The microfracture surgery on the 7-foot Oden's left knee was the fifth surgery he has undergone since being chosen first by the Blazers in the 2007 NBA Draft. Oden hasn't played since the 2009-10 season.
Acting Trail Blazers General Manager Chad Buchanan said doctors were initially just looking to perform a procedure to clean the joint of debris.
"However, once the doctors were inside Greg's left knee, they unfortunately found articular surface damage and determined microfracture (surgery) was necessary," he said.
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