Objective: Metacarpophalangeal joint (MCPJ) radiographic parameters were developed to evaluate MCPJ conformation of equine forelimbs, but the effect of joint rotation during radiography on these parameters has not been reported. The current study examined the effect of the rotation around the vertical axis of MCPJ on 27 MCPJ parameters (12 angles and 15 ratios) and identified the acceptable range of rotation at which minimal amount of changes occurred in these parameters. Design: Descriptive study Animals: MCPJs of seven right forelimbs from seven different horses with no MCPJ abnormalities. Procedures: MCPJs of seven right equine forelimbs were loaded in a load cell to obtain the normal MCPJ angle. They were frozen at −20C° and then scanned using a CT-scan machine. The collected slices were reconstructed to obtain a 3D model of MCPJs, and the dorsopalmar view at zero angle (ZDP) were identified. The view was then rotated around the vertical axis of MCPJ. Snapshots were taken for MCPJ at −10°, −5°, Zero, +5° and +10° angles. All the parameters were measured on the total 35 radiographs and statistically analysed. Differences were estimated per 5° of MCPJ rotation for all the parameters. Results:Generally, the ratio parameters were less affected than the angular parameters during MCPJ rotation. Conclusion and clinical relevance: Rotational angles of vertical ±10° from ZDP were considered as an acceptable range for reliable radiographic measurements of MCPJ parameters. Keywords Equine; fetlock; morphometry; radiology; rotation
Abdulrhman Mohamed Salah Alrtib, Aiman Hussein Saleh Oheida, Mohamed Hamrouni S. Abushhiwa, Helen M.S. Davies(12-2021)

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)

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)