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: Medicine
Least common site involved in osteoahritis is 
Select and explain. 
A. Hip joint, B. Knee joint, C. Carpometacarpal joint of thumb, D. Distal carpophalangeal joint
D: Distal carpophalangeal joint
Answer: D: Distal carpophalangeal joint 
Explanation: Ans. is 'd' i.e., Distal carpophalangeal joint In the hand the joints specifically involved are ? Distal interphalangeal join& (of paicular impoance is the point that this joint is not involved in rheumatoid ahritis). Proximal interphalangeal join& First carpometacarpal jointsQ Remember these two impoant features of joint involvement in osteoahritis It does not involve the metacarpophalangeal jointso It does not involve the wrist joINTEGER(2. It also does not involve the carpometacarpalQ joint (except at the base of thumb). Osteoahritis involves the carpometacarpal joint at the base of thumb, infact it is the second most common area of involvement in osteoahritis. Other joints which are commonly involved in osteoahritis are Hips, Knees, Lower lumbar Cervical. Joints which are usually spared in osteoahritis are WristsQ, carpometacarpale ElbowsQ Shoulder joint