CNY Orthopedic Sports Medicine, PC: InjuryDetail: Anterior Cruciate Ligament Tear
Injuries and Conditions: Knee: Anterior Cruciate Ligament Tear: Medical Details
The ACL is one of the four major ligaments in the knee connecting the bones of the upper leg and lower leg. The primary purpose of this ligament is to provide stability and to limit excessive forward motion of the lower leg. During vigorous activities like running, turning, or jumping that place considerable stress on the joint, the ACL helps to stabilize and control excessive movement of the knee. Due to the ACL's location and size, it is typically put under more stress than other ligaments and is one of the most commonly injured structures within the knee, 2nd only to the menisci.

Causes of Injury
  • An ACL injury is typically the result of a sudden change in the direction of the knee, which rotates the upper leg against the lower leg. The severity of the injury can vary greatly according to the stress placed on the joint at the time of the injury. An especially forceful twisting motion can completely tear the ACL.
  • Activities like skiing, where the lower leg is fixed to the ski while the upper leg is mobile and able to rotate, can place extreme stress on the knee joint.
  • ACL injuries are also common in any activity like basketball, soccer, and football that involve a combination of running, sudden turning, and stopping.
  • Hyperextension or over-straightening of the leg, forceful cutting, pivoting or stopping actions, can result ininjury. The potential for injury increases significantly if forceful contact (e.g. tackling in football or soccer) occurs when the knee is in any of these positions.

  • Diagnosis
    The initial diagnosis of the injured knee may be difficult because of significant pain, swelling in the joint and spasm of the muscles surrounding the joint. However, a gentle physical examination is usually sufficient to provide a diagnosis. More serious knee injuries, which involve the ACL and/or other ligaments of the knee, may require a delay in examination. The delay will allow the patient to tolerate the movement of the knee necessary for a more thorough evaluation.

    A healthy ACL prevents the lower leg from sliding forward below the upper leg. If the ligament is damaged, the natural movement of the leg will be affected and the knee will become less stable. Excessive movement or range of motion, which allows the lower leg to move forward beneath the upper leg, demonstrates a severely damaged ACL. Less severe injuries will typically not allow this excessive movement, but patients will instead tend to feel pain and demonstrate the swelling similar to a completely torn ACL.It is possible for some patients to significantly injure their ACL, but complain of only minor symptoms; only upon a second or re-injury of their ACL, do some patients seek medical attention.

  • Considerable pain in the knee that does not go away within the first few hours after the injury.
  • Immediate (usually within 24 hours) swelling of the knee.
  • A feeling of unsteadiness and a tendency for the knee to "give way," or even a complete inability to bear weight on the injured leg.
  • An audible "pop" or the perception of something snapping or breaking at the moment of injury.
  • A feeling of "fullness or tightness" in the knee.
  • Anatomy
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     Product Considerations
    Knee: Ligament Brace
    Functional braces are designed to control abnormal motion of an unstable knee. Because ligaments help stabilize the knee, and a torn ligament leads to instability, these braces are also called Ligament Braces. The intent is to allow a previously injured athlete to compete at a higher level than they would otherwise be able to without the brace. The brace is designed to support either a newly reconstructed ligament such as the ACL, or a weakened or injured ligament, which is being treated in a conservative manner. The role of a functional brace is to increase stability to a previously injured knee.

    Type of Injuries:

  • Pre-operative ACL/PCL ruptures/injuries
  • Non-surgical ACL/PCL injuries
  • General knee instability
  • Pre/post joint replacement with ligament instability.

  • NSAIDs
    NSAIDs (Nonsteroidal Anti-Inflammatory Drugs) are a group of drugs used to control pain. This category of medications includes both prescription and common over-the-counter painkillers such as ibuprofen. NSAIDs are effective for many types of pain that can occur because of inflammation of muscles, joints and bones. The drugs work quickly and people often notice some benefit within a few hours of taking the tablet. However, the complete effectiveness of the drug may not be realized for up to four weeks. For each individual, some varieties of NSAIDs are more effective than others. Often, patients will find that one or two varieties are helpful whereas others may not be as effective in controlling symptoms. It is usually necessary to try several brands and continue with the one that is most suitable. NSAIDs can be used to treat:
  • Pain resulting from inflammation or swelling.
  • Pain after injury.
  • Joint pain and arthritis.

  • Knee: Cold Therapy
    Cold therapy is used to reduce pain and swelling and is a convenient method to apply cold to an injured or rehabilitating extremity, such as a knee or shoulder. A cuff fits like a sleeve around the extremity and utilizes cold water supplied by a connected thermos or canister to chill the extremity. Water flow into the cuff can be controlled by different mechanisms. The simplest way is gravity; elevating the canister fills the cuff and controls the amount of pressure against the extremity. Water flow may also be controlled by a pump which will automatically circulate the cold water to and from the cuff. After surgery or immediately following an injury, the canister should be refilled with cold water every one to two hours to maintain a proper temperature. The cold therapy may also be used during rehabilitation, especially after physical activity, reducing the inflammatory heat from exercise.

    Cold therapy can be used to treat: Knee, Shoulder, Elbow, Wrist and Hand, Back, Hip, and Foot & Ankle Injuries.

    Knee Examples include:

  • Pre-operative ACL/PCL injuries.
  • Non-surgical ACL/PCL injuries.
  • General knee pain or swelling.
  • Soft tissue injuries.

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