A normal knee has a joint formed by the tibia bone from below, the patella in the middle and femur from above. The patella is held in the middle by four ligaments. These ligaments are Medial Collateral Ligament (MCL), Posterior Cruciate Ligament (PCL), Anterior Cruciate Ligament (ACL) and Lateral Collateral Ligament (LCL). These ligaments hold the knee joint together, which essentially makes it a stable hinged joint. Anterior Cruciate Ligament (ACL) is positioned in the middle and runs diagonally holding the tibia, it function is to provide the stability need during rotation of the knee joint. On the surface, the knee is covered with an articular cartilage that can be found on both sides of the joint. There is lateral and medial meniscus that works as shock absorbers, additional they reduce stress between the femur and tibia bone with the help of the cartilage (Davidson, Wilson, Chalmers, Wilson, & McBride, 2009). A normal knee joint as describe above is expected to look as the diagram below.
According to Peat and et al (2006) a combination of ACL injuries and menisci damage constitute 50% of knee injuries. Damages and injuries to the articular cartilage and ACL constitute about 30% of the knee injury cases. While ACL injuries with collateral ligament injuries make up 30% of the injuries. The frequency of these injuries and damages increases with the type activities an individual engages in. High frequency of knee injuries cases can be found in football players , basketball players ,skiers and sky divers among other sports personalities.
Knee injuries are common among individuals who undertake risky sporting activities, such as skiing, football, basketball, volleyball, cycling or sky diving among other sporting with higher injury risks. According to Peat and et al (2006), more than two hundred thousand people in the USA get knee injuries annually. The most common knee injury is where the ACL ligaments get injured with most of the injuries resulting into surgical reconstruction. Other common knee injuries can result, when the articular cartilage or the meniscus get damaged. It is also not uncommon to find individuals with injured knees, where the surface or beneath the cartilage get bruised. These bruises and injuries may result, when there is a direct contact with objects, hard surface or other individuals, especially during sporting activity (Peat, Thomas, Duncan, Wood, Hay, & Croft, 2006). However, knee injuries can also result from cutting, unbalanced landing or falling among other awkward postures.
Additionally, it is clear that knee injuries can be as a result of non contact damages. Knee injuries can be accelerated by lack of muscular strength, the physical condition of a person or the laxity of the ligaments. To diagnose ACL injuries, a patient can have a physically visible injury or require an x-ray to diagnose a fracture. When the injuries cannot be seen from the X-ray or physically, an MRI (magnetic resonance imaging) scans can be used to check injuries on ligaments, articular cartilage or the meniscus cartilage. A torn ACL can be diagnosed by doing the Lachman’s test. In addition, a torn ACL ligament causes increased anterior movement of the knee joint and the endpoints of the knee become soft and mushy in comparison to a normal knee joint. ACL can also cause the tibia bone to move forward despite the knee joint being straight.
Fractures or cracks in the knee joint bones cause abnormal motion, pain, swelling, crepitation, deformity or ecchymosis. In cases, where the fracture is severe, it can lead to complication that may result in nerve injuries, arterial injury, infection or compartment syndrome. Treating damaged ACL ligaments and knee fractures involve immobilizing the injured leg, surgery where the tear of the ligaments is severe or when the fracture is severe or by providing analgesic medication (Davidson, Wilson, Chalmers, Wilson, & McBride, 2009).