ACL TEAR- ANTERIOR CRUCIATE LIGAMENT TEARS
An estimated 200,000 cases of anterior cruciate ligament (ACL) tears occur on an annual basis. A large percentage of these injuries are the direct result of sports activities. Activities that involve sudden stop-ping, twisting, or sudden change increase the risk for an ACL tear.
The ACL runs a diagonal course from the femur to the tibia. Its function is to prevent translation (sliding in and out) of the tibia and to provide rotational stability to the knee joint. Injuries can result from di-rect contact and non-contact, as described above. Multiple studies have shown that female athletes have a higher incidence of ACL injuries than males.
There are varying degrees of injury that can occur to the ACL. In a grade I sprain, the ACL has been stretched, but is still able to provide stability. A grade II sprain results in a partial tear of the ACL result-ing in loosening on the joint. A grade III sprain is also known as a complete tear. Significant instability may be present.
A sudden audible “pop” or feeling is a classic symptom of an ACL injury. The knee often becomes unsta-ble immediately and swelling will set in within the first 12 to 24 hours. Internally, bleeding into the joint occurs. Loss of range of motion secondary to pain and swelling may also present. It is estimated that other injuries occur in the knee in conjunction with an ACL injury 50% of the time. These other internal derangements include meniscal and collateral ligament tears.
An ACL tear is usually diagnosed by an orthopaedic surgeon through the obtained history and physical examination. There are specific tests the surgeon will perform during the examination that will aid in diagnosing the injury. A MRI is usually ordered to confirm the diagnosis.
Treatment of an ACL injury may be non-surgical or surgical. A tear will not heal by itself. However, in some patients where stability and function is maintained, non-operative treatment such as bracing and physical therapy to strengthen the leg may be recommended. This is often the case for older patients who are less active.
Surgical treatment of an ACL tear is usually performed by an orthopaedic surgeon who specializes in sports medicine. The surgery involves a reconstruction of the torn ACL. Various surgical techniques are available. A structured rehabilitation program follows surgery with the goal of returning back to activities.