This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Arthritis, Subject name: Orthopaedics
Feature of osteoarthritis is - 
Select and explain. 
A. Heberden node, B. Increased ESR, C. Onycholysi, D. Z deformity
A: Heberden node
Answer: A: Heberden node 
Explanation: Ans. is 'a' i.e.. Heberden nodeJoint involvement in QAo Common joints : Knee, Hip, Spine (cervical, lumbosacral), Hand (PIP, DIP, first carpometacarpal), first tarsometatarsal.o Uncommon joint: Shouldero Spared : Wrist, elbow, ankle, metacarpophalangeal.o In osteoarthritis of hand :Distal interphalangeal joint Heberden's node.Proximal interphalangeal jointBouchard's node