In everyday life, there is a symptom that is often overlooked. As people’s demand for their quality of life continues to improve and doctors’ awareness of disease prevention and treatment increases, this symptom is gradually being taken seriously by doctors and patients. Jiang Yongfa, Department of Orthopedics, Guangzhou Huadu District People’s Hospital What is this symptom like? In which groups of people does it occur? What is the diagnosis? How to treat? What is the effect of treatment? Please read on with these questions. Symptoms: pain when squatting or standing up from a seat, cycling, climbing, going up and down stairs, and no symptoms at all when walking. People with these symptoms tend to be concentrated between the ages of 35 and 55, and are mostly young and middle-aged women. Because it does not affect walking, many patients pay little attention to it in the early stages of the lesion. On the other hand, because this disease does not have any abnormal findings on routine x-ray examinations, our doctors do not pay enough attention to it and do not intervene actively at an early stage, delaying treatment and leading to an aggravation of the disease. Diagnosis: So what exactly is this disease? By what method can early diagnosis be made? Firstly, the medical history features: squatting pain, walking painless; secondly, special signs (signs are what the doctor sees on physical examination): patellar grinding test (+); the affected joint can induce anterior knee pain when flexing the knee to 30~90 standing so that it cannot be maintained. MRI examination can reveal abnormal signal changes in patellar cartilage. As long as the above-mentioned manifestations exist, the clinical diagnosis of “chondromalacia patellae” or “patellofemoral arthritis” can be made. Of course, the gold standard is arthroscopy. What are the pathological changes of this disease? What is the prognosis? The patella is the largest bone in the body and forms the patellofemoral joint with the femur, which is an important part of the knee joint. The presence of the patella gives greater strength to straighten the thigh. The joint surface of the patella has a thick layer of articular cartilage, up to 6 mm thick, and this shiny layer of cartilage has two main functions: first, to reduce the friction between the bones during relative movement, so that our knee joint can move more smoothly; second, to cushion the pressure and avoid the impact between the bones. When we eat pig’s feet joints in our daily life, we see a layer of bright and smooth ceramic, a certain degree of hardness of the tissue is equivalent to the cartilage of human joints. In the role of a variety of factors: such as age, accidental injury can make our layer of joint cartilage damage. Once the cartilage is damaged, the friction between the bones is greatly increased, and the ability to cushion the impact is greatly reduced, inevitably causing soreness and pain. Because this layer of hyaline cartilage is transparent to X-rays, no abnormalities are found in the early and middle stages of the disease before the thickness of the cartilage is changed. According to the pathogenesis of the disease, it is not difficult to understand our treatment and preventive measures: 1. change the position and movement that cause the aggravation of the lesion; for example, change from squatting to sitting, avoid climbing and reduce stairs. 2. take oral nutritional drugs for joint cartilage: glucosamine; intra-articular injection of joint “lubricant” such as sodium vitrate, etc. The latest techniques include platelet-rich plasma (PRP), 3. arthroscopic chondroplasty, 4. articular cartilage grafting, and 5. patellofemoral arthroplasty. The above measures are a stepwise approach to the treatment of this lesion, but increasing the attention of both the patient and the physician is essential to keep the lesion to a minimum. Illustration: The blue arrow in the top figure shows a bulging and cracked cartilage injury; the blue arrow in the bottom figure shows a completely cracked and defective cartilage with partially exposed subchondral bone. This article is authorized by Dr. Jiang Yongfa.