The incidence of sports injuries is...

The incidence of sports injuries is upon the rise as more teenagers and adults become involved with sports activities. Anterior cruciate ligament (ACL) tears are becoming more for the use of all among adults and female teenagers because of their increased participation in contact sports, especially with the increase in female soccer players. Although the medial collateral ligament (MCL) is the greatest in number commonly injured ligament of the knee the ACL is the greatest in quantity commonly injured ligament that causes abnormal knee joint laxity. (1) Injury to the ACL without injury to other ligaments offers in approximately 60% of ACL injuries. The classic history of an ACL tear is a unforeseen twisting of the knee at which time the patient hears a explosion or snap. The patient also may complain of a feeling that the knee is giving away. During the initial injury, the ACL may not be the solitary stability structure torn. For example, a belonging to all triad of injuries includes the torn ACL, a medial meniscus tear, and a partial or ended MCL tear.

NORMAL ANATOMY

The knee joint is individual of the largest and principally complex joints in the material part It consists of

* the thigh-bone which meets the tibia to form the main knee joint;

* the patella, a triangular-shaped bone embedded in the tendon of the quadriceps muscle, which is anterior to the knee joint in the intercondylar furrow of the distal femur; and

* the patellofemoral joint, which is where the thigh-bone joins the patella.

The main knee joint has a medial and lateral compartment encircleed by a joint capsule that is attached proximally to the femoral condyle and distally to the tibial condyle and upper [i]finale[/i] of the fibula.

Ligaments are bundle ups of collagen fibers that provide stability and puissance to the knee joint. The collateral ligaments (ie, medial, lateral) strap the outside of the joint and cruciate ligaments (ie, anterior, posterior) cros within the joint. The bound cruciate comes from the word crux or cros and the word crucial. The cruciate ligaments consist of brace fibrous bands that extend from the intercondylar fossa of the thigh-bone to attachments anteriorly and posteriorly in the intercondylar eminence of the tibia. They crisscross above one another to form an "X" inside the knee The ACL combines the anterior surface of the tibia to the posterior surface of the thigh-bone and is crucial for preventing the knee from sliding forward. The posterior cruciate ligament (PCL) provides opposing support from passing anteriorly and medially (Figure 1) The capsule also is reinforced in brass by the patellar and quadriceps tendons and posteriorly at the popliteus and gastrocnemius muscles.

[FIGURE 1 OMITTED]

The menisci (ie, thickened cartilage pads) are inserted between the femoral and tibial condyle and attached to the joint capsule. Menisci are almost totally avascular; therefore, degenerative changes usually are permanent. The suprapatellar bursa is situated between the tendon of the quadriceps femoris muscle and the anterior surface of the lower section of the femoral portion of the knee joint. Synovial membrane (ie, a sheet of flattened connective tissue cells) lines the capsule of the joint and screens the infrapatellar fat pad, parts of the cruciate ligaments, and portions of the thigh-bone and tibia. (2)

Functional Anatomy

Normally, the knee flexe to a maximum of 135 qualitys and extends to zero qualitys The two joints formed from the femur and tibia have a meniscus between them that acts as a plane surface on which the joint can determine Bursa (ie, fluid-filled sacs) environ the knee joint to provide a gliding surface to shorten friction of the tendons, like as friction of the patellar tendon that attaches to the effrontery of the tibia below the kneecap. Large vital current vessels pass through the popliteal space behind the knee The quadriceps muscle increases the knee joint, and the hamstring muscle flexe the knee joint.

The average adult ACL is approximately 35 cm prolonged It has a semicircular attachment at the posterior portion of the medial aspect of the lateral femoral condyle The ACL lies in an anteromedial and distal direction, making an outward spiral and inserting near the anterior spine of the tibial plateau. The tibial attachment usually is 15 cm posterior to the anterior articular surface of the tibial plateau. The ACL, like the PCL is an extrasynovial form and yet it is located intra-articularly.

The ACL provides a primary restraint to anterior tibial translation upon the femur and acts as the major secondary restraint to medial tibial displacement. It provides stabilization to valgus and varus opening, as well as to internal and external rotation.

MECHANISM OF INJURY

The principally common method of injuring the ACL happens without the knee coming in contact with another thing This kind of noncontact injury usually happens when the human frame changes direction rapidly so that, with the knee in sated extension, the femur is rotated externally onward a fixed tibia. Landing in succession a straight leg or attempting to make an abrupt stop also can torque the knee in this manner, causing an ACL injury. These kinds of injuries are general in basketball, football, volleyball, and soccer Skiers and snow boarders also can experience this kind of injury because the lower extremity and ankle is locked into a make difference preventing the person from relieving the unlooked for torque on the knee. Also, the ACL frequently is injured by a direct misfortune of excessive lateral force to the knee This valgus stres forces the knee into an abnormal position, tearing the ACL and other knee structures