What is Knee osteoarthritis?

Osteoarthritis of the knee is the most common joint disease in the world. It occurs when the layer of cartilage (a strong and flexible tissue that helps joints move smoothly and absorb shocks) on the end of the thigh bone or the top of the shin bone becomes damaged. This results in the bones rubbing against one another, causing pain and stiffness. Over time, this can cause even more damage as the abnormal movement wears away more cartilage and causes other abnormalities in the joint such as irregular bone growths. While the knee cartilage incurs some wear and tear from normal use, the ability of the body to repair it can be reduced by age, excessive stress or injury, and this is what leads to long-term degeneration of the joint.

What causes it?

When walking, much of the load is placed on the inside of the knee, due to the knees naturally ‘bowing’ away from one another. This causes a greater amount of wear and tear on the cartilage on the inside of the knee. When combined with other factors such as age, this cartilage can become damaged, resulting in the bowing becoming worse as the bones become closer together on the inside than the outside of the joint. This in turn leads to more stress and more damage, creating a cycle that ends in osteoarthritis. An attractive option in this case is to modify the joint to equally distribute the weight across the knee, rather than replacing the entire knee with an artificial joint; this surgical procedure is called High Tibial Osteotomy (HTO). It involves a cut into the top of the shin bone (tibia) to be slightly open to change the leg’s structure, resulting in a less bowed leg with the load carried by healthier tissue.

HTO a surgical alternative

As well as reducing pain and stiffness, this procedure has several other advantages. Perhaps the most attractive benefit of this procedure compared to a knee or partial knee replacement is that the natural joint being left in place allows for normal use of the knee after the surgery. This includes activities that would usually be unlikely after knee replacement, including sport!

HTO is a joint preserving surgical treatment; unlike knee replacement where the leg is irremediably detached to host the artificial implant, in a well performed HTO the bone will regenerate, and the reduced load often allows the damaged cartilage also to regenerate.

As knee replacement often leads to a sedentary lifestyle which causes other health conditions, HTO offers a great benefit for both young and old patients. Depending on age and level of activity, after 10 to 15 years of knee replacements, patients need a knee revision, resulting in a greater risk of infection or complications.

For younger and active patients, HTO is an attractive alternative to unicompartimental knee replacement (UKR) and also to total knee replacement (UKR).


TOKA applies 21st century technology to deliver HTO surgery precisely tailored to each patient.

The procedure requires a stabilising plate to support the tibial cut while it heals after the surgery. While traditional methods use a standard plate, TOKA offers titanium 3d printed which precisely fits the bone, avoiding the irritation to surrounding tissues and pain caused by a one size fit all solutions.

The plate is structurally optimised to patient conditions, resulting in a stronger structure and a faster recovery.

Helping yourself

Reducing the stress placed on the knee joint as much as possible for osteoarthritis patients both before and after a surgery is very important. The best way to do this is to lose weight and physical activity. Wearing soft soled shoes reduces the impact while walking – try to avoid high heels and hard soled shoes. Regular exercise will help as long as it is not too intense – swimming should be beneficial, but weightlifting or running on hard surfaces will not.

Read more about Knee exercising for Arthritis on ARTHRITIS-health website: