Bone marrow edema is a sign with bone matrix edema, fibrous tissue hyperplasia and inflammatory cell infiltration as the main pathological manifestations. With the development of technology and the widespread use of MRI, the sign of bone marrow edema has gradually been recognized, but it has not attracted widespread attention until recent years when some scholars have reported relevant studies. The causative factors of bone marrow edema are still uncertain, including: trauma, hormones, and mechanical stress alterations. Biomechanical alterations are one of the causes of bone marrow edema, and mechanical stress may play an important role in the development of bone marrow edema. Mechanical stress alterations lead to trabecular fractures in the weight-bearing area and the development of bone marrow edema. MRI is currently the best means of diagnosing and evaluating bone marrow edema. The degree of pain is consistent with the severity of bone marrow edema, and as the severity of bone marrow edema decreases with MRI, the patient’s pain decreases accordingly. Specifically, in this case, it should be a patellofemoral problem, caused by increased stress on the patella due to excessive repetitive knee flexion activities, which is rare and easily misdiagnosed. Bone marrow edema syndrome usually occurs in the hip joint. The first and foremost treatment is to limit knee flexion (especially deep knee flexion), kicking and jumping movements, otherwise the effectiveness of treatment will be greatly reduced, and oral NSAIDs such as celecoxib and ibuprofen are administered. Physical therapy such as tui na, ultrashort wave, etc., and external application of Chinese herbs are effective. Generally, surgery is not required. After pain relief, training exercises cannot be resumed immediately, and it is necessary to gradually resume sports after a period of time, but attention must be paid to avoid forms of sports that aggravate patellar injury.