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 passthrough 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 fora 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 avoided in some cases.
A physical examination and thorough history are required as well as routine knee x-rays.
A long leg alignment x-ray is also carried out. This allows us to calculate the various angles, work out where the deformity exists, and plan the corrective surgery.
An MRI scan may also be necessary to check the health of the rest of the knee to confirm eligibility for the surgery and to exclude any other major pathology.
There are two types of osteotomy surgery - high tibial osteotomy and distal femoral osteotomy. Learn more about each of these below.