OA vs RA

• OA is a disease of over-growth → Bony Nodules
• RA is a disease of reduction → Erosion

OA Findings

Osteophytes (bony spur)

Subcondral sclerosis

• A thickening of bone below the cartilaginous articulation surface

Subconhdral cysts

• fluid-filled cavities within the bone that are under the cartilage

Loss of joint space

• Asymmebtrical narrowing is more consistent with OA