Total knee joint replacement is ultimately required in late-stage knee osteoarthritis. But arthritic inflammation and degeneration start long before that. What is pre-osteoarthritis? What is early osteoarthritis? How to recognize its symptoms? What can trigger the start of arthritis in the knee? What are treatment options for early osteoarthritis of the knee? You have done extensive research in that area. In general, the initiation of pre-osteoarthritis or early osteoarthritis is mostly trauma or overloading, overuse of knee joint. So when we talk about osteoarthritis, then we have to look if it’s primary osteoarthritis. It is more genetically-related or metabolism-related. Or is it so-called secondary osteoarthritis, which is more trauma-related? When we go back to early osteoarthritis, an athlete had the pathologic turn of the knee and got ACL rupture. In that situation, we know from some studies, that’s a metabolic-related situation. After the knee trauma, the cartilage is changed for a while, like six months. So the metabolic activity is damaged. But we would not see that on an MRI. We would not see that in an X-ray. For that reason, we have an area of changes in the metabolism of cartilage situation, which is very early and could not objectively be seen in MRI or X-ray technique. We have a pre-osteoarthritis or early osteoarthritis. Mostly we see that we could objectively evaluate the situation. We can do a joint puncture and analyze the molecules in the knee. We see that there are more degradation-related molecules and active inflammation markers. But in the X-rays, we would not see that pathology. That makes it so difficult to diagnose early osteoarthritis. The normal timeframe to go forward is after initiation and trauma like ACL (Anterior Cruciate Ligament) rupture. We would see in a time window of two to three years some deterioration of the joint. In a very early stage, we would not see that. We might not address early joint damage with good therapy. It means stabilization of a joint, removal of any mechanical problems like instability. Then osteoarthritic changes go forward. This is like a driving force of knee osteoarthritis. If osteoarthritis is starting on the surface of the cartilage, so we know that the cartilage fibrillation (shredded appearance) on the surface is not a huge osteoarthritic damage situation. But it is the starting point to destroy the whole knee joint over the years. So we have to carefully identify the osteoarthritis situation very early. We have to address the mechanical reasons for all that damage and cure it as well as possible. Then we can change some factors which support the conservation of the cartilage damage. If fibrillation (shredded appearance) on the joint surface goes forward further, then we see some inflammation in the joints. Then the hyaluronic acid injection could help to protect a little bit the surface of the cartilage from more damage, for example. So there are some tools to treat early osteoarthritis. We have PRP injections. We can give some nutritional support to the cartilage. These are mostly antioxidative treatments, which are the factors that reduce inflammation in the tissues. Inflammation damages the cartilage tissue all the time. The main point of knee osteoarthritis treatment is to identify a situation very early. You must put the whole treatment concept individually for each patient. You must look inside the knee joint as much as possible. You must cure a joint mechanically as good as possible. You have to add molecular factors to give the patient a good joint function in the long run.