Carpal Parameters on Dorsopalmar Radiographs of the Equine Carpus

Carpal conformation is considered to be a predisposing factor for joint damage which is common in racehorses. Radiography is the most accurate diagnostic tool to evaluate limb deformities. However, despite the accuracy, availability, and cost-effectiveness of this tool only a few conformational studies evaluating the equine carpal morphology have been published. Consequently, the established parameters are insufficient to represent this complex joint. Dorsopalmar view (DP) is the most relevant radiographic view to assess carpal deformity. This study identified a consistent equine carpal DP view and developed reliable and repeatable carpal parameters. Twenty forelimbs from 11 adult horses of different breeds and ages were used. Forelimbs were cut at the distal radius and mounted in an extended position, then radiographed using digital radiography. The DP for the carpus at zero° (ZDP) was defined and established using two landmarks. Specific radiographic features were selected as landmarks for developing carpal parameters. Establishing any parameter was based on an ability to identify its landmarks consistently. Repeatability of identified parameters was tested with each radiograph measured twice with an interval of at least one month. Ten carpal morphometrical parameters were developed. The study provided a base for measuring carpal conformation using radiographs.