Fractures – Types, Causes and Prevention
Racing and even training puts a vast amount of strain on the bones in the legs of horses. To understand the pressure that a leg is under during a full gallop, it is vital to point out that even though horses are much larger than human athletes, their bone structures are approximately the same size. When a thoroughbred is at full gallop, only one leg is in contact with the ground at a time. This causes the force of an estimated seven tons to be exerted on each leg as the horse moves through the stride. It is this force that can cause serious damage if a horse steps wrongly or is running on uneven ground.
Bone fractures in racing horses take on different forms and severity. While some fractures can be repaired through rest and care, some can end racing careers, while others lead to horses being euthanized. An open or closed fracture is easily distinguished as an open fracture protrudes through the skin, while a closed fracture is concealed under the skin. Complete fractures cause the bone to break into either two or more pieces, whereas incomplete fractures do not break the bone straight through. A displaced fracture indicates that the broken bone pieces are apart from one another, while nondisplaced fractures are hard to diagnose, as these are usually hairline fractures that are not easily detected on an x-ray. When a bone is broken into only two pieces it is referred to as a simple fracture and if the bone has broken into numerous pieces it is called a comminuted fracture.
There are a few fractures that are very common in racing horses. When it comes to knee fractures (Knees are made up of two rows of carpal bones that have an oval bone behind them, known as the accessory carpel bone. On the one side of the knee is the cannon bones’ upper end and on the other the radius’ lower end.), chip fractures, sagittal fractures, slab fractures and condylar fractures are often found in working horses. Within the joints the knuckles are known as Condyles, and fractures of the condyles usually start at the surface of the joint and then move up the bone. In racehorses, these fractures start at the fetlock go into the cannon bone. These fractures may seem sudden, but is caused by excessive trauma during the previous months. Periosteum inflammation is known as bucked shins. It is not a career threatening injury, but as it is the membrane covering the skin to which the tendons are attached that is inflamed, it creates severe discomfort and extreme pain for the horse.
Studies have proven that horses that are trained correctly and their resorption cavities have been able to heal during bone remodeling, suffer less injuries. If bucked shins can be prevented, the risk of fractures is lowered immediately. Effective and suitable training, especially in younger horses, can make a great difference in injuries and their severity.