The treatment of posterior horn tear of the medial meniscus of the left knee depends on the specific situation. Braking, surgical treatment and the use of non-steroidal anti-inflammatory drugs such as ibuprofen extended-release capsules can be chosen. 1. Braking: For MRI-indicated posterior horn tears of the medial meniscus of the left knee with degree I or II injury, conservative treatment is usually adopted, local braking is recommended, and activities such as exercise, squatting and sharp twisting are avoided. 2. Surgical treatment: For MRI suggests that the posterior horn of the medial meniscus of the left knee is torn at the third degree of injury, and the meniscus has been broken or separated from the whole layer, then it is recommended to carry out arthroscopic surgical treatment, and according to the specific circumstances, choose arthroscopic meniscus repair and suture treatment, meniscoplasty and so on. 3. Use of non-steroidal anti-inflammatory drugs: For those with obvious pain and joint effusion symptoms, non-steroidal anti-inflammatory drugs, such as ibuprofen extended-release capsules, can be used as prescribed by the doctor. The treatment of posterior horn tear of the medial meniscus of the left knee should be determined after specific evaluation by a medical professional.