Kieren Fallon could miss the rest of the season after undergoing five hours of surgery to repair nerves in the shoulder he damaged in a fall at Royal Ascot on Wednesday.

The champion jockey also had ligaments, that were crushed in the four-horse pile-up, realigned during the operation at the National Orthopaedic Hospital in Stanmore, Middlesex.

"Kieren's operation was very complicated, but thankfully all the feeling has returned to his arm and he can move his hand quite freely," his wife Julie told the Racing Post.

"He remains in considerable pain and, although, his shoulder is not in a sling, it's very heavily strapped.

"His surgeon has been unable to give him a clear idea as to how long he will be away from the racecourse, which is the obvious question that Kieren will be asking. It could well be some months, but it's impossible to say at this stage whether he'll be back before the end of the season.

"The surgeon has told Kieren that he must be patient and let the damage repair itself, which may take some time."

Fallon has been champion jockey for the last three seasons. He is on the 59-mark this term.