http://www.independent.co.uk/sport/football/premier-league/newcastle-write-off-injured-hatem-ben-arfa-for-rest-of-season-8537070.html
Sounds like the decision is being made by our medical team in discussions with the French lot too - in hindsight might have been better to do the operation back in December, but then I've no idea if that has other associated risks so I'm basically just guessing like everyone else!