This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Surgery
Feature of osteoahritis is - 
Select and explain. 
A. Heberden node, B. Increased ESR, C. Onycholysis, D. Z deformity
A: Heberden node
Answer: A: Heberden node 
Explanation: Ans. is 'a' i.e., Heberden node Joint involvement in OA Common joints : Knee, Hip, Spine (cervical, lumbosacral), Hand (PIP, DIP, first carpometacarpal), first tarsometatarsal. Uncommon joint : Shoulder Spared : Wrist, elbow, ankle, metacarpophalangeal. In osteoahritis of hand : Distal interphalangeal joint :- Heberden's node. Proximal interphalangeal joint :- Bouchard's node