Quantitative evaluation of bone development of the distal phalanx of the cow hind limb using computed tomography

Abstract

Computed tomography (CT) was performed on 400 claws (200 inner and 200 outer claws) of 100 pairs of bovine hind limbs to investigate the etiological theory that an exacerbating factor for ulceration is exostosis of the tuberculum flexorium within the distal phalanx. A variety of morphological changes of the tuberculum flexorium of bovine hind limb claws was visualized by 3-dimensional CT, and the geometry of these claws suggested a growth pattern of bone development with respect to the assumed daily loading patterns. This growth occurs initially at the abaxial caudal aspect of the distal phalanx and is followed by horizontal progression toward the axial aspect. The length of downward bone development on the solar face of the distal phalanx was 2.73±1.32 mm in the outer claws, significantly greater than in the inner claws (2.38±0.96 mm). Ratios of downward (vertical) bone development to the thickness of the subcutis and the corium (VerBD ratios) did not differ between the outer and inner claws (36.7 vs. 38.3%, respectively). Ratios of horizontal bone development to the axial-to-abaxial line of the tuberculum flexorium (HorBD ratios) were approximately 60% for both outer and inner claws. These quantitative measures regarding horizontal and vertical bone development within the distal phalanx were positively correlated with age and VerBD ratios (r=0.53 and r=0.36 for the inner and outer claws, respectively). Correlations between claw width of the outer claw and length of vertical bone development (r=0.43), the HorBD ratio (r=0.51), and the VerBD ratio (r=0.42) suggested that the relative size difference between the inner and outer claws enhances bone development in the outer claw. Correlation coefficients between VerBD and HorBD ratios (r=0.52 and 0.63 for the inner and outer claws, respectively) suggested that horizontal and vertical bone development occurs as a synchronized process within the tuberculum flexorium. This age-related progress of bone development within the tuberculum flexorium is associated with increased exposure to several exacerbating factors and the laminitic process.

Morphologische Untersuchungen tiefreichender Klauenerkrankungen beim Rind

“…Das bedeutet, dass Klauen mit einem RSG ohne nachweisbare Klauenbeinveränderungen eine vergleichsweise günstigere Prognose aufweisen (23,32). Mehrere Autoren vertreten die Ansicht, dass einer abweichenden Morphologie des Tuberculum flexorium in Bezug auf die Abheilung und Rezidivrate eine gewisse Schlüsselrolle zukommt (4,23,32,46). Des Weiteren führten bei einer Klaue periostale Knochenzubildungen am Margo coronalis und an der Seitenfläche des Klauensesambeins zu einer knöchernen Verbindung zwischen Klauen-und Klauensesambein.…”

“…Das Klauenbein unterliegt im Laufe des Lebens je nach Alter und Körpergewicht der Tiere mannigfaltigen Veränderungen (39,41). Am Tuberculum flexorium beginnt an der abaxialen Seite beim 6 Jahre alten Tier eine exostosenartige Zubildung nach kaudal und distal, die mit dem Alter zunimmt (37,41,46). Dadurch wird die Sohlenfläche des Klauenbeins deutlich rauer.…”

“…Dadurch wird die Sohlenfläche des Klauenbeins deutlich rauer. Ein entsprechend vergrößerter Beugeknorren prädisponiert diese Stelle für die Bildung von Sohlengeschwüren (25,46). Zusätzlich können die Gelenkkapsel des Klauengelenks und die Sehnenscheide der tiefen Beugesehne verknöchern, was im Extremfall zur Verwachsung des Klauenbeins mit dem Klauensesambein führt (37,41).…”

Effects of mechanical loads on the deformation and health status of claws in dairy cows

“…Moreover, cows could avoid partial support of their claws by placing their feet on the slats, but we have no indication at all that they do so . Bone development within the tuberculum flexorium contributes to the development of sole haemorrhages and sole ulcers (Tsuka et al, 2012;Newsome et al, 2016). According to Newsome et al (2016), the process is stimulated by claw horn disruption lesions and increases with aging.…”

“…According to Newsome et al (2016), the process is stimulated by claw horn disruption lesions and increases with aging. Although the mechanism behind this bone formation in unclear, it is hypothesized that laminitis related 'sinking' of the distal phalanx is involved (Tsuka et al, 2012). This phenomenon probably contributes to the concentration of strain in the typical sole ulcer area.…”