This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Spinal Injuries, Subject name: Orthopaedics
Block vertebrae are seen in - 
Select and explain. 
A. Pagets disease, B. Leukemia, C. TB, D. Klippel - Feil syndrome
D: Klippel - Feil syndrome
Answer: D: Klippel - Feil syndrome 
Explanation: Ans. is 'd' i.e., Klippel - Feil syndrome o A block vertebra is a type of vertebral anomaly where there is a failure of separation of two or more adjacent vertebral bodieso Associations1. There is a frequent association with hemivertebrae / absent vertebra above or below block level, posterior element fusion2. Fusion of multiple cervical vertebral bodies is also seen in Klippel-Feil syndrome and VACTREL anamoly.