Lewis suffered the injury during England's RBS 6 Nations defeat against Wales at Twickenham on February 2.
His rehabilitation and treatment was undertaken by the England and Tigers medical teams and it was agreed that a further specialist consultation should take place.
Dr Hakan Alfredson, a world expert on tendon injuries, met Lewis and representatives of the England and Tigers medical teams in Sweden on Thursday, March 27 and it was decided that an operation was required, with the procedure taking place that afternoon.
“We’re very disappointed for Lewis,” said Tigers forwards coach Richard Cockerill. “He’s an important player for us so it’s obviously a blow for the club. We wish him well in his recovery and look forward to seeing him back in a Tigers shirt once he is ready to play again."
Those sentiments were echoed by England head coach Brian Ashton. "I'm bitterly disappointed for Lewis," said Ashton. "I hope the operation has been successful and that he is playing in his usual combative way as soon as possible."