MADRID (AP) — Spain's King Juan Carlos has been admitted to a Madrid hospital to undergo an operation on a suspected infection of the hip that makes it difficult for him to walk.

The 75-year-old king rolled down the window of his car to greet waiting journalists as he drove up to the private Quiron hospital Tuesday afternoon.

The king was working hours before entering the hospital, meeting with 16 new ambassadors to Spain.

He is to be operated on later Tuesday by Miguel Cabanela, a specialist surgeon who flew in from the Mayo Clinic in Rochester, Minnesota,

It will be the king's third hip operation in less than two years.

The monarch's once unquestioned popularity has dipped in recent years following scandals that have tarnished the royal family's image.

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