An anterior cruciate ligament injury is the over-stretching or tearing of the anterior cruciate ligament (ACL) in the knee. A tear may be partial or complete.

An ACL injury can occur if you:

• Get hit very hard on the side of your knee, such as during a football tackle
• Overextend the knee joint
• Quickly stop moving and change direction while running, landing from a jump, or turning
• Basketball, football, soccer, and skiing are common sports linked to ACL tears.

Early symptoms:

• A "popping" sound at the time of injury
• Knee swelling within 6 hours of injury
• Pain, especially when you try to put weight on the injured leg
• The knee swelling within the first few hours of the injury. This may be a sign of bleeding inside the knee joint. Swelling that occurs suddenly is usually a sign of a serious knee injury.
• Limited knee movement because of pain or swelling or both.
• The knee feeling unstable, buckling, or giving out. If the foot is cool and blue after a knee injury, the knee joint may be dislocated, and blood vessels to the foot may be injured.

MRI

• Raising your leg above the level of the heart
• Putting ice on the knee
• Pain relievers such as nonsteroidal anti-inflammatory drugs (such as ibuprofen)

• Do NOT move your knee if you have had a serious injury.
• Use a splint to keep the knee straight until you see a doctor
• Do NOT return to play or other activities until you have been treated.

• To improve joint range of motion
• To improve strength of muscles strenthening exercises are required.
• To reduce pain, advance modalities are given.
• Use knee braces.

If there is a complete tear then surgical reconstruction of ACL is done.

• Tendons, such as the patellar tendon and hamstring tendon, can be used for autografts.
• The Achilles tendon, patellar tendon and hamstring tendon can be taken and used for allografts.
• Autograft ACL Reconstruction
• Allograft ACL Reconstruction

post operative physiotherapy is required for complete recovery.