DePuy Synthes Sales Inc. had two problems when it asked a federal judge in the Southern District of Ohio to enforce an arbitration subpoena that commanded Smith + Nephew Inc., a non-party based in Massachusetts, to provide testimony and documents in Cincinnati.The first was venue. DePuy figured it picked the right forum, even though the subpoena’s caption said the proceedings were being administered by the “American Arbitration Association, Indianapolis, Indiana,” because the arbitrator practices law in …