Radiographic Texture of the Trabecular Bone in the Proximal Phalanx of Horses

Trabecular bone is highly dynamic in response to external and internal stimuli, and changes in its structure can be quantified through fractal analysis. However, fractal analysis is still an incipient technique in equine research. This study aimed to evaluate the complexity, heterogeneity, and density of the trabecular bone of the proximal phalanx (P1) of healthy adult horses of different breeds and sexes by measuring the values of fractal dimension (FD), lacunarity, and bone area fraction (BA/TA) in 65 radiographic examinations of the metacarpophalangeal joint and evaluate the agreement between the BoneJ and FracLac plugins for measuring FD. Regions of interest of 50 × 50 pixels were manually selected on the trabecular bone in the proximal epiphysis of the P1. No differences were observed for FD, lacunarity, and BA/TA between horses of different breeds and sexes (p > 0.1). The BoneJ and FracLac plugins showed no agreement when measuring FD (p < 0.01). Therefore, the radiographic texture of the trabecular bone of the P1 in horses had no influence depending on the analyzed breed or sex. The FracLac plugin measured higher FD values, and hence standardization using the BoneJ plugin is recommended. Further studies are required to evaluate other breeds, age groups, and training levels.