In stage 2, diagnostic images or X-rays of knee joints will show more bone spur growth. People being experiencing joint pain. Typically, the area around the knee joint feels stiff and uncomfortable, particularly when sitting for an extended period, after rising in the morning, or after a workout. Joint-spacing is narrowing. The cartilage begins breaking down.

In stage 3, there is obvious erosion to the cartilage surface between bones and fibrillation narrows the gap between the bones. There are proteins and collagen fragments released into the synovial fluid as the disease progresses, wherein the bones develop spurs at the joints as it becomes rougher.

With the progression, there is obvious joint inflammation which cause frequent pain when walking, running, squatting, extending or kneeling. Along with joint stiffness after sitting for long or when waking up in the morning, there may be popping or snapping sounds when walking.

In stage 4, the joint space between the bones is considerably reduced, causing the cartilage to wear off, leaving the joint stiff. The breakdown of cartilage leads to a chronic inflammatory response, with decreased synovial fluid that causes friction, greater pain and discomfort when walking or moving the joint. The advanced stage of the disease shows development of more spurs causing excruciating pain, which makes even everyday activities, including walking and descending stairs a challenge.