Meniscus injuries and rotary leg have a certain relationship, meniscus injuries can be caused by the rotary leg, can also be caused by knee sprain, degenerative changes. 1. Loop leg: also known as “O-shaped leg”, when standing, the two knees can not be close together, long-term looping leg may make the lower limbs of the weight-bearing offset, the weight-bearing offset too much, the knee joint medial pressure is too large, resulting in chronic damage to the knee meniscus and cartilage. 2. Knee sprain: the knee joint is half-flexed and rotated inward or outward violently, the meniscus is subjected to rotational shear force, which is easy to cause meniscus injury. 3. Degenerative changes: high incidence of people for athletes, heavy laborers, long-term weight-bearing, cumulative damage, meniscus elasticity becomes weak, the slightest external force can cause meniscus injury. Meniscus injury may also have other causes, it is recommended to go to the hospital in time, improve the examination to clarify the cause of the disease, give targeted treatment or treatment.