There are many reports describing fractures in the bony elements of the equine fetlock joint and a few of these discuss possible relationships of these fractures to the mechanical loading of these bones. The likelihood of fracture must be related to the size and shape of bones involved, but information concerning the normal range in size and shape of these bones in horses is lacking. This study aimed to identify morphometrical variations of these bones within different groups of horses. Right and left metacarpal, proximal phalangeal and proximal sesamoid bones were collected from 10 Thoroughbreds (TB), five Standardbreds (SB) and eight Ponies (P) euthanized for non-orthopaedic reasons. All bones were boiled, cleaned and dried. Dimensional parameters were measured using a custom-built apparatus, calliper and plastic tape. The width and depth of the medial condyles of Mc3 were greater than the lateral condyles in all groups. The length to the lateral condyle was greater than the length to the medial condyle of Mc3, and the lengths of the lateral sides of the Mc3 and P1 bones were greater than the lengths of the medial sides in both forelimbs of all groups. The lateral sesamoids were similar to, or larger than, the medial sesamoids in all dimensions. There were some morphometrical variations in the bony elements of the equine fetlock joints in all groups.
Abdulrhman Mohamed Salah Alrtib, C J Philip, Aiman Hussein Saleh Oheida, Helen M S Davies(4-2012)

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)

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)