$THE two main most common limb deformities on the front legs that are treated are known as valgus and varus. A foal that has valgus conformation in his front imbs is when the legs move away from the midline between the foals shoulders. This can often be referred to as ‘knock-kneed’ when it occurs through the knees. Varus conformation is the reverse, so when a foal has limbs that bow outwards from the midline. As the movement of limbs suggests, this can be know as ‘bow-legged.’ As you would expect, most of these angular deformities come via the fetlock and knee joints when there is imbalance growth in the plates. Often the conformation issues in newborn foals are rectified as the foal grows and strengthens or with careful management, either via farriery or restricted exercise. However there will be a certain number who might “need” corrective surgery. The primary types of correct surgery available are periosteal elevations (P.E.), or stripping, and transphyseal bridging. The first, periosteal stripping, is when a small strip of periosteum is removed from a slower growing side of the growth plate in order to stimulate growth, and therefore one side catches up with the other. The second type of surgery is transphyseal bridging (screw), where a metal screw is inserted across one side of the growth plate in order to slow down the growth on other side, again as with the P.E. to let both sides catch up. These screws must be removed once the foal’s legs are corrected. As a foal’s fetlock growth plate is nearly closed by the 90th day of age, it therefore means that if surgery is needed on that joint it needs to done in the early stages of their life. Before the advances in transphyseal bridging, many breeders were using periosteal stripping, having to make a decision at just 45 days of age and as a result it was often hard to determine, if surgery was performed, whether the corrections were due to time and natural strengthening, or the surgery. The transphyseal bridging technique now allows the decision made on a fetlock to be taken at around the 75-day stage, giving breeders a much better idea if surgery is really an option. By leaving surgery to just before the growth plates close (i.e. 75-100 days from birth), rectified limbs cannot revert back as they were. The growth plates in the knees close at a much later stage of a thoroughbred’s life, therefore these corrections can be done right up into their yearling year. So how correct does a racehorse need to be in order to sustain the pressures of training? The Equine Veterinary Journal published a paper in 2004 on the “role of conformation in musculoskeletal problems in the racing thoroughbred.” Professors Anderson, McIlwraith, and Douay concluded in their detailed findings that a horse with an “increase in the carpal angle as viewed from the front (carpal valgus) may serve as a protective mechanism, as the odds for a carpal angle fracture and carpal effusion decreased with an increase in the carpal angle.” James Tate, who is not only a vet but is also a trainer based in Newmarket, England, agrees very much with these findings and feels that only foals with extremely poor conformation require surgery on their limbs if they are to have any chance as a racehorse. Tate’s concern is that “somebody is left with the decision of exactly what angle the foal’s leg should be and this is a very difficult decision to make,” particularly when the decision is being made at such an early stage of it’s life. With this, Tate feels with many cases, “Where possible, I would prefer to let Mother Nature do the work with the help of good conservative management; for example, good trimming, appropriate exercise, appropriate nutrition, and turn-out in appropriate pastures.” However, from a commercial angle Tate says surgeries can help a yearling or foal gain a higher price at auction due to it having ‘straight legs,’ but would this necessarily be beneficial when it comes to it’s years as a racehorse? Tate adds that the period of post-surgery rest can also cause plenty of problems. “Excessive box rest or restrictive exercise after surgeries can cause a growth spurt once normal exercise is resumed, which can then cause more complications, for example, growth plate problems such as physitis or epiphysitis or the development of an osteochondrosis dissecans (OCD) cartilage lesion due to uneven growth.” Duncan Taylor, President of Taylor Made Farm and Sales Agency, feels that when a joint has severe deformities, a screw helps keep the horse sound on the track while the P.E. is mostly cosmetic. Mark Taylor, Taylor Made’s Vice President of Public Sales, goes on to say that over the last 15 years periosteal stripping has declined by 90%, but despite this they have seen many of their client’s horses win Grade 1 and Group 1's after having periosteal strips and transphyseal bridges. As far as risks of surgeries are concerned, Mark Taylor feels that “the primary risk for the horse is from secondary issues such as infection, bandage problems or being injured coming out of anaesthesia.” Corrective surgery has helped with soundness of some racehorses who had extreme limb deformities, says trainer Richard Mandella; it certainly has its place as an option. He goes on to say that over the years it has helped with some extreme cases where surgery was able to give racecourse opportunities to horses that would otherwise not stand being in training. But Mandella does go on to say that perhaps, at times, we overuse it in some cases. There are two issues to breeders in America, says international bloodstock agent James Delahooke. Do they want the thoroughbreds to score in the sale ring or on the racecourse? Delahooke feels that if a foal has been operated on with the aim of inflating its sale price then he suspects this could jeopardise its chances of staying sound on the racecourse. Surely forcing limbs in directions will put pressure on other limbs and joints. Delahooke feels that with a good stud manager the correct way to raise young stock is leaving it to develop via Mother Nature taking it course with the help of corrective trimming. “At the end of the day do you want a racehorse?” he asks. This is also the view taken by European sales consignor Jamie Railton, who pinhooks yearlings in the U.S. and Europe. Railton would also like to see Mother Nature take it course with foals with limb deformities. He says, “Surgeries are done for cosmetic reasons for the sale ring and not done to improve the racecourse performance.” He goes on to say, “I don’t think that there is any evidence to suggest that those that have had any surgery will be any sounder than those who have not.” However trainer Graham Motion says that he has had not had a problem with training horses under his care that may have had corrective surgery. They would have certainly not been trained any differently to horses that have not been operated on. Railton poses the final question: “Why is it done (corrective foal surgeries) so much more in the U.S. and not in Europe? Who is right, who is wrong?” Is there a right or wrong answer? Probably not, but perhaps the issue is corrective surgeries being carried out excessively in order to compete in a competitive commercial market. Although one could make a case of surgery for foals that have extreme limb deformities to perhaps give them a better chance of success on the racecourse, especially if some have managed win at top level. Or would they be just as sound if left to good management and Mother Nature?$

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