Broncos running back Knowshon Moreno has had arthroscopic surgery on his right knee since the end of the season. Broncos coach John Fox confirmed the surgery when asked Thursday morning at the NFL’s scouting combine. Moreno underwent a treatment to insert stem cells harvested from bone marrow in his pelvis into his right knee. It is the same knee Moreno tore the anterior cruciate ligament (ACL) to end his 2011 season. Moreno is currently rehabbing at the Broncos’ Dove Valley complex. The running back, who just finished his fourth year with the team, left the Broncos’ playoff loss to the Ravens with a knee injury.