The serious injury suffered by Gingernuts as he cantered to the barriers at Flemington last Saturday may have been due to an accumulation of damage to his pastern, according to the man in charge of the horse's emergency surgery earlier this week.
Dr Chris Whitton is the head of equine medicine and surgery at the University of Melbourne Veterinary Hospital at Werribee and said on Thursday that his research has led him to believe the injury to Gingernuts could have been building over time.
"It's very difficult in an individual case to say exactly what caused it, but in general, these types of injuries are due to an accumulation of damage over time with high-speed galloping exercise," Dr Whitton told Racing.com.
"So when it happens is not that relevant, it's more what has happened in the weeks and months coming up to that."
It has been three days since Gingernuts underwent emergency surgery to repair a fractured pastern and while the New Zealand star is far from out of the woods, the early signs are encouraging, Whitton said.
"Generally if you can get the pieces back together well and get a stable fixation - provided you don't get complications of infections and those sort of things - then generally they go alright," he said. "But there's a long recovery time.
"With most of these things, we would give them six months to allow adequate bone healing before we thought the horse was able to start taking more normal loads on the limb."
Gingernuts was rushed to the Werribee clinic last Saturday night after breaking down when simply cantering on his way to the barriers for the A$2 million Emirates Stakes at Flemington.
Whitton is currently involved in a program aimed at identifying the reasons behind lower-limb injuries in racing thoroughbreds. The program is funded jointly by the State Government, Racing Victoria and the University of Melbourne and Whitton said his team had already identified useful information.
"It's obviously a complex issue but it's rarely that they take one bad step, although that can happen, but it's more commonly an accumulation of damage over time," he said.
"These injuries are devastating for everybody and it's really important for us to understand why they occur and what we can do to minimalise the risk.
"There is always going to be some risk but we can do a lot to limit the risk particularly as we know that these are coming over time.
"If we can understand that better and understand what causes that, perhaps there's ways that we can minimalise the risk.
"There's already things that we've learned from our research that has helped but we've got a lot more work to do to understand it and provides trainers and owners with the right advice on how to prevent them."
Whitton said his team had prepared quickly for the arrival of Gingernuts last Saturday once he had been contacted by the vets at Flemington.
"We had a team of people ready to accept the horse and the first thing is to get them off the float safely and to get an x-ray to determine exactly what the damage is," he said.
"Obviously the vets at Flemington - the Racing Victoria vets - were concerned that there was something seriously wrong and we need to assess it to work out what the plan is going forward.
"Once we had the x-ray, it was clear the horse had fractured its pastern and then it was a matter of planning a way forward as to how we were going to plan that."
It was decided that the horse needed immediate surgery.
"On Monday the horse underwent a general anaesthetic and then we did a CT scan which allows us to get a three-dimensional view of the bone and understand the complexity of the fracture and plan exactly where we are going to put the screws so we can get the maximum compression across the fracture line," Whitton said.
"He then got transferred to the surgery and the screws were placed and we tend to do that under fluoroscopic guidance so we can actually see in real time the screws going into the position they need to be in.
"We also had to scope the joint to assess the joint surface to make sure that it was OK and to remove some fragments inside the fetlock joint and then the horse got a cast put on and then was put in the recovery box to recovery and things have gone OK.
"We're happy with how things have gone so far but there is a long way to go.
"Dealing with horses, there are lots of things that can go wrong. It's a day-to-day proposition at the moment but we're happy with how things are going. Everything has happened as we would expect but there is still a long way to go.
"We just hope that he remains relatively sound on the limb and comfortable and then it's a matter of waiting for the healing process to take place.
"We are going to keep it bandaged and keep him confined so he's putting as little a load on the bone as possible for the moment.
"We are just waiting to make sure everything goes smoothly and the wound heals up and we don't get infection and all those other complications that can sometimes be a problem." racing.com