Medical Properties Trust must limit its cash dividends while a key tenant remains in bankruptcy.Medical Properties Trust (MPW 4.36%) has offered a double-digit dividend yield for over a year. That big yield was a sign that the market didn't believe the real estate investment trust (REIT) would be able to maintain its dividend level, even after cutting it by nearly 50% last August. The market's skepticism proved to be correct. The healthcare REIT is indeed reducing its dividend again. The cut, which could pr ...