Background - Injury to the anterior Cruciate ligament (ACL) is one of the most common Ligamentous disruptions in the knee. Research has provided much information about the ACL during the past 25 years, but there has been little attention paid to the causes and prevention of injury. Approximately 250,000 ACL injuries occur in the United States each year, or 1 in 3000 of the general population. If it is assumed that at least one third of ACL-injured patients require surgery, then the estimated annual cost is about $1.5 billion, or $17,000 per reconstruction. (ACL injury accounts for overhalf of all sport-related the injury costs to those players) However, this total does not include the costs of initial evaluation and treatment, or the future medical treatment of patients in whom posttraumatic arthritis develops (ACL injury is one of the major reasons for a prolonged inability to complete, can lead to significant problems with work, recreation, and activities of daily living, and can cause subsequence knee injury, pain, and athritis). The significant financial impact and emotional toll of ACL injury make the development of prevention strategies essential. The etiology and prevention of non-contact ACL injury, which has increased dramatically among women, were explored.
The history is characteristic.
- Cutting or pivoting
- Landing or decelerating
- Awkward or off-balance move
- Land on injuries knee near full extension
- Hear a "pop"
- Cannot continue play
- Swelling within a few hours
Overview - There are four categories of etiologic theories for the development of non-contact ACL injuries; hormonal, anatomical, environmental, and neuromuscular. Results of recent epidemiologic studies have showed a significantly higher rate of ACL injury in female athletes compared with male athletes. The difference is particularly evident in basketball and soccer. Two to 8 times more ACL injury are sustained by women than by men in the same sport. It has been hypothesiezed that hormones such as estrogen may predispose female athletes to ACL tears because estrogen can relax soft tissue. Increases in estrogen levels that occur midway through the menstrual cycle may diminish the tensile strength of the ACL. Impingement of the ACL against the intercondylar notch has been postulated as an anatomical cause of ACL injuries. The wider pelvis and the greater average Q-angle in women have been postulated as contributing factors in ACL disruption because the knee is placed in a more valgus or unstable position.
Preliminary studies have demonstrated that women have greater knee and muscle laxity than men, so female athletes with above-average hamstring flexibility may have a diminished protective ability in that muscle group. Environmental factors that may contribute to ACL disruption include the wearing of cleats positioned at the edges of the sole, with smaller pointed cleats positioned interiorly. Uneven playing surfaces and gender variations in athletic posture and movement patterns may also be contributing factors in ACL injury.
Conclusion - Prevention programs that involve proprioception; plyometrics; strength training; and improved stopping, turning, and jumping techniques have demonstrated promising results for the prevention of non-contact ACL injuries. Additionally, muscle activation during the athletic movements related to ACL injury to be characterized by high-level quadriceps muscle activity just before foot strike, together with a low level of hamstring muscle activity and low angle of knee flexion at foot strike.
Whether early active or passive mobilization is better in treatment of anterior cruciate ligament (ACL) injuries is controversial because of lack of information about the forces carried by the ligaments or ligament grafts during various exercises. Cruciate ligament forces were calculated during typical rehabilitation exercises and mathematically from non-invasive in vivo experimental measurements.
Peak ACL force occurred at the knee angles of 35 to 40 degrees. Peak posterior cruciate ligament (PCL) force occurred at a knee angle of 90 degrees. During Isokinetic and isometric extension, the PCL was loaded throughout the range with the peak PCL force still occurring at 90 degrees. There was no ACL force during flexion. Forces on the ACL at knee angles less than 50 degrees were small. At large knee angles, the PCL was loaded. The peak force occurred near the lowest point of the squat. Peak ACL force decreased significantly during Isokinetic extension as speed increased, whereas during Isokinetic flexion, peak PCL force decreased with increasing speed. The difference in peak PCL force was significantly different between the 3 types of squats during the ascending phase.
For ACL rehabilitation, squats are safer than Isokinetic extension for quadriceps strengthening, and Isokinetic flexion is safe for hamstring strengthening. For PCL rehabilitation, Isokinetic extension is safe for quadriceps strengthening if flexion angles are 80 degrees or less. Shallow squats can be used to strengthen hamstring muscles so long as knee flexion angle is less than 50 degrees. Additionally, rehabilitation programs for PCLs should avoid Isokinetic extension at knee angles greater than 70 degrees Isokinetic flexion, and deep squats.
Rehabilitation Emphasis;
- Early extension
- Patellar mobilization
- Quadriceps activation
- Advance physical activities as tolerated
- Brace use not essential