This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Ohopaedics Q Bank, Subject name: Orthopaedics
Triple deformity of knee is classically seen in: 
Select and explain. 
A. Fracture patella, B. Tuberculosis, C. Rheumatic ahritis, D. Ankylosing spondylitis
B: Tuberculosis
Answer: B: Tuberculosis 
Explanation: Triple deformity is seen in tuberculosis of knee consists of ( Mnemonic PErF ):- P- Posterior subluxation of tibia Er- External rotation of leg F- Flexion at knee