In recent years, the incidence of knee osteoarthritis (OA) in individuals below the age of 60 has been increasing. Specifically, OA can be induced or aggravated by knee malalignment. The most common form of knee malalignment is “genu varum” or “bow-leggedness”. The other form is known as “genu valgum” or “knock-knees”. Malalignment causes overloading of one compartment iof the knee. For example, in genu varum the medial or “inner” compartment of the knee gets overloaded and with or without additional injury to the cartilage or meniscus of the knee, medial compartment OA can develop. Similarly, in genu valgum, lateral or “outer” compartment OA can develop.
A joint preserving osteotomy does not replace the joint. Instead, either or both of the thigh (femur) and shin (tibia) bones are cut and the limb is realigned so that the leg is straightened. This allows the body weight to be distributed evenly through the knee joint. Therefore, the pressure on the already damaged cartilage in the knee is relieved and this allows some healing capacity in the long-term.
Figure 2: An example of a joint preserving osteotomy performed over the right knee of a patient with a varus knee OA using a minimally invasive approach with small implants. Note how the weight bearing line has been moved away from the inner compartment to allow for the damaged cartilage to heal.
Advantages of Joint Preserving Osteotomy
While joint replacement surgery may be an excellent option for older patients with end-stage arthritis, young active patients do not do as well. In younger patients with active lifestyles, joint preserving osteotomy can delay or obviate the need for joint replacement surgery. The key advantages for joint preserving osteotomy include:
