Former President George H. W. Bush broke a bone in his neck in a fall at his home in Kennebunkport on Wednesday, his official spokesman said. Mr. Bush, the 41st president, was in stable condition, but he will have to wear a neck brace, the spokesman, Jim McGrath, said on Twitter. The former commander-in-chief has a form of Parkinson’s disease and uses a wheelchair. In December, he was hospitalized in Houston for treatment of shortness of breath. He turned 91 last month and is the oldest living former president.