This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Pelvis and Hip injuries, Subject name: Orthopaedics
[{'content': 'Posterior dislocation of hip is characterized by DELETE \nSelect and explain. \nA. Marked shoening of limb, B. Lengthening of limb, C. No change in limb length, D. Extension deformity', 'role': 'user'}, {'content': 'Answer: A \nExplanation: In posterior dislocation, if hip there is history of trauma & patient has a flexion, adduction & medial rotation deformity of the affected limb.There is marked shoening & gross restriction of movements of the hip Head of the femur is felt as a hard mass in the gluteal region & it moves along with the femur. There could be features of sciatic nerve palsy. *it is difficult to feel the femoral pulse ( vascular sign of Narath is negative) Ref: Textbook of Ohopaedics, John Ebenezer, 5th edition, page no 214', 'role': 'assistant'}]