Osteotomy Surgery / Limb Realignment

Overview

Knee osteoarthritis can develop due to underlying problems with leg alignment. There are 3 different types of leg alignment:

• Varus (bow legged)
• Neutral (straight)
• Valgus (knock kneed)

In varus and valgus knees, the body weight and forces are acting excessively in one compartment or the other. In varus knees, the forces pass through the medial compartment and in valgus knees, the forces pass through the lateral compartment.

This leads to excessive wear and damage to cartilage in one part of the knee joint only, meaning that the rest of the joint remains relatively spared.

Osteotomy surgery aims to realign the leg and offload the forces from the arthritic part of the joint to the healthy part of the knee joint.

This means that knee replacement surgery can be avoided for a significant period of time and the native knee joint preserved.

This is a particularly beneficial solution for younger patients with knee OA and once the alignment is corrected, the progression of osteoarthritis can be delayed in most cases.

The Procedure - What to Expect

There are two types of osteotomy surgery - high tibial osteotomy and distal femoral osteotomy.

High Tibial Osteotomy

This is the most commonly performed osteotomy operation, usually for varus knees with medial compartment OA.

Once the angles and the correction have been calculated, an incision is made over the top end of the shin bone (tibia) and the bone exposed. An incision is then made in the bone (osteotomy) from the medial side of the tibia towards the lateral cortex of the bone. Care is taken to preserve the lateral cortex and the osteotomy site is gently opened which gradually corrects the axis of the bone to the desired point.

This is then carefully held in position and a strong metal plate applied to hold the bone in place.

This results in the body weight forces passing through the healthy part of the knee joint and therefore eliminating the pain.

Recovery from a High Tibial Osteotomy

Recovery is the real test of this operation. Because it involves cutting and realigning the bone, some postoperative pain is to be expected — but it's generally well controlled with simple painkillers for the first two to six weeks, after which pain and swelling steadily ease. Patients can weight-bear from the outset with the support of crutches. In a small number of cases, a minor crack appears in the outer part of the bone, which may call for a brace alongside crutches, though this is the exception rather than the rule.

Stitches or skin clips are typically removed at around two weeks, followed by a first review at six weeks, when x-rays check progress. Further x-rays at three and six months confirm the bone is healing well. It's usually from around three to six months that patients really start to feel the difference, as pressure shifts away from the arthritic side of the knee and onto the healthier side — often bringing dramatic, and sometimes complete, relief from osteoarthritis symptoms.

Once the bone has fully healed, typically by around 12 months, the metal plate used to hold the correction in place is removed in a simple day-case procedure — the final step in the journey back to a stronger, better-aligned knee.

Distal Femoral Osteotomy

This is less commonly performed and is usually for valgus knees with OA in the lateral compartment.

After careful planning, an incision is made on either the inside of the thigh or the outside of the thigh, just above the knee. The distal end of the femur is exposed, and an incision made in the bone (osteotomy). The desired correction is achieved, and a strong metal plate applied to hold the correction in place.

This results in the body weight forces passing through the healthy part of the knee joint and therefore eliminating the pain.

Recovery from a Distal Femoral Osteotomy

A distal femoral osteotomy works a little differently to a high tibial osteotomy. Rather than opening a gap in the bone that then needs to fill in and form new bone for stability, this procedure involves removing a small wedge and closing the gap, bringing the bone edges together and securing them with a plate. With the bone surfaces directly opposed, healing tends to be more straightforward — generally speaking, recovery is quicker and more comfortable than after a high tibial osteotomy, with patients typically reporting faster pain relief.

That said, the long-term results between the two procedures are comparable, and the overall recovery pathway follows a similar course. As with a high tibial osteotomy, the metal plate is generally removed around a year after surgery, once the bone has fully healed.

Outcomes

• 20+ years of experience
• 150+ osteotomies performed
• <1% complication rate