This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: FMGE 2017, Subject name: Orthopaedics
Herberden's ahropathy affects: 
Select and explain. 
A. Lumbar spine, B. Sacroiliac joint, C. Distal interphalangeal joint, D. Knee joint
C: Distal interphalangeal joint
Answer: C: Distal interphalangeal joint 
Explanation: Osteoahritis of DIP is known as Heberden's nodes. Osteoahritis of PIP is known as Bouchard's nodes Sacroiliac joint is affected in ankylosing spondylitis Knee joint is usually affected in osteoahritis &Pseudogout