You slipped on a broken marble tread in your Hamilton Heights walk-up and shattered your hip. A surgeon at a Manhattan hospital rebuilt it with plates and screws, and two years and dozens of follow-up visits later, that same surgeon performed a total hip replacement because the joint never healed right. Then the building owner's insurance company sends you to its own doctor, who examines you for 15 minutes and writes a report saying you've fully recovered. This is where treat