After a fall, a 65-year-old woman complains of pain in her hip joint during movements and inability to rest her full weight on this limb. Objectively, the pain intensifies during palpation, the limb is rotated outwards and shortened. "Stuck heel sign" is positive - the patient is unable to raise her straight leg and hold it in this position, the heel slides on the floor when bending the leg. What is the most likely diagnosis in this case?