High tibial osteotomy

Overview

Front view of the knee showing the femur, tibia, patella, cruciate and collateral ligaments, and the medial and lateral menisci. — **Knee anatomy.** The knee is the meeting point of the thigh bone (femur), shin bone (tibia), and kneecap (patella). Four ligaments hold it together — the ACL and PCL inside the joint and the MCL and LCL on the sides — and two C-shaped menisci cushion the joint surfaces.

When a younger, active patient has arthritis limited to one side of the knee — usually medial — and their leg bows into varus, the damaged compartment is overloaded with every step. Replacing the knee would work, but a joint replacement has a finite lifespan in a demanding patient. Realigning the tibia shifts load off the worn compartment and preserves the native joint.

How the Procedure Works

The correction angle is calculated preoperatively from standing long-leg X-rays — we aim to shift the mechanical axis from the worn compartment to a point just lateral to the center of the joint, typically to 62–66% across the tibial plateau. Under-correction leaves the patient with residual pain; over-correction unloads the repaired compartment but overloads the opposite one. We use a medial opening-wedge technique in most cases: a transverse cut is made in the proximal tibia, the wedge is opened to the planned angle under fluoroscopy, filled with bone graft or substitute, and held with a locking plate. The lateral cortex is left partially intact as a hinge — maintaining that hinge prevents the osteotomy from collapsing before it heals. Patients are protected with partial weight-bearing for six to eight weeks while the bone consolidates.

When to Consider High Tibial Osteotomy

High tibial osteotomy is generally offered when symptoms, imaging, and a trial of non-operative care together point to surgery as the next step. The typical picture includes:

Unicompartmental arthritis with malalignment
Isolated medial or lateral compartment wear, matched to a varus or valgus leg axis on standing X-rays.
Active patient preserving a native knee
Patients who want to keep running, hiking, or doing physical work that would stress a knee replacement.
Preserved motion and ligaments
A knee with good range of motion and intact cruciate and collateral ligaments.