Multiple Choice Questions

Question 101. You are asked to see a patient on the ward, day 2 after a right total hip replacement (THR). He has Parkinson's disease and had been slow to get out of bed after the operation. Whilst climbing off a commode he suddenly complained of pain in the right groin and was unable to weightbear. The nurses hoisted him into bed and noticed that the right leg was externally rotated and shorter than the left. The most likely cause of his pain is: