Outpatient clinics often encounter patients with a history of knee sprains who have been in other hospitals where x-rays were taken showing: no fracture was seen. And the diagnosis of soft tissue sprain, long-term medication, but no improvement. Due to the characteristics of the orthopedic department of Maoming Petrochemical Hospital such as minimally invasive arthroscopic technology, the patient often came to our clinic by name and took MRI to know that it was a meniscus injury. The normal meniscus has the function of increasing the concavity of the tibial condyle and padding the inner and outer femoral condyles to increase the stability of the joint and to act as a shock absorber. Injured meniscus, on the other hand, plays a destructive role for the knee joint. Meniscus injury requires arthroscopic surgery as soon as possible. The orthopedic department of Maoming Petrochemical Hospital is very famous for its minimally invasive arthroscopic surgery. When we perform arthroscopic surgery, we find that meniscal injuries that are found early and operated early have less damage within the joint and smoother cartilage; while many patients who have been delayed for several years have a premature osteoarthritis and increased cartilage wear within the knee joint due to meniscal injury and constant wear and tear on the knee joint. Therefore, we recommend that for knee injuries, you need to come to the hospital as soon as possible. If you still have pain more than one month after a knee sprain, we recommend an MRI examination. If a meniscal injury is diagnosed, arthroscopic surgery is required in a timely manner.