10 January 2011
Classified as a hinge joint, the knee is made up of two main bones that meet to make up the hinge, the femur and tibia. Protected by the patella, otherwise known as the knee cap, this joint gains its support, flexibility, and range of motion from its supporting tendons and ligaments. The knee is the largest joint in the body and while it may seem simple, it is actually one of the most complex joints in the body. Additionally, the knee is the most common injury reported during exercise and among professional athletes.
There are four main ligaments that are responsible for the connection of the knee – the anterior cruciate ligament, known as the ACL, the posterior cruciate ligament, known as the PCL, the medial collateral ligament, known as the MCL, and the lateral collateral ligament, known as the LCL. The ACL and PCL, if injured, often are unable to heal without surgical intervention, due to a low blood supply. Another oft-injured part of the knee is the meniscus, or the plural menisci. The menisci are two pieces of cartilage in the knee that works to distribute the weight of the body across the knee joint. Shaped like two half moons, the menisci are susceptible to injury, especially to athletes both professional and recreational. If the knee is twisted and force is applied, the menisci can tear.
There are also muscles supporting and surrounding the knee. These include the quadriceps and the hamstrings. A group of four distinct muscles, the quadriceps or quads form the quadriceps tendon, which works to connect this muscle group to the knee cap, or patella. This connection is what allows the knee to extend, or raise directly in front of a person. The hamstrings work to aid in the flexion of the joint, as well as provide additional support and stability.
Arthritis of the knee can also occur over time. Due to contributing factors including age, weight and mechanical wear and tear, arthritis of the knee affects millions of Americans. Pain from arthritis can be treated conservatively with medications, injections and physical therapy, but advanced cases may require a full knee replacement.
Depending on the injury and severity, the knee can be treated with a variety of methods. Conservative treatments can start with the use of non-steroidal anti-inflammatory medications (NSAIDs) such as ibuprofen and aspirin. Hot and cold compresses can also be applied depending on whether the injury is inflammatory or involves deep muscle pain and/or spasms. Physical therapy and acupuncture also can be included as conservative treatments for injuries of less severity. Joint injections are minimally invasive and can be highly effective. Consisting of a corticosteroid injection administered directly into the joint, this method can reduce inflammation and decrease pain caused by the injury.
In severe cases, surgery may be advisable. If a meniscus tear is the cause of pain and debilitation, laparoscopic surgery may be an option. Consisting of surgery done through a small incision and using a scope, this surgery is preferred over full open knee surgery because it is less invasive and involves a shorter recovery and rehabilitation period. Full knee replacements may be warranted due to either degeneration due to arthritis, or severe injury.
References:
http://www.medicalook.com/human_anatomy/organs/Muscles_involved_in_knee_motion.html
http://www.sportsinjuryclinic.net/cybertherapist/kneeanatomy.php
