Dinah came home last night. She had been given a series of tests including a bone scan and an MRI, and the conclusion was a probable bone infarct. According to Wikipedia, that is "tissue death caused by an obstruction of the tissue's blood supply, which leads to a local lack of oxygen. The resulting lesion is referred to as an infarct", so a small section of her femur, near the base of the implant, and near the bottom of the fracture from a few weeks ago, may have died. The treatment is to stay off the leg, and observe it over time. Ominously, Dr. Bean said, "I don't think we need to replace this hip just yet".
We are hoping that Dinah will heal herself and that no further surgery will be needed.