CONDYLAR FRACTURES ISSUE 15.qxd:Jerkins feature.qxd
27/1/10
18:19
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CONDYLAR FRACTURES
The filly Eight Belles finished a gallant second to Big Brown in the Kentucky Derby before suffering catastrophic condylar frac tures in both front fetlocks leaving the racetrack veterinarians with no option but euthanasia
Condylar fractures are arguably the most common type of fracture suffered by the Thoroughbred racehorse. However, veterinarians have given them a slightly cryptic ‘pet-name’ so that many do not understand them quite as well as they would like. They are simply fractures of the lower cannon bone that extend into the fetlock joint and there are two types – outside or ‘lateral’ condylar fractures, and inside or ‘medial’ condylar fractures. By James Tate BVMS MRCVS
F
RACTURES of the cannon bone are the most common fracture of the racehorse, and by far the most widely-seen type of cannon bone fracture is the ‘condylar fracture’ by which the front legs are more frequently affected than the hind legs, while outside or ‘lateral’ condylar fractures are seen more often than inside or ‘medial’ condylar fractures. All types of condylar fractures are common, from minor stress fractures to more serious displaced fractures. According to David Nunamaker, a leading researcher in the field of equine orthopedics and professor at the University of Pennsylvania School of Veterinary Medicine’s New Bolton Center, lateral condylar fractures are the most common type of fracture with which he is presented. There are numerous examples of great racehorses that have suffered condylar fractures and had them successfully repaired, such as 2005 Preakness and Belmont winner Afleet Alex. However, severe, displaced, lateral condylar fractures like those suffered
by talented filly Eight Belles are also seen frequently and are in fact the most common cause of equine fatality on the racetrack in the United Kingdom (Parkin et al. Equine Veterinary Journal 2005).
An outside or lateral condylar fracture of the right fore fetlock. There is of ten swelling on the side of the fracture as well as increased joint fluid
Clinical Examination Unsurprisingly, the severity of the fracture determines the level of lameness and the amount of swelling associated with the fetlock joint and lower cannon bone. Injuries can be caused by repeated stress or a single event but there is usually a specific time when the fracture becomes apparent. For example, a severe displaced condylar fracture is usually found either during or shortly after exercising or racing; whereas a non-displaced ‘stress’ condylar fracture may be found at evening stables or indeed the day after it actually occurred. As the fracture extends into the fetlock joint, there is usually an increased amount of joint fluid and the fetlock joint is sore to manipulate and flex. Generally, the more severe the fracture the easier it is to diagnose
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