Philippon is the same doctor who performed similar surgery on Yankees third baseman Alex Rodriguez earlier this year.
MacDougal should begin a throwing program in six to eight weeks and should be fully recovered by Spring Training.
MacDougal had problems with his hip since late August, but pitched until the end of the season. In 52 games for the Nationals, MacDougal had 20 saves and a 3.60 ERA.
Bill Ladson is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.