There are several large groups of knee problems that can cause pain with everyday activity or with more vigorous exercise. They include:

The most common knee injury that cause younger patients to seek surgical treatment is a torn meniscus. The medial meniscus (on the inside of your knee) is more commonly injured than the lateral (on the outside of your knee) meniscus. Common symptoms of a torn meniscus include intermittent or constant inability to straighten out your knee completely or aching and swelling during and after athletic activity. Failure to get a torn meniscus treated may lead to significant injury to the cartilage covering of the two major bones forming the knee joint (e.g. – the thigh bone-femur and the shin bone-tibia).

One increasingly common injury to the knee is the ACL (anterior cruciate ligament) tear. The ACL is the tough ligament that connects the back of the femur to the front of the tibia. Some expert feel ACL tears are on the rise because kids are playing demanding sports such as soccer, basketball and volleyball. Another common cause on ACL injury is skiing accidents. 

So how do you avoid an ACL tear? Experts say decrease the stress on the knee. Athletes are encouraged to make soft, silent landings, with toe-to-mid foot rocking. Keep the knees flexed and don't let them bow in or out. Keep the chest over the knees. Strengthening specific thigh muscle groups may offer significant protection against ACL injury. 

If you ski, then be sure to have up-to-date bindings that release in multiple directions. Bindings should be backed off to minimum tension at the end of each season, adjusted by a professional regularly, and kept properly lubricated. Do not tighten your bindings release settings beyond your skill and strength level! 

Knee pain due to degenerative joint disease or osteoarthritis occurs through the wear and tear of everyday use over a period of years. It can be accelerated by a prior injury to the knee cartilage, an untreated knee injury such as a torn meniscus, and by being chronically overweight. If the cartilage covering the bones in the knee is injured, it unfortunately heals very poorly compared to an injury to say your skin. It is important to minimize current and preventable causes of cartilage injury since modern medicine has few workable solutions for severe degenerative arthritis short of joint replacement. 

There are a group of medical diseases that can also cause arthritis. They include problems as diverse as gout, lupus, Lyme disease, and psoriasis. 

Chrondromalacia is a common cause of anterior knee pain with activities such as walking, running, or climbing stairs. It often is not preceded by an injury and most commonly occurs in younger women. Avoidance of excessive knee stresses with the knee flexed and strengthening the thigh muscle groups often provides relief without surgery.