With a bowed leg, excessive external forces are concentrated on the medial or lateral side of the knee, and even minor damage can lead to arthritis, which wears away the joint cartilage, causing joint pain and deformity.
If the outer cartilage of the knee wears down, the leg shape can be deformed into an X-shape, and if the inner cartilage wears down, an O-shape. If only have arthritis in one knee instead of both, it may develop a D-shaped leg, where one leg is straight and the other curves outward.
This can be both aesthetically unpleasant and cause problems with walking, so it's important to seek treatment in a timely manner.
