Here are some common knee injuries that can occur:

ACL injury
Changing direction rapidly, slowing down when running, and landing from a jump may cause tears in the ACL. Athletes who participate in skiing and basketball, and athletes who wear cleats, such as football players, are susceptible to ACL injuries.

MCL injury
Injuries to the MCL are usually caused by a direct blow to the outside of the knee. These types of injuries often occur in contact sports, such as football or soccer.

PCL injury
The PCL is often injured when an athlete receives a blow to the front of the knee or makes a simple misstep on the playing field.

Torn cartilage
When people talk about torn knee cartilage, they are usually referring to a torn meniscus. The mensicus is a tough, rubbery cartilage that is attached to the knee's ligaments. The meniscus acts like a shock absorber. In athletic activities, tears in the meniscus can occur when twisting, cutting, pivoting, decelerating, or being tackled. Direct contact is often involved.