In 2010, there were roughly 10.4 million patient visits to doctors’ offices because of common knee injuries such as fractures, dislocations, sprains, and ligament tears. Knee injury is one of the most common reasons people see their doctors.
Your knee is a complex joint with many components, making it vulnerable to a variety of injuries. Many knee injuries can be successfully treated with simple measures, such as bracing and rehabilitation exercises. Other injuries may require surgery to correct.
Check out this site for more information:
http://orthoinfo.aaos.org/topic.cfm?topic=A00325
