King Abdullah, Custodian of the Two Holy Mosques, underwent surgery to tighten the ligaments around his third vertebra, the Royal Court said in a statement. The surgery performed at King Abdulaziz Medical City here, Monday, was successful, the statement said. King Abdullah went into the hospital late Sunday for the operation. The Monarch had two rounds of back surgery in the United States last year after suffering a herniated disc, leading to a three-month recuperation period outside the Kingdom.