ACL Tear

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ACL tear

An anterior cruciate ligament (ACL) tear is an injury of the knee joint. It causes leg pain and instability of the knee. ACL tears are common sports injuries. The ACL is one of four major knee ligaments that control stability of the knee joint.

Without an intact ACL, participants in sports often complain of symptoms of knee instability. The ACL does not heal itself when completely torn, and, therefore, surgical reconstruction of the ligament is the usual treatment.

Without undergoing surgical reconstruction of the ACL, athletes will typically have a difficult time returning to certain sports. Some activities such as cycling, swimming, and even jogging, may be possible to return to, even at high-performance levels. However, athletic activities that involve cutting, pivoting, and side-to-side movements generally require a functioning anterior cruciate ligament. For this reason, most high-level athletes will undergo ACL reconstruction in order to regain sufficient stability in their knee to allow resumption of athletic activities.

Right knee, seen from an angle between anteriorly and laterally.

Grading ACL Tears

ACL sprains are graded based on how much the ligament is damaged.

  • A Grade 1 sprain is a minor stretching to the ligament and your knee is still fairly stable.
    • The fibers of the ligament are stretched, but there is no tear.
    • There is a little tenderness and swelling.
    • The knee does not feel unstable or give out during activity.
    • No increased laxity and there is a firm end feel.
  • A Grade 2 is a partial ACL tear, with the ligament stretched so much that it is loose and damaged. These are relatively rare.
    • The fibers of the ligament are partially torn or incomplete tear with hemorrhage
    • There is a little tenderness and moderate swelling with some loss of function
    • The joint may feel unstable or give out during activity.
    • Increased anterior translation yet there is still a firm end point.
    • Painful and pain increase with Lachman’s and anterior drawer stress tests.
  • A Grade 3 sprain, there is a complete tear of the ACL, with the knee joint becoming unstable and surgery almost inevitable if it is to be corrected.
    • The fibers of the ligament are completely torn (ruptured); the ligament itself is torn completely into two parts.
    • There is tenderness, but limited pain, especially when compared to the seriousness of the injury.
    • There may be a little swelling or a lot of swelling.
    • The ligament cannot control knee movements. The knee feels unstable or gives out at certain times.
    • There is also rotational instability as indicated by a positive pivot shift test.
    • No end point is evident.
    • Haemarthrosis occurs within 1-2 hours.

The procedure is called an ACL reconstruction, not an ACL repair

ACLs that are completely torn are generally not repaired, they are reconstructed. The damaged ACL is completely removed as there is rarely potential for healing of a torn ACL. In order to have a functioning ACL, a new ligament must be created. The procedure is called an ACL reconstruction and not an ACL repair.

The orthopaedic surgeon replace the ACL with must undergo “remodeling”, which is a fancy way of saying that it must get weaker before it gets stronger. Your body must grow new blood vessels into the new ACL. These blood vessels take away the old graft fibers, leaving a weakened scaffold.

ACL Tears in female athletes

Research has shown up to an eight-fold increase in the number of ACL tears in female athletes compared with their male counterparts.

The reason for the increased risk has been debated for decades, and experts now believe that it is caused by differences in neuromuscular control. Men and women position the knee differently during critical sports movements such as landing, cutting, and pivoting. The differences in male and female anatomy and hormone levels may also factor into the different rates of ACL tears.

It is certainly reasonable to try nonoperative ACL treatment for a return to some sports

The ACL is one of four major knee ligaments that contribute to knee stability. When an individual tears one of these four ligaments, the knee may become unstable. Some people who tear an ACL don’t have complaints of instability even when doing sports, others have instability episodes with even simple non-sporting activities. Some sports almost always require participants to have an intact ACL, however, many sports don’t. It is certainly reasonable to try nonoperative ACL treatment for a return to some sports.

It’s possible to perform as well as before the surgery

Professional and Olympic-caliber athletes have come back to compete at the highest levels of soccer, football, basketball and other sports. It’s possible to perform as well as before the surgery.

High-level athletes often come back from injury better athletes than before their procedure. Some recent data has shown that athletes coming back from ACL injuries can not only return to their pre-injury level but often exceed where they had been. The most of the athletes historically on the US Ski Team have had their best successes after their first major knee injury.

Elite athletes can regain their sport-specific skills relatively easily. However, they may be able to devote more energy to some aspects of training that have otherwise been neglected. By focusing on core strengthening and flexibility, elite athletes can gain a competitive advantage.


Recent Study On ACL Tear Recovery From The French Ski Team

Return to Sport Among French Alpine Skiers After an Anterior Cruciate Ligament Rupture: Results From 1980 to 2013

The French Alpine Ski Team has published a study showing that longer careers and more successes were seen in French athletes that had torn their ACL at some point during their career.

Highlights of the study:

  • According to the study, 23% of their athletes that had torn their ACL at some point had achieved a podium in their career.
  • Just 8% of their athletes that had never torn their ACL ever achieved a podium.
  • More than 3x as many podiums were achieved in athletes AFTER ACL tear recovery.