Knee Osteotomy: A Joint-Preservation Procedure for the Right Patient

Many patients who are told they have a “bow-legged” or “knock-kneed” knee ask whether an osteotomy might help them avoid a knee replacement. It's a great question — and in carefully selected patients, an osteotomy can be an excellent procedure. The key is understanding who benefits most, and who is better served by another path.

What is a knee osteotomy?

An osteotomy is a procedure in which a surgeon cuts and realigns the bone around the knee to change the mechanical alignment of the leg.

• In a bow-legged patient (varus alignment), excessive force is driven through the inside (medial) compartment of the knee.
• In a knock-kneed patient (valgus alignment), excessive force is driven through the outside (lateral)compartment.

By realigning the leg, an osteotomy shifts weight away from the overloaded compartment and redistributes force across the knee. Rather than replacing the joint, it attempts to preserve the patient's native knee. (Osteotomies are also done around the hip — for example, to treat hip dysplasia — but this article focuses on the knee.)

Who is the ideal candidate?

The patients who do best with a knee osteotomy are typically:

Many surgeons view osteotomy as a joint-preservation procedure designed to delay the development or progression of arthritis. Some candidates already have early cartilage damage or early single-compartment arthritis — and they can still be good candidates, as long as the disease stays localized and the rest of the knee is relatively healthy.

Why not just replace the knee?

This is one of the most common questions patients ask.

A knee replacement reliably corrects alignment and treats the damaged cartilage and arthritic joint surfaces. For patients with established arthritis affecting multiple compartments, replacement is generally the more predictable solution.

The challenge with an osteotomy is that it does not replace damaged cartilage — it only changes how forces are distributed across the joint. For that reason, patients with advanced arthritis throughout the knee are typically poor candidates.

Recovery after osteotomy

Recovery from an osteotomy can be significant, because the bone has to heal. Patients should understand that:

In some cases recovery is more prolonged than patients expect. While many ultimately return to high levels of activity, the rehabilitation is often more demanding than many other orthopedic procedures — and notably more involved early on than a modern knee replacement recovery, which allows earlier weight-bearing.

Does an osteotomy prevent arthritis?

Not necessarily.

The goal of an osteotomy is to reduce abnormal loading and slow the progression of cartilage damage. In the right patient, it may delay the need for a knee replacement by many years. But it does not guarantee that arthritis won't eventually develop — and many patients who undergo an osteotomy ultimately require a knee replacement later in life. That's not a failure of the operation; for a younger patient, delaying a replacement to a later age is often exactly the point.

Osteotomy vs. knee replacement

The fundamental difference is the treatment goal:

From Dr. Harb

In my practice, an osteotomy is most appropriate as a joint-preservation procedure for carefully selected younger patients with significant malalignment and relatively preserved cartilage.

Once meaningful arthritis has developed — particularly when multiple compartments are involved — I generally believe it's more effective to correct both the arthritis and the alignment with a knee replacement, rather than perform a major realignment that leaves damaged joint surfaces behind. Every patient is different, and treatment should be individualized based on age, activity level, alignment, cartilage health, symptoms, and long-term goals.