The meniscus is located between the upper and lower articular surfaces of the knee joint and is divided into the medial and lateral meniscus, which are on the lateral and medial sides of the knee joint respectively. The meniscus is often likened to a cushion because it absorbs the impact of sports, stabilizes the knee joint and protects the articular cartilage. However, the meniscus can also be easily torn under excessive adverse stress. Guangzhou Orthopaedic Hospital Sports Injury Department Ye Yongguang Most of the meniscus tissue has no blood supply, so it is difficult to heal itself, but in the peripheral part of the meniscus, there will be nutrient blood vessels distributed, so healing is possible for this part of the tear. The tear makes the originally smooth surface of the meniscus uneven, which can cause pain, swelling and stiffness in the knee joint, sometimes resulting in “interlocking” of the knee joint. Although a person can still walk after a meniscus tear, it is important to see a doctor as soon as possible to get an early examination to determine the location and extent of the injury, otherwise it will cause more trouble with the knee later. The most common posture that causes meniscus damage is to use the affected foot as a fulcrum and twist the knee violently in a semi-flexed position, similar to a kickball. Of course, repetitive squatting and standing, slips and falls, bruises, and aging wear and tear can all lead to meniscal tears. There are several common types of meniscus injuries. For example, radial tears, longitudinal tears, horizontal tears, or “barrel handle” tears can occur individually, or several types of tears can occur together to form a complex tear. There is also a congenital development-related tear called a disc cartilage tear, which often results in limited extension and interlocking of the joint. The location, type, and severity of the tear determine the surgical options. Generally speaking, meniscal tears caused by sports injuries have a more definite history of injury. Patients may experience recurrent knee swelling, pain, and limited motion; sometimes a “weak leg” or a painful popping sound. In some cases, the muscles of the thigh may atrophy and become thin over time. During the visit, the doctor will ask the patient about the history of the injury, the area of pain, and the current condition that is affecting the activity. To prevent missing out, the patient can also prepare a memo to remind him or her before the visit so that the problem can be presented in more detail. There are many conditions involving the knee joint, and to make a differential diagnosis, the doctor will have the patient lie flat on his or her back to examine the knee. One common test is called the “McKinsey test”. The doctor will extend and rotate the knee back and forth, which may cause pain and popping, but the patient does not need to be overly nervous as the experienced doctor will do this in a measured manner. In addition, the patient may be asked to undergo X-rays, magnetic resonance imaging (MRI) and other tests to further clarify the diagnosis. Arthroscopic surgery has become the “gold standard” for treating meniscal tears. Usually arthroscopic surgery requires only 2-3 small incisions of about 0.5 cm in the knee joint. This is a world of difference from the old practice of cutting open the joint and cutting the meniscus completely. For the treatment of a ruptured meniscus, there are two approaches. First, a portion of the meniscus is removed in cases of free edge rupture or severe compound injury, and partial removal is done in older meniscus with degeneration. The other is repair. When the tear occurs in the “red zone,” or “red-white zone,” which is the peripheral portion of the blood supply, repair is chosen at the surgeon’s discretion. The nature of the injury is evaluated in detail during the repair, and a fresh treatment of the injury site is performed, followed by access to special instruments for the repair. Because of the extreme delicacy of the repair instruments and the need to work within a very narrow gap, the procedure is quite difficult and the operator’s inability to master the technique can be more than worth the cost. There are a few things that patients should know about meniscus surgery. Although meniscus surgery is a minimally invasive procedure, you will not be able to move freely within a few days after surgery. Rehabilitation is necessary; the removed portion of the meniscus cannot grow back, but the remaining meniscus can still function as a “cushion”; and recovery from a meniscal tear is slower than from a partial removal. After surgery, patients should generally lie down more often, pay attention to elevating the affected limb, and apply ice packs 2-3 times a day to reduce swelling. Don’t forget about rehabilitation!