Equine Podotrochlear Apparatus - Histologic Characterization

Background: The navicular syndrome may be associated with alterations in other podotrochlear apparatus components, such as the deep digital flexor tendon, collareral sesamoid and distal ligaments, bursa bone. However, clinical significance nature of these changes are not well understood, many descriptive reports about bone lesions rarely accompanied by a complete comprehensive comparison animals control group. aim this study was to described histologically findings podrotrochlear allowing understanding inserts their microscopic appearance, thus providing future recognize alterations.Materials, Methods & Results: Fourteen samples were taken out 44 equine thoracic limbs specimens, separated at radiocarpal joint Crioulo Thoroughbred horses, an average age 6.0-year-old, coming from private clinic southern Brazil. specimens refrigerated 4ºC then they sent University Federal Santa Maria (UFSM). Once laboratory, dissected isolate each one. Subsequently, transversal longitudinal bone, tendo, ligament, colateral collected which processed Veterinary Pathology Laboratory UFSM Catarina (UFSC). tissues fixed 10% formaldehyde solution for 14 days routinely histology. sectioned 3 µm stained using hematoxylin-eosin (H-E) routine method. samples, after fixation, underwent decalcified process formic acid-sodium citrate aqueous histopathology. Histologic tendons evaluation showed that it is arranged honeycombs fascicles transverse section observation. tendinous fibers have more compact aligned collagen arrangement due dense connective tissue. synovial membrane composed cubic pseudo conjunctival epithelium layer synoviocytes forming villi towards lumen. This characterization very similar membrane. collateral ligament perfectly aligned, occurring confluence some areas dissection adipose sesamoide fibers, loose tissue vascular stroma. articular surface layers chondrocytes embedded hyaline matrix. There clear differentiation between subchondral area fibrocartilage palmar aspect bone.Discussion: morphophysiological structures inside hoof capsule important recognition abnormalities possible hypothesis originates syndrome. These great relevance often limb lameness horses. normal macroscopic, ultrasonographic radiographic images along histomorphometric contributed comprehension consequently interpretation diseases.Keywords: apparatus, syndrome, histological findings.