Former President George W. Bush had knee surgery over the weekend. 

The partial knee replacement took place in Chicago on Saturday, and Bush is back in his hometown of Dallas recovering "quickly," his spokesman Freddy Ford confirmed. 

The outpatient surgery took place at Midwest Orthopaedics at Rush University Medical Center, according to NBC, which first reported the news. Bush, 67, has remained active since leaving the White House and is known for his fitness.

Earlier this month, he hosted a 100K, three-day bike ride at his ranch to honor injured military from Iraq and Afghanistan. 

Last year, he underwent surgery to have a heart stent implanted to open up a blocked artery.