"I'm obviously very disappointed to have to end my playing career. I hoped to continue playing for a few more years and was determined to force my way back into the England set up having been injured in our last warm up game before the Rugby World Cup in 2011, but it wasn't to be.
"It's been an horrible 15 months barely being able to play for Sale and I tried so hard to come back. Even after the first two failed operations I hoped to return playing, but after the third operation I reluctantly had to accept medical advice that I should stop.
"My biggest regret will be that I never had time to repay the faith Sale Sharks and their supporters put in me when they signed me and I would like to thank them for the support they have shown and the way the fans stood by me. I was desperate to produce some really good performances to show them what I was capable of but unfortunately that's how life goes sometimes and as they say, when one door closes another one opens. I look forward to getting stuck in to whatever new challenges arise and working hard at them like I did in rugby."
Sharks' team mate and RPA Player Representative Sam Tuitupou said: "All the boys at Sale are really disappointed for Hendre. It hits you hard as a squad when you lose a mate as well as a great player, particularly having already seen so many other top players being forced to retire this season. It's a reminder of how fragile your career can be.
"Hendre is such an upbeat character, one of the nicest guys you could meet who always has a smile on his face and he will be missed by everyone in the squad."
RPA Rugby Director, David Barnes, commented: "It is a great shame to lose Hendre from the game earlier than he would have wished. When he was at Leeds Carnegie in 2010 Neil Back rated him as the best open-side flanker in the Premiership and had high hopes for him at international level. Hendre worked incredibly hard in an attempt to come back from the injury, but unfortunately medical advice has indicated it will not be possible for him to play professional rugby again.
"Hendre has been working closely with our RPA Player Development Manager at Sale Sharks, Tim Nicholls, exploring possible options open to him as he looks to build a new career. We all wish him and his family the very best as he makes the transition."