Biology subjects

Irandoust, S.

Publications and source records attributed to Irandoust, S..

3 recordsLinked to original sources

bioRxiv2025

Risk assessment for condylar stress fracture in elite racing Thoroughbreds using standing computed tomography-based virtual mechanical testing

BackgroundCondylar stress fracture of the third metacarpal bone is a common catastrophic musculoskeletal injury in Thoroughbred racehorses. Condylar stress fracture is associated with parasagittal groove (PSG) subchondral osteolysis. Standing computed tomography (sCT) imaging allows for sensitive identification of this fatigue-induced structural change, an early form of subchondral bone injury (SBI), but there is not yet an objective method for identifying racehorses at heightened risk of condylar stress fracture. ObjectivesTo estimate PSG first principal strain in elite Thoroughbred racehorses that have undergone subjective risk assessment using sCT fetlock screening. Study designRetrospective clinical study. MethodsWe used fetlock sCT images from 9 thoracic limbs from 7 Thoroughbred racehorses. A tuned, validated 3D finite element (FE) analysis approach was used as a virtual mechanical test to estimate PSG first principal strain in the distal third metacarpal bone (MC3) from these joints. Virtual mechanical testing results were compared with a subjective clinical risk assessment using an established screening approach by Racing Victoria. ResultsMC3 condyles with PSG SBI consistently and significantly displayed increased levels of first principal strain throughout the PSG. We found focal strain concentrations associated with the anatomical location of SBI compared to condyles with no evidence of SBI in the PSG. Clinical diagnosis of SBI with focal osteolysis, FE-predicted strain elevation, and clinical risk assessment were concordant with recall and precision of 0.86. Main limitationsThe sample size was small, and our virtual mechanical testing protocol does not account for whole-joint physiology. ConclusionsRisk assessment through screening with sCT is an established approach to injury prevention in racing Thoroughbreds. Concordance of a current clinical risk assessment approach by Racing Victoria with objective FE analysis of principal strain in sites of SBI in the present study suggests 3D FE analysis using a validated pipeline is an important new approach for routine assessment of risk of MC3 condylar stress fracture in Thoroughbred racehorses.

bioengineering↗

bioRxiv2024

Tuning and validation of a virtual mechanical testing pipeline for condylar stress fracture risk assessment in Thoroughbred racehorses

Condylar stress fracture of the third metacarpal/metatarsal bone (MC3/MT3) in Thoroughbred racehorses is a common catastrophic injury, putting racehorse and jockey safety at risk. Microdamage forms in the distal MC3 and may result in strain elevation and higher risk of stress fracture, directly and through focal osteolysis resulting from the associated process of repair by remodeling in the condylar parasagittal grooves (PSG). Standing computed tomography (sCT) is a practical screening tool for detection of fatigue-induced structural changes, but the clinical interpretation remains subjective. The goal of this study was to develop and validate a sCT-based subject-specific finite element analysis (FEA) pipeline for virtual mechanical testing of the distal MC3. Twelve (n=12) MC3 condyles with available ex vivo strain were selected. Half of the specimens were used for tuning of the Youngs modulus in fatigue sites, and the other half to examine validity of the pipeline for prediction of PSG strain. The tuned model improved prediction of strain and predicted higher strain in bones with PSG lysis over the untuned model, which is an essential feature for a diagnostic screening tool. The presented pipeline is expected to assist clinicians with interpretation of sCT-detectable structural changes and ultimately condylar fracture risk assessment.

bioengineering↗

bioRxiv2023

Comparison of radiography and computed tomography for condylar fracture risk assessment in Thoroughbred racehorses

BackgroundCatastrophic injury has a low incidence but leads to the death of many Thoroughbred racehorses annually. Effective screening for injury risk needs to solve the false negative diagnostic sensitivity problem. ObjectivesTo determine sensitivity, specificity, and reliability for condylar stress fracture risk assessment from fetlock digital radiographs (DR) and standing computed tomography (sCT) imaging (Asto CT Equina(R)). Study designControlled ex vivo experiment. MethodsA blinded set of DR and sCT images of the thoracic limb fetlock were prepared from 31 Thoroughbred racehorses and reviewed by four veterinarians. Observers evaluated the condyles and parasagittal grooves (PSG) of the third metacarpal subchondral bone (MC3) for the extent of dense bone and lucency/fissure and assigned a risk assessment grade for condylar stress fracture based on imaging findings. Sensitivity and specificity for detection of subchondral structural changes in the condyles and PSG of the third metacarpal bone and for risk assessment for condylar stress fracture were determined by comparison with a reference assessment. Agreement between each observer and the reference assessment and reliability between observers were determined. Intra-observer repeatability was also assessed. ResultsIntra-observer repeatability was identified for both DR and sCT imaging. Sensitivity for detection of structural change was lower than specificity for both imaging methods and all observers. For horses with a normal level of risk, observer assessment often agreed with the reference assessment. Sensitivity for risk assessment was lower than specificity for all observers. For horses with a high risk of serious injury, observers generally underestimated the level of risk. Diagnostic sensitivity of risk assessment was improved with sCT imaging, particularly for horses with elevated risk of injury. Assessment reliability was better with sCT than DR. Main limitationsThe ex vivo study design influenced DR image sets regarding limb positioning and image contrast compared with in vivo DR imaging. ConclusionsRisk assessment through screening with diagnostic imaging is a promising approach to improve injury prevention in racing Thoroughbreds. Knowledge of sensitivity and specificity of fetlock lesion detection by DR and sCT provides critical guidance regarding development of improved screening programs for racehorses using diagnostic imaging. We found improved detection of MC3 subchondral structural change and risk assessment for condylar stress fracture with sCT ex vivo.

physiology↗