The procedures on the 26-year-old shooting guard were successful, Blazers General Manager Rich Cho said.
"We're hopeful today's procedure will help alleviate some of the pain Brandon has been experiencing in his knees and allow him to get back to playing basketball again," Cho said.
No timetable was given for Roy's return. He averaged 16.6 points, 3.0 rebounds and 3.3 assists per game in 23 contests this season before his injuries.
Named the 2007 NBA Rookie of the Year, the three-time all-star missed time last season with a torn meniscus in his right knee.