The knee is the largest joint in the body, and one of the most easily injured. It is made up of the lower end of the thighbone (femur), which rotates on the upper end of the shinbone (tibia), and the knee cap (patella), which slides in a groove on the end of the femur. The knee also contains large ligaments, which help control motion by connecting bones and by bracing the joint against abnormal types of motion. Another important structure, the meniscus, is a wedge of soft cartilage between the femur and tibia that serves to cushion the knee and helps it absorb shock during motion.

The most important advice is to seek treatment as soon as possible, especially if you:

• Hear a popping noise and feel your knee give out at the time of injury
• Have severe pain
• Cannot move the knee
• Begin limping
• Have swelling at the injury site

If you answered "yes" to any one of these questions, you should consult an orthopaedic surgeon for help in determining the severity of the problem. 

Visit our video library below to learn more about knee conditions, injuries, and procedures.