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Knee diagram
Arthritis
Overuse
Acute Knee Injuries
Knee Joint Injuries:
- Anterior cruciate ligament (ACL) injury
- Lateral collateral ligament (LCL) injury
- Medial collateral ligament (MCL) injury
- Posterior cruciate ligament (PCL) injury
Anterior (Front) Injuries:
- Chondromalacia patellae
- Jumpers knee (patella tendonitis)
- Osgood Schlatters disease
- Runners knee (patellofemoral pain syndrome)
Medial (Inside) Injuries
- Medial cartilage meniscus injury
- Medial ligament sprain
- Osteoarthritis of the knee
- Synovial plica/patella plica
Lateral (Outside) Pain
Posterior (Back) Pain
Acute Pain
Arthritis of the knee is one of the more common causes of knee pain. Three basic types of arthritis commonly affect the knee and cause pain. Osteoarthritis is the most common form of knee arthritis. This form of arthritis involves degeneration of the all-important cartilage, and the risk of developing the disease increases with age. Rheumatoid arthritis is an inflammatory type of arthritis that can destroy the joint cartilage, and it generally affects both knees. Post-traumatic arthritis can develop after experiencing an injury to the knee. This type of arthritis is similar to osteoarthritis and may occur years after a fracture, meniscus tear, or ligament injury. More on arthritis, knee pain and joint pain relief.
Overuse is also a common cause of knee pain, and can include muscle strains, tendonitis, and bursitis. In the beginning, the knee pain is often mild and intermittent, but if you continue the overuse-cycling, kneeling, heavy lifting or climbing-where small stresses are repeated many times without allowing enough time for recovery in between, then the pain worsens over time. When the muscles and tendons become overly stressed, microscopic tears develop, and inflammation often sets in. If the tears are allowed to heal before you subject them to more overuse, then you have a good chance of relieving your pain.
Acute knee injuries, such as torn ligaments and torn cartilage, frequently occur during sports activities that involve turning, running, jumping, and sudden stops, or contact sports such as football and wrestling. The anterior cruciate ligament (ACL) is one of four major knee ligaments and also one that is often the target of injury. Because the ACL is critical to knee stability, people who have an ACL injury often say that their knee has “given out” from under them. An overuse injury can be considered to be acute if it causes pain or inflammation. Acute knee injuries can also happen if you haven’t exercised for a long time and you suddenly engage in running, jumping, or other weight-bearing activities that put a lot of stress on your knees. Another source of knee injuries? Automobile accidents, in which about one-third of injuries involve the knee.


