High Tibial Osteotomy

When to consider it

This operation suits a particular kind of patient: fairly young and active, with arthritis on one side of the knee, and a leg that has bowed inwards so that all the body's weight goes through the worn side. Replacing that knee would work, but a replacement at forty will need revising, possibly more than once. Realigning the leg buys years on your own joint.

It suits you best when:

• You are roughly under fifty-five and want to stay active, including at work
• Wear is on the inner side of the knee, with the outer side still in good condition
• The leg is visibly bow-legged, and the alignment is the reason that side is wearing
• The knee still bends well and is stable, with intact ligaments
• You would rather delay a replacement than have one now

It is the wrong operation for arthritis across the whole knee, for inflammatory arthritis, or for a knee that is already stiff. In an older or less active patient a replacement usually makes more sense. If the wear is confined to one compartment, that can be a partial knee replacement instead of a full one. You will be told directly if that is the better option for you.

What the operation involves

Planning matters more here than in most operations, because the aim is a precise correction, measured in degrees. Full-length standing X-rays measure the current alignment and show exactly how far the bone needs to move.

In theatre the tibia is cut just below the knee and opened, or occasionally closed, to the planned angle, then held with a plate and screws while it heals. Bone graft or a substitute is sometimes used to fill the gap. The joint itself is not opened for the correction, though an arthroscopy is sometimes done at the same sitting to deal with a torn meniscus or loose cartilage.

Recovery, week by week

Recovery takes longer than after a knee replacement, because the cut bone has to knit together before the leg can take your full weight. These are typical ranges.

• Week 0 to 2. Hospital stay of a few days. Walking with crutches, putting only limited weight through the leg. Knee bending exercises start early.
• Week 2 to 6. Still on crutches with protected weight-bearing. X-rays check that the cut is healing in the planned position.
• Week 6 to 12. Weight through the leg is increased as the X-rays allow, and most people are off crutches somewhere in this window. Proper strengthening work begins.
• 3 to 6 months. The bone is normally united. Walking distance, stairs and general activity build back up.
• 6 to 12 months. Return to sport and heavier physical work, once strength and healing allow it.

Follow the instructions on how much weight to put through the leg exactly. Loading a cut bone too early is the main way this operation goes wrong.

What it buys you

A well-aligned osteotomy commonly gives a decade or more of good function on your own knee, and often longer if you keep your weight down. It does not cure the arthritis, and it does not promise the knee will never need replacing. It pushes that decision back to an age when a replacement makes more sense.

A knee replacement is still possible afterwards if you eventually need one. The plate is usually removed first if it is still in place. The replacement is a little more involved than a straightforward one, but it is done routinely.

Risks

The risks specific to this operation are the bone failing to unite or uniting slowly, a correction that ends up short of or beyond what was planned, and irritation from the plate, which is sometimes removed once healing is complete. Infection, clots in the leg or lung, stiffness and injury to nerves or vessels apply here as they do to any knee surgery.

Smoking matters more for this operation than for most, because it directly impairs bone healing. If you smoke, stopping before surgery is part of the treatment.

Common questions

Not sure this is your problem?

These pages start from the symptom. They cover what else can cause it and what is usually tried first.