MADRID - Spain's Royal Palace says King Juan Carlos will undergo surgery on his right knee for injuries troubling him from sports activity in the past.

The palace said Tuesday the 73-year-old king, a keen sailor and skier, will undergo an arthroplasty operation during the first two weeks of June.

It said the king suffered pain in his knee that is making his normal physical activities difficult.

Arthroplasty surgery aims to relieve pain and restore motion by adjusting or rebuilding joints.

The palace said the king would maintain his agenda until the operation.

The monarch had a benign tumor removed from his right lung in May 2010.