Knee Ligament Sprain and Tear Symptoms and Causes
Knee ligament sprains and tears are injuries to any of the four major ligaments in the knee. These ligaments connect the femur (thighbone) to the tibia (shin bone) and include a pair of cruciate ligaments (ACL and PCL) and a pair of collateral ligaments (MCL and LCL).
An injury to the ligament causes the knee to pop and buckle, causing pain and swelling. The anterior cruciate ligament (ACL) is one of the most common ligaments to be injured, often during a sudden twisting motion. The posterior cruciate ligament (PCL) injury usually occurs with sudden, direct impact. The medial collateral ligament is injured more often than the lateral collateral ligament. Stretch and tear injuries to the collateral ligaments are usually caused by a blow to the outer side of the knee.