Carpal conformation is thought to contribute to the frequency of carpal pathology so non-invasive measurement of carpal morphometry would be useful to identify joints at risk. However, there are scant radiographic morphometrical details for the carpals of Thoroughbred (TB) and Standardbred (SB) racehorses even though these breeds differ in the incidence of carpal damage. This study aimed to identify morphometrical similarities and differences in carpal conformation in TB and SB. Thirty carpal dorsopalmar radiographs (DP) were collected from 15 TB and 15 SB. All DP radiographs were at zero degrees or within the acceptable range of rotation. Twelve carpal radiographic parameters were selected and measured on each radiograph. Statistical analysis found significant differences in four carpal parameters. These parameters revealed that the middle carpal joint in SB was significantly more angled distomedially whereas the radial distal metaphysis showed a greater distolateral inclination in TB. The radiocarpal and the carpometacarpal articulations exhibited common features in the two groups of horses. These carpal traits in TB and SB highlight their potential association with loading distribution and pathology. Measuring carpi from untrained and injured horses is necessary to establish breed specific features for the ideal carpal conformation in each of these breeds.
Aiman Hussein Saleh Oheida, Abdulrhman Mohamed Salah Alrtib, Aiman Abdulghader Salim Shalgum, Mansur Ennuri Moftah Shmela, Mohamed A Marzok, Helen M S Davies(4-2019)

Several reports have discussed possible bony morphological causes of fetlock pathology but without relating them to its morphometry. Radiographic measurement is widely used in constructing numerical databases of bone morphometry. Such measurements would not be reliable unless all factors affecting the radiographs were considered. Therefore, this study aimed to establish a specific dorsopalmar view (DP) for fetlock radiographic measurements, and then to develop reliable and repeatable fetlock parameters that represent fetlock conformation on those DP radiographs. Ten cadaveric forelimbs from ten adult horses were cut at the distal third of the radius and mounted in a normal posture for DP radiography. Specific features on fetlock bones were used as landmarks to identify the DP at zero degrees. Other bony features were selected as landmarks for developing fetlock parameters on these radiographs. Twenty-seven parameters were designed in the form of angles (12) and ratios (15). The repeatability and consistency of each parameter was tested. A specific fetlock DP view was determined at zero degrees based on certain landmarks. All angular and ratio parameters showed high reliability and consistency in their measurements. The established parameters provide an opportunity to test the relationship between fetlock morphometrics and performance, or the likelihood of certain pathologies.
Abdulrhman Mohamed Salah Alrtib, Aiman Hussein Saleh Oheida, Mohamed Hamrouni S. Abushhiwa, Helen M S Davies(3-2019)

Relationships between carpal morphology and carpal pathology might assist in identifying horses at risk of carpal pathology. This study was aimed to investigate the hypothesis that carpal morphology is related to the incidence of carpal pathology in racing Thoroughbreds. Ten carpal parameters were used to measure carpal morphology on dorsopalmar (DP) carpal radiographs. Radiographs were collected from 19 experienced Thoroughbred race horses with no evidence of carpal damage(normal)and 72 horses with carpal damage (clinical). All radiographs were at a defined position called zero degrees (ZDP) or within an acceptable rotational range. Based on a P-value of < 0.05 and using the false discovery rate method to control Type I error, two parameters showed significant differences between normal and clinical horses. The angulation of the radial metaphysis and distal radius in relation to the angulation of the radial facet of the third carpal bone (C3) was significantly related to the occurrence of pathology in the bones of the middle carpal joint in Thoroughbred race horses. This study presented important features on DP radiographs that allowed identification of a carpal conformation associated with carpal damage in Thoroughbred race horses. Using such a highly specific, cost-effective and safe technique as a routine for examining yearling Thoroughbreds would assist in identifying horses with carpal conformation unsuited to racing.
Aiman Hussein Saleh Oheida, Abdulrhman Mohamed Salah Alrtib, Mohamed Hamrouni S. Abushhiwa, Christopher J. Philip, Helen M.S. Davies(1-2022)