Microstructural Properties of the Distal Growth Plate of the Rabbit Radius and Ulna: Biomechanical, Biochemical, and Morphological Studies

Abstract

The purposes of this study were to define the tensile properties of each zone of the rabbit growth plate and to correlate them with the microarchitecture and biochemical composition of the zones. The epiphysis-growth plate-metaphysis complex was obtained from the radius and ulna of 20 8-week-old rabbits.Four dye markers were placed on thc growth plate. Thc complcx was loaded to failure with a tensilc testing machine, and the strain behavior was recordcd simultaneously with a microscope. a charge-couplcd device camera, and a video dimension-analyzer system. Thc collagenous fiber architecture of each zone was examined with a microscope. and the collagen content of each zone was also determined. The tangent modulus oP the resting zone was 75% stiffer than that of the other two zones. Thc highest values for strain at failure and energy absorbed to failure were observed in the hypertrophic zone. and the total collagen content was highest in the proliferating zone. The collagen fibers wcre more randomly aligned in the resting zonc than in the other two zones. The diversity observed in the microarchitecture of the rabbit growth plate correlates with the zone-dependent differences in its mechanical propertics. YoshidaM: [The effect of maturation on biomechanical properties of cpiphyseal plate in the rabbit.] J Kyoto Pref Univ Med 104:617-629, 1995

Osteoblasts Generate Harder, Stiffer, and More Delamination-Resistant Mineralized Tissue on Titanium Than on Polystyrene, Associated With Distinct Tissue Micro- and Ultrastructure

“…The association of collagen architecture and degree of interfibrillar mineralization with mechanical properties of bone has been reported. (15)(16)(17)(18)(19)(20) In addition to the effect of matured mineral distribution, uniform and dense collagen deposition in the mid and outer areas of tissue on titanium, as shown in the Results section, may have caused its increased hardness and elastic modu-lus. The boosted collagen deposition on titanium culture was in accordance with the upregulated expression of collagen I and III genes.…”

“…(14) The degrees of collagen crosslinking, orientation, and density all affect the deposition of the extracellular matrix and, in turn, the mechanical properties of bone. (15)(16)(17)(18)(19)(20) There may be a synergistic effect of mineralization and collagen fibrillar formation. (21) Despite the considerable progress of titanium implant research, (22,23) there are still critical gaps in knowledge of the biological mechanisms underlying bone-titanium integration.…”

Mechanical environment alters tissue formation patterns during fracture repair

“…Progressive translations towards the posterior surface (in the x-direction) were applied to the distal pin tract to create bending, while displacement in the y-(medial-lateral) and z-(axial) directions were constrained. Material properties were assigned to cortical bone (E = 18,668 MPa; v = 0.30 [14]), cartilage (E = IS MPa, Y = 0.47 [8]) and connective tissue (E = 3.0 MPa, v = 0.40 [5]) elements based on reported values. Models were analyzed using an element-by-element preconditioned conjugate gradient technique with a convergence tolerance of 1 .…”

Distinct developmental changes in the distribution of calcium, phosphorus and sulphur during fetal growth‐plate development

“…These include many proteins that control cell differentiation directly (see reviews by Kronenberg, 2003;Lefebvre & Smits, 2005) as well as factors that have an indirect effect via changes to the extracellular matrix. With regard to the latter, the stiffness of growth plate tissue is known to change with height (Fujii et al 2000;Radhakrishnan et al 2004). This is the result of changes in swelling pressure associated with the constitution of proteoglycans (Gakunga et al 2000), which changes over the matrix metalloproteinases (MMPs), expressed by hypertrophic chondrocytes in growth plates and early osteoarthritic cartilage (der Mark et al 1992;Kirsch et al 2000;Wu et al 2002a;Ortega et al 2004;Tchetina et al 2005).…”

“…These include many proteins that control cell differentiation directly (see reviews by Kronenberg, 2003; Lefebvre & Smits, 2005) as well as factors that have an indirect effect via changes to the extracellular matrix. With regard to the latter, the stiffness of growth plate tissue is known to change with height (Fujii et al. 2000; Radhakrishnan et al.…”