When New Edition performed in Boston a few weeks ago, it was clear Bobby Brown had lost a step. The Roxbury-bred Brown is 45, after all, and more than a few pounds heavier than in his heyday. But Brown has apparently decided that performing is too much work. TMZ reports that Whitney Houston’s ex-husband has left the New Edition tour after undergoing an “intrusive medical procedure.” The announcement came just days after Brown was seen laboring to keep up with his bandmates at a show in Mississippi. “I apologize to the fans of New Edition,” the singer said in a statement. “I really wanted to be with my brothers, but presently I am unable to give the fans what they typically expect from New Edition.”Names can be reached at firstname.lastname@example.org. Follow Mark Shanahan on Twitter @MarkAShanahan. Follow Meredith Goldstein on Twitter @MeredithGoldste.