What are the three hallmarks of osteoarthritis seen on X-ray?

• A. Osteophytes, Subchondral Cysts, Joint space narrowing
• B. Osteophytes and Joint space narrowing only
• C. Subchondral sclerosis, Osteophytes, Soft tissue swelling
• D. Subchondral cysts, Joint space widening, Osteophytes

Answer: (A)

Osteoarthritis on X-ray shows degenerative changes in the joint that reflect cartilage loss and bone response. The three hallmarks here are osteophyte formation at the joint margins, joint-space narrowing from loss of articular cartilage, and subchondral cysts within the bone beneath the joint surface. Osteophytes form as the bone tries to repair itself from cartilage degeneration; joint-space narrowing indicates the thinning or loss of cartilage; subchondral cysts arise when synovial fluid penetrates tiny fissures in the subchondral bone, creating cystic spaces. While other findings like sclerosis can occur, this combination of osteophytes, joint-space narrowing, and subchondral cysts best captures the typical radiographic pattern of OA in many exams.