Ex vivo biomechanical evaluation of an adhered fiberglass and polymethyl methacrylate sole-hoof wall cast on stabilization of type III distal phalanx fractures under simulated physiologic midstance loads.

OBJECTIVE: To evaluate the effect of the application of a novel fiberglass-glue cast (FGC) on the fracture gap width in experimentally created type III distal phalanx fractures in cadaveric specimens under simulated physiologic loads. STUDY DESIGN: Ex vivo biomechanical laboratory study. ANIMALS: Nine unilateral adult equine cadaver forelimbs. METHODS: Type III distal phalanx fractures were created in forelimb specimens, which maintained distal components of the passive stay apparatus. The fracture gap was measured at 5%, 20%, 25%, 50%, 75%, and 95% of fracture length (palmar articular border to solar margin) using D65Pr-PaDiO radiographs. The limb was axially loaded (700, 3600, 4600, and 6700 N) before, during, and after removal of a woven fiberglass cloth and polymethyl methacrylate cast that encompassed the sole and distal portion of the hoof wall (FGC). Fracture gap widths were compared among loads and treatments using a mixed model ANOVA. RESULTS: On average, under simulated physiological midstance loads, the fracture gap width was 0.2 mm smaller after FGC application, with the greatest decrease (0.5 mm) near the articular surface. On average, it was 0.3 mm smaller than after FGC removal. Fracture gap width was 0.1 mm greater when midstance loads transitioned from standing load to walking, trotting, and gallop loads. The fracture gap width increased by 1.3 mm with increasing distance from the articular surface. CONCLUSION: The FGC reduced the fracture gap width and prevented the fracture gap widening that occurred after FGC removal. CLINICAL SIGNIFICANCE: The findings support consideration of FGC use in the treatment of horses with type III distal phalangeal fractures.

Muscle tears as a primary cause of lameness in horses: 14 cases (2009-2016).

This study describes clinical and ultrasonographic findings and outcomes of horses with lameness associated with muscle tears. Records of horses diagnosed with muscle tears were retrospectively evaluated. Horses in which one or more muscle tears were confirmed ultrasonographically and lameness was associated with the tear were included in the study (n = 14). Eight horses had tearing of a single muscle, 6 horses had 2 or more muscles involved. Twelve of 14 horses survived to discharge and were alive at follow-up (8 to 90 months). Recovery time ranged from 6 to 52 weeks (mean: 19.8 weeks); 6 to 16 weeks for single muscle injuries and 12 to 52 weeks for multiple muscle injuries. Of the 12 long-term survivors 3 had chronic lameness/stiffness preventing return to their previous activity level and 9 returned to equal or greater level of activity. No statistically significant difference existed between outcomes and location of injury or number of muscles injured. Key clinical message: This study indicates that conservative management of muscle tears can result in favorable long-term outcomes.

Déchirures musculaires comme cause primaire de boiterie chez des chevaux: 14 cas (2009­2016). La présente étude décrit les trouvailles cliniques et échographiques ainsi que le devenir de chevaux avec une boiterie associée à des déchirures musculaires. Les dossiers de chevaux diagnostiqués avec une déchirure musculaire furent rétrospectivement évalués. Les chevaux chez qui une ou plusieurs déchirures musculaires furent confirmées par échographie et dont la boiterie était associée avec la déchirure furent inclus dans l'étude (n = 14). Huit chevaux avaient une déchirure de seulement un muscle, 6 chevaux avaient 2 muscles ou plus d'impliqués. Douze des 14 chevaux ont survécu jusqu'au congé et étaient vivants lors du suivi (8 à 90 mois). Le temps de guérison varia de 6 à 52 semaines (moyenne: 19,8 semaines); 6 à 16 semaines pour une blessure à seulement un muscle et 12 à 52 semaines pour des blessures musculaires multiples. Parmi les 12 survivants à long-terme, trois avaient une boiterie chronique/raideur empêchant un retour à leur niveau d'activité antérieur et neuf retournèrent à un niveau d'activité égal ou plus grand. Aucune différence statistiquement significative n'existait entre le devenir des chevaux et la localisation de la blessure ou le nombre de muscles blessés.Message clinique clé:Cette étude démontre qu'une gestion conservatrice des déchirures musculaires peut résulter en une issu favorable à long terme.(Traduit par Dr Serge Messier).