1, the prevention and treatment of patellofemoral joint disease Clinically, there are quite a few patients who visit the clinic with knee pain, and a significant number of them are found to have only mild signs of patellofemoral joint surface degeneration after a radiograph, in fact, this type of disease is patellofemoral joint disease. The complaints of this type of disease are that the pain occurs when going up and down stairs, half squatting or preparing to stand from a seat, when the knee is in semi-flexion and the patella and femur are under maximum contact stress. The patellofemoral joint consists of the patella and femoral trochanter articular surfaces, whose stabilizing structures include the longitudinal quadriceps tendon, patellar ligament, and lateral internal and external femoral obliques, medial and lateral support bands, and the iliotibial bundle; normal soft tissue tone and bone and cartilage structures adjacent to the patellofemoral joint are essential to maintain the mechanical effectiveness of the knee extension device. The patellofemoral articular surface contact begins at 20 degrees of knee flexion, and as the knee flexion angle increases, the patellofemoral articular surface contact area also increases. The pressure between the patellofemoral joint is highest at 60 degrees-90 degrees of knee flexion, and at knee flexion beyond 90 degrees, the quadriceps tendon contacts the femur, which reduces the patellofemoral joint pressure. Most scholars believe that the pain produced by the patellofemoral joint is related to overloading of the patellar surface and excessive tension of the lateral ligaments. The clinical symptoms of patellofemoral disorders have many similarities with meniscal and cruciate ligament injuries. However, except for the traumatic category, patellofemoral joint disorders do not have an obvious history of trauma, and the clinical symptoms appear more slowly, often after the onset of one side, similar lesions can be found on the other side, or both sides at the same time. 2, patellofemoral joint disease treatment Many scholars recommend conservative treatment first, including rest, appropriate braking, quadriceps training, local application of protective brace, taking non-steroidal anti-inflammatory and analgesic drugs. At the same time, taking some drugs to nourish the articular cartilage, such as glucosamine and chondroitin sulfate, can also help to some extent. However, since articular cartilage is hyaline cartilage and cannot be regenerated after wear and tear, these articular cartilage nutrition drugs can only delay the degeneration of other articular cartilage, but cannot promote the growth of new hyaline cartilage. For patients, it is more important to take care of their lifestyle habits, such as avoiding prolonged sitting, climbing stairs less often, holding the railing when squatting or going up and down stairs to relieve pressure on the knee joint, etc. These actions seem very small, but because they are repeated very frequently, it is very important to do them consistently to prevent the aggravation of patellofemoral joint disease. The red line on the joint surface in the figure below is the wear and tear on the joint surface.