Anterior cruciate ligament(ACL) tear is one of the common injuries in Athletes. It can happen in professional athletes as well as during recreational sports. Unfortunately in India most common cause of ACL tear is 2wheeler accidents. Let us understand the structure of knee before getting into to details of ACL tear.

Knee joint is formed by lower end of thigh bone and upper end of shin bone which are lined by cartilage which smoothens the knee movements. They are connected by few ligaments which gives stability to the knee. The ligaments are,

a) Anterior cruciate ligament (ACL) is in the middle of the knee. It prevents the shin bone from slipping out in front of the thigh bone.

b) Medial collateral ligament (MCL) runs along the inside of the knee and prevents the knee from bending in.

c) Lateral collateral ligament (LCL) runs along the outside of the knee and prevents the knee from bending out.

d) Posterior cruciate ligament (PCL) works with the ACL. It prevents the shin bone from slipping backwards under the femur.

Examination by an Orthopaedic doctor is essential to confirm the diagnosis. Multiple tests are done on your knee to confirm the diagnosis. Clinical evaluation can often be difficult in painful knee and diagnosis can be missed.

MRI is accurate in detecting an ACL tear as well as in identifying associated injuries.

First Aid:
First aid for an ACL injury includes-

  • Do NOT move your knee if you have had a serious injury
  • Use a splint/knee brace to keep the knee straight until you see a doctor
  • Do NOT return to play or other activities until you have been treated
  • Raising your leg above the level of the heart
  • Putting ice on the knee
  • Pain relievers such as nonsteroidal anti-inflammatorymedicines
  • You may need:
      o Crutches to walk until the swelling and pain get better
      o Physical therapy to help improve joint motion and leg strength

ACL is torn by a sudden twisting motion(for example, when the feet are planted one way and the knees are turned another).

Their occurrence may be made less likely by-

·        thoroughly warming up before sports,

·        learning to land on the balls of the feet (not flat-footed)

·        Strength training to make the muscles firmer.

ACL tears don’t heal- Generally the first stage in the healing of ligaments, bones or skin is formation of blood clots.  ACL, almost alone among ligaments, doesn’t heal itself. This is because of the presence of an enzyme in the synovial fluid (fluid inside knee joint) that dissolves blood clots so the process of healing doesn’t get initiated at all.

Partial ACL tear are treated with medicines and physiotherapy.

Complete ACL tear- ACL has to be reconstructed surgically since it cannot heal. Nowadays ACL reconstructions are done with arthroscopy(key hole surgery). A person with reconstructed ACL is made to walk just after the surgery. He/She can return to sports 5 to 6 months after surgery. There are many national and international athletes who have undergone ACL reconstruction and they are back to same level of professional sporting activity.

Fate of the knee with torn ACL( ACL deficient knee)
Repeated giving way of knee causes

  1. Tear of meniscus leading to increased pain and locking sensation in the knee
  2. Damage to cartilage causing early onset osteoarthritis of the knee