otal hip replacement surgeries, in which worn and damaged portions of bone and cartilage are removed and replaced with an artificial joint. Existing hip replacement systems use different combinations of metal, ceramic and a form of plastic called polyethylene. The newly approved system is the first to combine a ceramic ball and a metal socket. As a condition of the approval, DePuy will conduct a postmarket study, monitoring patients for adverse events and metal ion concentrations in their blood, the FDA said. In April, J&J reported its Depuy business saw U.S. hip and knee sales decline 6% from a year earlier in the fir for the past week has been on an overseas diplomatic trip. The two are currently en route home. Top Democrats are trying to make the choice as obvious as possible.  "I can tell you that if it was me, I would resign," President Obama said in an interview with NBC.  On the other side of the aisle, House Speaker John Boehner, R-Ohio, also said Tuesday that Weiner should resign.  The House Democratic Caucus met Tuesday morning on Capitol Hill. Rep. Rob Andrews, D-N.J., said afterward that discussion of Weiner took up just 5 percent of the meeting, and that members did not discuss potential punishment for the congressman. But House Democratic Leader Nancy Pelosi made clear that Weiner's colleagues have a message for him.  "I hope that the, president having spoken and some leaders in Congress speaking out, that Congressman Weiner will hear this and know that it's in his best interest for him to leave Congress," Pelosi told reporters Monday.  She also noted that "not anybody here has the power to force somebody out of office."  Referencing one bit of leverage the leadership has, Pelosi said Weiner certainly wouldn't be offered any plum committee assignments if he were to stay -- but she urged him to make the decision himself to leave.  "This is beyond committee assignments. This is, we are asking to leave," she said.  Obama questioned whether Weiner can still do his job with the scandal hanging over his head.  "When you get to the point where, because of various personal distractions, you can't serve as effectiv