This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Injuries Around Arm & Elbow, Subject name: Orthopaedics
Most commonly affected joint in myositis ossificans is 
Select and explain. 
A. Ankle, B. Knee, C. Hip, D. Elbow
D: Elbow
Answer: D: Elbow 
Explanation: Ans. d (Elbow). (Ref. Maheshwari, Orthopaedics, 2nd ed., 42)Myositis ossificans# It is ossification of haematoma around a joint resulting in the formation of a mass of bone restricting joint movements often completely.# It is due to severe injury to a joint especially when the capsule & the periosteum have been stripped from the bones by violent displacement of the fragments.# It is particularly common around elbow joint in children as periosteum is loosely attached to bones also in the patient with prolonged or permanent neuronal damage from head injury & in paraplegia.# Massage following trauma is a factor known to aggravate myositis ossificans.# The most commonly affected joint in myositis ossificans is elbow.# The calcification classically starts from periphery in myositis ossificans, while from center in parosteal osteosarcoma.