SHANGHAI – China's star hurdler Liu Xiang has successfully undergone surgery in a US hospital on the foot injury that forced him out of the Beijing Olympics, state media reported Monday.

The nearly three-hour operation took place Friday at the Memorial Hermann-Texas Medical Centre in Houston, Texas, according to reports posted on the official website of Chinese Athletic Association.

"We felt he did very well though the surgery," surgeon Tom Clanton, who has also treated Houston Rockets centre Yao Ming, was quoted as saying in the English-language China Daily.

"His prognosis for running in the future is quite good."

Clanton said Liu was expected to fully recover after four calcium deposits were successfully removed from his right Achilles tendon.

Liu's coach Sun Haiping said the 25-year-old former world champion will be on crutches for a few weeks during the observation and recuperation periods.

"After the surgery Liu will need a couple of months in the United States to recover while a full recovery will take half a year," Sun said in a report posted on the Chinese Athletic Association's site.

Liu was a strong favourite to defend his Olympic gold medal in the 110m hurdles at the August Beijing Games, but he dramatically pulled out after limping through the start of his first heat.