The knee is an amazing joint that allows for intense forces and movements. The joint consists of the thigh bone (femur), the shin bone (tibia), and the knee cap (patella). Knee problems can arise from structures within the joint or the structures around the joint. Problems can be from acute trauma or from chronic overuse.
Ligamentous Injuries
A ligament is a tough structure that connects two bones together. An injury to a ligament is called a sprain and can be a stretch, a partial tear or a complete tear. The four major ligaments of the knee are the medial collateral ligament, the lateral collateral ligament, the anterior cruciate ligament and the posterior cruciate ligament. Injuries to ligaments can occur after a trauma, sports, or even just an awkward landing. Ligament sprains result in pain, instability and swelling of the knee. Treatment is dependant upon the ligament sprained, but surgery is often required.
Overuse Injuries
Knee pain can develop due to too much activity. Conditions such as patellofemoral pain syndrome, iliotibial band friction syndrome, pes anserine bursitis and patellar tendonitis are the most common overuse injuries of the knee. They result from improper training programs or relative muscle weakness and imbalances. Physical therapy is the most important treatment, along with rest, ice, bracing, injections and medications.
Arthritic Conditions
Arthritis means inflammation of a joint and causes pain, swelling and stiffness. Osteoarthritis is the term used for wear and tear of the knee. This affects the articular cartilage of the knee (the shiny cartilage you see at the end of a chicken bone). Treatment for osteoarthritis involves activity modification, physical therapy, ice, bracing, corticosteroid injections, viscosupplementation and surgery. Symptoms of fever with a hot, swollen joint could be the sign of a more-serious knee problem.
Meniscal Injuries
The meniscus is a crescent-shaped structure that provides shock absorption and support to the knee. There are two menisci in the knee, a medial and lateral meniscus. They are located between the femur and tibia. With some injuries the meniscus can tear and even flip up-and-over within the knee, causing the knee to lock. Other meniscal tears are degenerative and can happen without a traumatic event. Symptoms of meniscal tears include pain, swelling and mechanical symptoms like locking or catching. Physical therapy, medications and injections may help, but surgery is often required to relieve symptoms.
References
- "DeLee and Drez's Orthorpaedic Sports Medicine, 3rd Edition," 2009
- "The Sports Medicine Resource Manual," 2008
