Adjusting the alignment to the desired position
• Fixing the bone with a plate and screws

The procedure may be:

• An opening wedge (creating a gap)
• A closing wedge (removing a section of bone)

The choice depends on the deformity and surgical plan.

Do I need an osteotomy or a knee replacement?

An osteotomy is often considered when:

• You are younger and active
• Arthritis is limited to one part of the knee
• You wish to preserve your natural joint
• There is correctable malalignment

A knee replacement may be more appropriate if:

• Arthritis is advanced and widespread
• Symptoms are severe and persistent

This decision is made on an individual basis following detailed assessment.

Recovery and rehabilitation

Recovery from an osteotomy requires time for the bone to heal.

Typical rehabilitation includes:

• Use of crutches initially
• Gradual progression of weight bearing
• Physiotherapy to restore movement and strength

Return to activities:

• Daily activities: 6–12 weeks
• Low impact activity: 3–6 months
• Higher level activity: 6–12 months

Recovery may vary depending on the type of osteotomy performed.

Outcomes

With appropriate patient selection:

• Osteotomy can significantly reduce pain
• Improve function and activity levels
• Delay or avoid the need for knee replacement

By correcting alignment and redistributing load, osteotomy helps to:

• Protect remaining cartilage
• Improve joint mechanics
• Support ligament reconstructions where required

Why choose specialist care?

Osteotomy is a precise, technically demanding procedure that requires careful planning.

Specialist care ensures:

• Detailed assessment of alignment and biomechanics
• Accurate correction tailored to the individual
• Integration with ligament reconstruction when required
• Structured rehabilitation

Summary

• A knee osteotomy realigns the bones to improve load distribution
• It works by shifting forces away from damaged areas of the knee
• High tibial osteotomy (HTO) is used for varus alignment
• Distal femoral osteotomy (DFO) is used for valgus alignment
• Anterior closing wedge osteotomy can reduce tibial slope in revision ACL surgery
• It is a joint-preserving option, particularly in younger, active patients
• Good outcomes are achievable with appropriate selection and specialist care