Do I have a case for malpractice?

My wife fell down on the floor of our home on 4/4/11. She was transported to a local hospital via ambulance as she was complaining of severe pain to her left hip. She was examined by the doctors in the emergency room and X-rays were taken. The x-rays were examined by doctors and found to be negative for fracture and my wife was sent home. She was in a lot of discomfort and pain at home trying to walk with the aid of her walker & getting to the bathroom, etc. Finally on 4/7/11 she could not walk. She wanted go back to the hosptial. I called the ambulance and they took her to the emergency room again at this time they examined her and took X-rays of her hip and pelvis and did find a fracture of her left hip. One of the doctors looking the X-rays said to me that she did not understand why on 4/4/11 the X-rays were negiative for fracture and today 11/7/11 the X-rays should a fracture of the left hip. Two EMT''s told me that they thought her hip was fracture on 4/4/11shouldhave beenhosptli