Prevalences of lumbosacral articulation anatomic variants identified on nuclear scintigraphy and transrectal ultrasonography of Selle Français Warmbloods, French Standardbred Trotters, and Thoroughbreds and agreement between results from the imaging modalities.

This research involves a study on lumbosacral (LS) articulation in horses and its anatomical variations. Using nuclear scintigraphy and transrectal ultrasonography, the study categorizes these variations and further investigates concurrences between the results of both imaging methodologies.

Objective and Methodology

• The research aimed at identifying and categorizing the anatomic variations found on the lumbosacral (LS) articulation of horses, along with estimating the level of agreement between two imaging modalities- nuclear scintigraphy and transrectal ultrasonography.
• The study used pre-existing clinical records from January 2016 to December 2019, of 243 horses. These horses included 81 Selle Français Warmbloods, 81 French Standardbred Trotters, and 81 Thoroughbreds.
• The scintigraphic images were assessed by two independent observers who were unaware of each other’s evaluations, a process that aimed at classifying the LS articulation anatomic variants (termed as scintigraphic type). For measuring the intra- and interobserver agreement, specific metrics were calculated.
• Ultrasonographic images were examined by a single observer who was blinded to horse identity and the scintigraphic outcomes. They classified the LS intervertebral symphysis anatomic variant (termed as ultrasonographic grade). Following that, an agreement analysis was also executed comparing scintigraphic type and ultrasonographic grade.

Findings

• The study concluded that the scintigraphic classification system had excellent intra- and interobserver agreement suggesting it as a reliable method for classifying anatomical variants of LS.
• A moderate level of agreement (κ = 0.61; 95% CI, 0.52 to 0.70) was found between the scintigraphic type and the ultrasonographic grade.
• It was discovered that anatomic variants of the LS articulation were found in all groups under study.
• The distribution of these variants exhibited significant differences among the different breeds, but not in relation to the horse’s sex.

Implications and Future Research

• The findings suggest that understanding the anatomical variants of the LS articulation in horses is crucial to avoid possible misinterpretations in clinical settings.
• The study indicates a need for future research to understand any potential associations between the identified anatomic variants and LS lesions, their clinical manifestations, and their impact on horses’ athletic performance.