I come across many patients with knee pain. Some have a minor cause treatable in few days by mild painkillers, while others have a major abnormality needing operation. Our knee joint is a complex part of the body with many tissues inside like cartilage, ligament, meniscus, synovial fluid, etc. Let us have a brief look at some of these:

Cartilage: This is a cushion between the bones of knee which needs continuous repair to function properly.

Ligaments: There are many ligaments in the knee. Their tear cause painful and loose knee.

Meniscus: They too are cushions of knee, softer than cartilage. Their tear cause painful knee.

Synovial fluid: This is a lubricant in the knee preventing friction between bones.

As we can see there are many components in the knee which are important in normal functioning of knee. 

Now let me clear some misconceptions regarding knee:

A normal knee X ray does not guarantee a normal knee.

An abnormality in knee on MRI does not mean your knee needs surgery.

Removal of knee fluid for diagnosis or therapy does not affect knee function.

Fall while running or pain after jumping can cause serious knee ligament or meniscus tears.

"Partial", "Grade 1" "sprain" words in MRI report mostly never need operation.

Exercises make muscles around knee strong and protect it from ageing early.

Medicines claiming cartilage repair ability are still in experimental stage.