Patient: The patient was diagnosed with chondromalacia patellae in both knees at Xi’an Xijing Hospital in November 2000 due to long-term soccer practice, and the MRI reported a small amount of effusion, which resolved in 2002 after a year of rest. However, in May 2009, he suffered pain in both knees due to participating in the 20m “bridge crossing” (a kind of crouching and crawling competition) in the school sports event. Every day, I had to go back and forth to my unit and home, and my home and unit were both high-rise, so I went up and down the stairs too often. On September 16, due to repeatedly squatting down to repair the computer, I felt pain in both knees and could not walk fast enough. After barely 2 days, both knees were already fatigued to the limit, and on September 19, I washed and compressed with hot water, and the pain from going up and down the stairs was so bad that I felt weak and heavy in both knees, stabbing pain, and couldn’t walk fast enough to beat my weak legs. On October 12, I went to Gansu Provincial Hospital of Traditional Chinese Medicine and was diagnosed with chondromalacia patellae in both knees. During this period, CT films of both knees were taken. He started to take glucosamine hydrochloride tablets (Glucophage) for 12 weeks from September 20, but the effect was not obvious. However, I did not rest for 2 weeks when the pain started, which made it worse day by day. (During this period, I put an anti-depressant cream on both knees and took Antamaxin for 3 days.) On October 1, I started to take Cilazep for 2 weeks, 1 capsule a day. On October 12, I received 5 injections of sodium vitaminate in each knee, once a week, and by November 22, the effect was still obvious. My legs feel better when I walk, but I walk slowly and have to support the stairs when I go up and down. Only 2 days before the first injection, I accidentally strained my right knee slightly (sitting in front of the computer with my leg tilted on the bed, and strained it when I drew my leg downward, but it stopped hurting after 1-2 days of rest. After November 22, three weeks after starting straight leg raising exercise, and adding the action of pressing the bed with the leg, the inner side of the right knee started to hurt, so I gave up exercising muscle strength and found that it hurt to press the middle of the inner side of the right knee with my fingers, which affected the pain of walking and limping in the right knee. I used diclofenac sodium for 2 weeks and 2 boxes of Fotarine ointment, followed by 3 weeks of fumigation with herbal lotion, and my right knee got better. On January 18, 2010, I started to do acupuncture and IF 10 times on both knees. During this period, I felt less painful walking and my gait was faster. Then I started Chinese herbal fumigation for 1 week, but the effect was not good, and my legs started to feel weak again, and my legs were weak. It may be due to excessive heat application or too much activity during this period. I rested at home and took Fotarine for about 1 week to relieve the symptoms, so on February 15, 2010, I started muscle strength exercises and did squatting exercises for 1 week, 3 times a day for 30 minutes, but my right knee started to hurt first, and both knees started to walk weak and tender again, and then stopped. It’s been 12 months since my onset, and I can barely walk to work, and I have to climb up and down stairs every day. From March 8, I started to do ultrashort wave in the Army General Hospital for a total of 3 treatments, one in June and one in September. I took diacerein for 3 months, and performed straight leg raising exercise, and took axial radiographs, which reported that no significant abnormality in bone quality was seen. Now it is about 5-6% recovery. The doctor checked and said there was no fluid accumulation. The pain was not obvious when grinding with the palm of the hand in the sitting position with both knees straightened, and there was no obvious pressure point when pressing with the fingers. The right knee muscle was worse than the left. It was also said that it was not indicated for surgery, but it was possible to have surgery. Now I walk slowly and feel fatigue and weakness after walking for more than 20 minutes. I still have to hold the stairs every day to go up and down. There has been no significant swelling in both knees. Sitting for a long time also makes me feel uncomfortable. Exercise muscle strength intermittently, 2 straight leg lifts per day for 30 minutes at a time. Symptoms also come and go, can’t stand strain and wind chill, also easily sprained, especially right knee, once painful, had to interrupt exercise and turn to medication or physical therapy to relieve symptoms. I had to interrupt my workouts and take medication or physical therapy to relieve the pain. I could barely go to work. During the school holidays, I rested during the holidays and felt the effect was obvious, and my walking was close to normal, but once I went to work and strained myself, I regressed. Now my right leg twisted again while riding in the car, and I am walking with a limp again. I’m planning to take another injection, but is this the right time? I am afraid to practice squatting, so please help me. Doctor: After reading your brief description of your condition, I would like to give you some advice. First of all, chondromalacia patellae is not an academic diagnosis that accurately reflects patellofemoral cartilage and patellofemoral joint pathology. The so-called patellofemoral joint is the contact surface between the cartilage on the inner surface of the patella and the cartilage of the femoral talus. Based on your brief description, I think it’s an exfoliative osteochondritis of the patella and femoral cartilage, or also known as patellofemoral arthritis. The pathogenesis is as follows:1 Developmental problems, mainly in women of yellow ethnicity, have a higher chance of patellar hypertelorism, knee valgus (increased Q angle of the knee joint), medial femoral muscle hypoplasia, femoral epicondyles hypoplasia and patellofemoral typing type 2-5, etc. The end result is a poor patellofemoral joint match, resulting in unbalanced medial and lateral patellar contact when the patella moves on the femoral cartilage. The patella is skewed to the lateral side, only the lateral half of the patella is working, the medial half is less weight bearing, and under the same conditions, such people are prone to patellofemoral joint cartilage problems.2 Occupational factors or inappropriate exercise patterns. Beach volleyball, mountain climbing and other sports, if engaged in for a long time, can cause the patellofemoral joint cartilage to wear out beyond its ability to repair, just like the static squat training you do.3 Trauma is also a factor in the pathogenesis. As for the examination, I think the main thing is the doctor’s clinical examination, the front and side films of the knee joint and the CT of the knee joint at 30 degrees of flexion are sufficient, the MRI of the knee joint is not very helpful for the etiology of this disease. In addition, you should also check the meniscus, the second degree of fading generally has few symptoms, and the accuracy of MR is only 88%.