2) Congenital problems in the limb
Congenital problems of the limb can trigger knee osteoarthritis by producing a misalignment of the anatomical portions of the lower limb, which creates friction between bone ends and may increase the wear and tear in the cartilage.
This is a problem that worsens over time, and when it is triggered by a congenital problem, osteoarthritis may show up as a problem from a very early stage in life. This is why these patients develop osteoarthritis from early childhood, and many of them require surgical repair to maintain their joint function.