Bone spurs in the knee are outgrowths of bone that develop in joints when there is increased pressure between bones from a lack of cartilage. Bone spurs are also called osteophytes. Bone spurs (or “spurring bone”) in the knee can cause pain and limit joint mobility, which can cause trouble with doing everyday activities like walking, squatting, bending, and going up and down stairs.
Source: Verywell Health