What do you think about a degree I-II meniscus injury? I often get asked: How do you say that there is no problem when the MRI says that the meniscus of the knee is degree I-II damaged? At most, the clinical doctor will explain this question once, or even not at all. After I explain it here, I hope that the netizens will not ask similar questions again. They all go for tests, films, MRI of the knee, etc., because they have discomfort or pain in the knee, hoping to get a clearer picture of the cause. But it must be clear: an imaging report is not the same as seeing a doctor. You must be able to use imaging and test results to explain the patient’s current symptoms in order to find the cause. There are many causes of knee pain and discomfort, some of which are complex, and they fall into three general categories: first, problems within the knee joint, such as meniscal injury, articular cartilage injury, synovial inflammation, ligament injury, bone contusion, patellofemoral instability, etc.; second, problems around the knee joint, such as periprosthetic bursitis (goose foot bursitis is the most common), periprosthetic ligament strain, periprosthetic cyst, periprosthetic muscle Third, non-knee problems can also cause peri-knee discomfort, such as femoral head necrosis (about 20% of first symptoms are knee pain), lumbar disc herniation/spinal stenosis, cervical spondylosis (lower limb stiffness/softness), cerebrovascular disease, rheumatic immune disease, gynecological disorders, etc. Clinicians and joint surgeons determine the cause of the patient’s knee pain/discomfort through a combination of history taking, physical examination, imaging analysis, and laboratory tests, and then make recommendations for the next step of examination, treatment, rehabilitation, and health care. Imaging is a very important diagnostic reference nowadays, and MRI is expensive, clear, and trustworthy, but still cannot replace the clinician’s comprehensive analysis and judgment, which requires very rich clinical experience, especially general practice knowledge. I often see patients in outpatient clinics who have been treated elsewhere for several sessions with poor results and, upon closer examination, discover that: the abnormality reported by the imaging is not the cause of the patient’s pain. Rather, it is other diseases, such as cervical spondylosis, lumbar disc herniation/spinal stenosis, femoral head necrosis, rheumatoid arthritis, cerebrovascular disease, bursitis, etc., which, when treated according to meniscal injury or knee osteoarthritis, certainly do not achieve significant relief. The diagnosis of meniscal injury inferred by the joint surgeon can be considered as follows: meniscal injury is the main cause of the patient’s knee pain/discomfort. In contrast, a meniscal injury reported by an imaging department indicates that: the patient has imaging signs of meniscal injury or degeneration, but not necessarily the cause of the patient’s knee pain/discomfort. MRI imaging classifies meniscal injury into four degrees: degree I injury as an edematous signal within the meniscus, degree II injury as an irregular signal within the meniscus that does not reach the articular surface of the meniscus, degree III injury as an irregular signal within the meniscus that reaches the articular surface, and degree IV injury as a signal of significant abnormalities in the meniscus morphology. Moreover, long-term clinical data from home and abroad show that it is very common for the meniscus to degenerate after young adulthood, with I-II degree signal changes; it is also very common for middle-aged and older adults to have III-IV degree injuries; however, most do not cause discomfort in the knee joint. Even in adolescents, early signs of meniscal degeneration are often seen in those who participate in strenuous sports/work and do not cause symptoms; in children under 10-12 years of age, the meniscus should not show signs of degeneration, and a grade I-II injury can be considered a true injury, and most will heal spontaneously with conservative treatment. Just because the imaging surgeon must write up the abnormality he sees does not mean it is the direct cause of the patient’s knee pain and discomfort; the same goes for other specialties. Therefore, when a joint surgeon sees “I-II degree damage/or degeneration of the meniscus of the knee,” he or she basically assumes that the meniscal damage is not the cause and that further testing or other causes need to be considered. Either that or there is no obvious problem.