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)

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)

Front fetlock joint angle (FA) measurement might predict musculoskeletal injury. This study aimed to identify an accurate reliable tool, and develop a consistent method for measuring the FA. Fetlock centre of rotation was identified radiographically. Goniometer measurements were validated on ten vertically fixed post-mortem distal forelimbs by positioning the centre of rotation of the goniometer on the approximate centre of rotation of the joint for five measurements of each FA at three day intervals and one measurement by another person (rater B). Both FA’s of fourteen sound horses standing squarely on a concrete floor were repeated before and after lifting the contralateral limb, which was flexed at the carpus and held at the same level as the carpus of the standing limb. Consistency of measurements was assessed using both fetlock joints of five horses standing squarely on a concrete floor measured six times in random order and then with the contralateral limb lifted using both front fetlocks of eight horses measured five times in random order. The repeatability coefficient was calculated with WinPepi v10.5 software. The centre of rotation was on or around the eminence of the lateral collateral ligament. The repeatability coefficient of the goniometer validation was 4.7°. The mean FA for rater A and B were not significantly different (161.4° versus 162.9°). FA’s were significantly less after lifting the contralateral limbs (P
Abdulrhman M. Alrtib, Helen M S Davies(7-2012)