This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Rheumatoid Arthritis, Subject name: Orthopaedics
Joint involved in rheumatoid arthritis are all EXCEPT: 
Select and explain. 
A. PIP, B. DIP, C. MCP, D. Cervical spine
B: DIP
Answer: B: DIP 
Explanation: ANSWER: (B) DIPREF: Apley's 8th e p. 51-58Commonly involved joints in RA:WristMCPPIPElbow7KneeAnkleMTPLess commonly involved joints:Upper cervical spine with atlanto axial subluxationHip jointTM jointSubtalar and foot jointsJoints not involved in RA:Lumbar spineDIP