CONDYLAR FRACTURES ISSUE 28_Jerkins feature.qxd 16/04/2013 22:32 Page 2
CONDYLAR FRACTURES
“Lateral condylar fractures form in a specific area of the bone and it has been shown that in this site, prior to fracture, bone can become very dense and hypermineralized”
A Thoroughbred undergoing an MRI examination while standing quietly with sedation
common fracture type across National Hunt racing. In flat racing, lateral condylar fractures are also all too common but pastern fractures on turf and proximal sesamoid bone fractures on all weather surfaces are more prevalent. The exact reasons why different racing formats, surfaces, and distances lead to different forms of fracture are still being teased apart. For lateral condylar fractures specifically, risk factors include a lack of fast work, first year of training, and racing first as three- or four-year-olds compared to two-year-olds. When the circumstances of the race in which the lateral condylar fracture occurs have been examined, firm going, longer distances, larger fields, and taking part in amateur jockey races have all been linked to a higher prevalence of this fracture type.
Precursors to fracture The condyles are the round prominences at the end of a bone that form part of the joint with the adjacent bone. In the cannon bones, there are two condyles, one on either side and thus they are named the lateral (outer) and medial (inner) condyles. Both lateral and medial condylar factures can occur and they can affect both the fore and hind limbs. Lateral condylar fractures form in a specific area of the bone and it has been shown that in this site, prior to fracture, bone can become very dense and hypermineralized. As a result, calcium crystals are deposited in the bone and there is a loss of collagen. Collagen is a key component of bone and other tissues that provides bendiness and the ability to withstand impact. Loss of collagen and build-up of dense and brittle tissue puts this area of the bone at risk of fracture. In some horses the fracture is so catastrophic that euthanasia is necessary. Fortunately, in many affected horses, the fractures can be repaired by placing screws across the fracture line either under anesthesia or, for the least complex configurations, under standing sedation (Stand and deliver – An important step forwards in equine fracture, Issue 26 – Autumn 2012). Nevertheless, even in the least severe cases, lateral condylar fractures can be career threatening.
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