Injuries to this ligament are common. The ACL crosses the center of the knee joint. It connects the femur (thigh bone) to the tibia (shin bone), helping to control knee rotation and forward movement of the tibia. The ACL can stretch or tear during sudden slowing or stopping. It can also be injured while pivoting with the knee with the foot held in one place. Such movements occur often in sports like soccer, basketball and skiing. This ligament can also be injured if there is a direct blow to the knee from one side. This happens in sports like hockey and football.
The first symptoms of an ACL injury may include:
Not everyone experiences all of these problems. Certain symptoms like pain and swelling can also occur with other types of knee injuries.
The PCL also crosses the center of the knee joint, just behind the ACL. It balances the ACL by controlling backward movement of the tibia. The PCL is much less likely to be injured than the ACL and usually injured by a direct blow to the tibia below the knee. For instance, hitting the shin against the dashboard in a car crash or falling onto a bent knee during a football game can do damage.
Symptoms of a PCL injury may include:
Unlike ACL injuries, a pop is not usually heard or felt. Nor is there the same sense of instability. Pain and swelling may be very mild. Instead, there may only be a vague sense that something is wrong.
The MCL is on the medial (or inner) side of the knee. It connects the inner surfaces of the femur and the tibia. The MCL stabilizes the inner side of the knee joint, preventing widening or ‘opening’ of the knee joint on the inside. Injury to the MCL can occur if the outside of the leg, knee, or lower thigh is struck, as when clipped in football. It may also be injured with pivoting or twisting movements in sports like skiing.Symptoms of a MCL injury may include:
The severity of symptoms depends on the extent of the damage. Only with more severe MCL injuries will the knee feel unstable.
This ligament is on the outside of the knee, opposite the MCL. It connects the lateral (outer) surfaces of the femur with the fibula, the outer bone on the lower leg. It stabilizes the outer side of the knee joint, helping to prevent widening or ‘opening.’ Less likely to be injured than the MCL, a direct blow to the inner surface of the knee can injure the LCL.
Symptoms are similar to that of a MCL injury, except on the outer area of the knee. As with injury to the MCL, severity of symptoms depends on the extent of injury.
It is possible to damage more than one ligament, depending on how the knee is hurt. Other structures in the knee, such as the surface and meniscal cartilage, can also be injured.
Diagnosing ligament injuries of the knee starts with a thorough history of the injury. Your doctor will ask you several important questions. These may include the following.
Your doctor may ask other questions about your medical history and any previous knee injuries.
Next, the knee will be examined. Your doctor will assess the amount of knee swelling, range of motion, and location of pain. Several different tests can check the ligaments. Doctors often compare a hurt knee to the uninjured one.
Questioning and a physical exam can diagnose most ligament injuries. A doctor may sometimes order diagnostic imaging tests like x-ray, ultrasound, bone scan or MRI to further evaluate the injury.
Initial treatment for most ligament injuries involves controlling pain and swelling, and recovering knee range of motion. Changing your activities, resting, and applying ice is usual. Pain killers or anti-inflammatory medications may be recommended. Depending on the ligament injured and the amount of damage, other treatment options may include:
In considering surgery, you and your doctor will discuss:
Even with a serious injury, with appropriate treatment it is usually possible to fully recover and return to most sport and work activities. Your doctor can discuss in detail a treatment plan that works for you.
There is growing evidence that you can train your body to avoid some knee ligament injuries. This is particularly true for ACL injuries. Exercises that may help include those that:
Discuss a suitable exercise program with your doctor or certified personal trainer.