Lateral patellar hyperextension syndrome is an under-recognized condition in the domestic medical community and is an important cause of knee pain in middle-aged and elderly patients. X-rays can clearly show narrowing of the lateral patellofemoral joint space and hyperplasia. If the disease gradually worsens, it can develop into osteoarthritis of the whole joint, causing irreversible joint damage and eventually necessitating joint replacement. Therefore, it is recommended that middle-aged and elderly people with such similar symptoms come to see us as early as possible so that we can try to save your knee joint. This is because our technology allows you to undergo only a minimally invasive arthroscopic procedure, which focuses on the release of the lateral support band and the cleaning of the joint lesion. The recovery is fast and the results are long-lasting. Of course, active patient cooperation and practice of muscle strength are also required, which should result in a very satisfactory clinical outcome.