Mike Tyson has undergone knee surgery to repair the injury he suffered during his defeat to Englisman Danny Williams in Louisville, Kentucky.
Tyson motioned to his knee during the opening round, before succumbing to a fourth round knockout from the Brixton-born fighter.
"I'm shocked Mike was able to box for three more rounds," said Richard Emerson, who diagnosed the injury.
Tyson's manager Shelley Finkel added: "It explains a lot."
Finkel added: "Once he lost the ability to pivot, turn, or move laterally, much less put pressure on his left leg, he lost the ability to throw any more meaningful right hands which had been so effective up to the point of the injury."
Emerson also confirmed that Tyson would have found movement difficult. "Under normal circumstances the pain and locking that occurs with this injury would make it impossible for the athlete to continue," he said.
"He would have to be taken out of the game or the boxing match on a stretcher or with assistance."
Filed by Aidan O'Doherty
