Incidence, location and classification of 371 third carpal bone fractures in 313 horses

Abstract

Summary The medical records and radiographs of all horses with a third carpal bone fracture admitted to The Ohio State University Veterinary Hospital from 1979 to 1987 were reviewed. Three hundred and seventy‐one fractures were found in 313 horses; 57 per cent were Standardbreds, 41 per cent were Thoroughbreds, and only 1.6 per cent were Quarterhorses. All were young racehorses (average age = 3.1 years). Third carpal fractures occurred more frequently in the right limb (60 per cent) than the left limb (40 per cent); Thoroughbreds had a greater right‐left disparity (67.5 per cent R, 27.1 per cent L). Fractures were classified according to their size and anatomical location within the third carpal bone: incomplete fractures of the radial facet (type 1, N = 39), large proximal chip fractures of the radial facet (type 2, N = 140), small proximal chip fractures of the radial facet (type 3, N = 18), medial corner fractures (type 4, N = 13), frontal plane slab fractures of the radial facet (type 5, N = 93), large frontal plane slab fractures involving both the radial and intermediate facets (type 6, N = 35), fractures of the intermediate facet (type 7 N = 13), and sagittal slab fractures (type 8, N = 20). The incidence of each fracture type was significantly different between Standardbreds and Thoroughbreds. Type 1 and 2 fractures were more common in Standardbreds; type 5 and 6 fractures were more common in Thoroughbreds. Differences between these two breeds are related to the different gaits at which they race. The classification more accurately describes the extent of injury and the variation in fractures observed in this study than the traditional division as chips or slabs. A high quality skyline projection is important in correctly identifying these fractures; over 10 per cent of the fractures were detected only on this view.

A novel radiographic projection for the detection of sagittal plane slab fracture of the equine third carpal bone

“…The predominance of left-sided injuries in this report is notable and differs from previous reports of sagittal plane slab fractures of the third carpal bone [1,2]. Laterality of some orthopaedic injuries is recognised in racehorse populations and is primarily influenced by track configuration.…”

Fatal musculoskeletal injuries of Quarter Horse racehorses: 314 cases (1990–2007)

“…The limb prevalence is consistent with nonfatal third carpal bone fractures [55][56][57][58][59] and fatal scapular fractures in Thoroughbred and Quarter Horse racehorses. The limb prevalence is consistent with nonfatal third carpal bone fractures [55][56][57][58][59] and fatal scapular fractures in Thoroughbred and Quarter Horse racehorses.…”

Descriptive epidemiology of joint injuries in Thoroughbred racehorses in training

“…In this study, unilateral carpal injuries were more commonly seen in the right limb than in the left limb. Other studies have reported a predominance of carpal fractures in the right limb (Schneider et al 1988;Ramzan and Palmer 2010). The reason for this is unclear, but could be influenced by the direction of training.…”