The anterior cruciate ligament, or ACL, is one of the major knee ligaments that is located in the middle of the knee and runs from the femur (thigh bone) to the tibia (shin bone). It prevents the tibia from sliding out in front of the femur. Together with posterior cruciate ligament (PCL) it provides rotational stability to the knee.

An ACL injury is a sports related injury that occur when the knee is forcefully twisted or hyperextended. An ACL tear usually occurs with an abrupt directional change with the foot fixed on the ground or when the deceleration force crosses the knee. Changing direction rapidly, stopping suddenly, slowing down while running, landing from a jump incorrectly, and direct contact or collision, such as a football tackle can also cause injury to the ACL.

When you injure your ACL, you might hear a “popping” sound and you may feel as though the knee has given out. Within the first two hours after injury, your knee will swell and you may have a buckling sensation in the knee during twisting movements.

Diagnosis of an ACL tear is made by knowing your symptoms, medical history, performing a physical examination of the knee, and performing other diagnostic tests such as X-rays, MRI scans, stress tests of the ligament, and arthroscopy.

Treatment options include both non-surgical and surgical methods. If the overall stability of the knee is intact, your doctor may recommend nonsurgical methods. Non-surgical treatment consists of rest, ice, compression, and elevation (RICE protocol); all assist in controlling pain and swelling. Physical therapy may be recommended to improve knee motion and strength. A knee brace may be needed to help immobilize your knee.

Young athletes involved in pivoting sports will most likely require surgery to safely return to sports. The usual surgery for an ACL tear is an ACL reconstruction which tightens your knee and restores its stability. Surgery to reconstruct an ACL is done with an arthroscope using small incisions. Your doctor will replace the torn ligament with a tissue graft that can be obtained from your knee (patellar tendon) or hamstring muscle. Following ACL reconstruction, a rehabilitation program is started to help you to resume a wider range of activities.

Posterior cruciate ligament Injury
Posterior cruciate ligament (PCL), one of four major ligaments of the knee is situated at the back of the knee. It connects the thighbone (femur) to the shinbone (tibia). The PCL limits the backward motion of the shinbone.

PCL injuries are very rare and are difficult to detect than other knee ligament injuries. Cartilage injuries, bone bruises, and ligament injuries often occur in combination with PCL injuries. Injuries to the PCL can be graded as I, II or III depending on the severity of injury. In grade I the ligament is mildly damaged and slightly stretched, but the knee joint is stable. In grade II there is partial tear of the ligament. In grade III there is complete tear of the ligament and the ligament is divided into two halves making the knee joint unstable.

The PCL is usually injured by a direct impact, such as in an automobile accident when the bent knee forcefully strikes the dashboard. In sports, it can occur when an athlete falls to the ground with a bent knee. Twisting injury or overextending the knee can cause the PCL to tear.

Patients with PCL injuries usually experience knee pain and swelling immediately after the injury. There may also be instability in the knee joint, knee stiffness that causes limping, and difficulty in walking.

Diagnosis of a PCL tear is made on the basis of your symptoms, medical history, and by performing a physical examination of the knee. Other diagnostic tests such as X-rays and MRI scan may be ordered. X-rays are useful to rule out avulsion fractures wherein the PCL tears off a piece of bone along with it. An MRI scan is done to help view the images of soft tissues better.

Treatment options may include non-surgical and surgical treatment. Non-surgical treatment consists of rest, ice, compression, and elevation (RICE protocol); all assist in controlling pain and swelling. Physical therapy may be recommended to improve knee motion and strength. A knee brace may be needed to help immobilize your knee. Crutches may be recommended to protect your knee and avoid bearing weight on your leg.

Generally, surgery is considered in patients with dislocated knee and several torn ligaments including the PCL. Surgery involves reconstructing the torn ligament using a tissue graft which is taken from another part of your body, or a cadaver (another human donor). Surgery is usually carried out with an arthroscope using small incisions. The major advantages of this technique include minimal postoperative pain, short hospital stay, and a fast recovery. Following PCL reconstruction, a rehabilitation program will be started that helps you resume a wider range of activities. Usually, a complete recovery may take about 6 to 12 months.

Medial Collateral Ligament Injury
The medial collateral ligament (MCL) is the ligament that is located on the inner part of the knee joint. It runs from the femur (thighbone) to the top of the tibia (shinbone) and helps in stabilizing the knee. Medial collateral ligament (MCL) injury can result in a stretch, partial tear, or complete tear of the ligament. Injuries to the MCL commonly occur as a result of a pressure or stress on the outside part of the knee. Anterior cruciate ligament (ACL) may be torn along with a MCL injury.

Patients with an MCL tear have symptoms such as knee pain, swelling, and locking or catching sensation in the knee during movement. Patients may also feel as though their knee may ‘give out’ suddenly or buckle.

Your doctor will usually diagnose an MCL injury based on a physical examination of your knee. To determine looseness of the ligament, an MCL test may be performed by exerting pressure on the outside of your knee while your knee is bent to 25 degrees. In addition, other tests such as knee joint X-rays and MRI scan may be done.

Treatment options include non-surgical and surgical treatment. Non-surgical treatment consists of rest, ice, compression, and elevation (RICE protocol); all assist in controlling pain and swelling. A knee brace may be worn to help immobilize your knee. Use of crutches may be recommended to protect your knee and to keep you from putting weight on your knee while walking. Physical therapy exercises may be recommended to improve knee motion and strength.

Most often, surgery is not necessary for the treatment of an MCL tear. If needed it is usually performed using arthroscopy. In many cases, this injury cannot be prevented. However using proper techniques during sports or exercising can help prevent injury.