Mr Ritchie, 52, a close friend of Richard Branson, has already undergone two major operations to fix a series of broken bones and repair damage to his abdomen and pelvis.
He saved the Virgin entrepreneur's life during another balloon trip last year, is being treated in London's Middlesex Hospital after he was flown home by air ambulance from the accident scene in Morocco.
He had been preparing for Mr Branson's latest bid to become the first to fly around the world by balloon.
A hospital spokesman said: "So far the surgery has gone well and Mr Ritchie remains stable."Reuse content