Two ligaments in your knee are more prone to injury, the anterior cruciate and medial collateral ligaments. The menisci act as a joint filler, between femoral and tibial surfaces . The menisci have a joint lubrication function, helping to distribute synovial fluid throughout the joint and aiding the nutrition of the articular cartilage. They are important rotary stabilizers of the knee. The ACL may be injured when twisting movements force the knee beyond its normal range of motion.
Partial tears occur, but are less common.
There is pain on squatting on an Indian style commode, or on the ground. The term internal derangement is applied to a variety of intraarticular and extraarticular disturbances, usually of traumatic origin, that interfere with the function of the joint. There is edema and swelling of the periarticular structures. There is involvement of the synovium, the capsule, and the articular cartilage this can eventually result in osteoarthritis. Internal derangements of the knee often are severely disabling unless diagnosed promptly and treated efficiently.