Portland Trail Blazers centre Greg Oden underwent micro-fracture surgery on his left knee and will miss the remainder of the National Basketball Association season, the team said on Monday.
Dr. Richard Steadman, who has worked on the knees of numerous Olympic skiers, performed the surgery at his Vail, Colorado, clinic.
It is another setback for Oden, the number one overall pick in the 2007 draft, who has been plagued by knee problems throughout his career and has not played a game since 2009.
"This is not the news we were hoping for Greg or the organization," said Trail Blazers president Larry Miller. "It's hard to put into words the heartbreak for everyone involved but especially for Greg.
"He's a young man who has experienced a great number of physical challenges in his playing career and today is yet another significant setback for him."
Since being drafted, Oden has played in just 82 games (60 starts), averaging 9.4 points and 7.3 rebounds a game.