Bone lengthening osteogenesis, a combination of intramembranous and endochondral ossification: an experimental study in sheep

Abstract

We evaluated the morphological features of the newly formed tissue in an experimental model of tibial callotasis lengthening on 24 lambs, aged from 2 to 3 months at the time of operation. A unilateral external fixator prototype Monotube Triax® (Stryker Howmedica Osteonics, New Jersey) was applied to the left tibia. A percutaneous osteotomy was performed in a minimally traumatic manner using a chisel. Lengthening was started 7 days after surgery and was continued to 30 mm. The 24 animals were randomly divided into three groups of 8 animals each: in Group 1, lengthening took place at a rate of 1 mm/day for 30 days; in Group 2, at a rate of 2 mm/day for 15 days; in Group 3, at a rate of 3 mm/day for 10 days. In each group, 4 animals were killed 2 weeks after end of lengthening, and the other 4 animals at 4 weeks after end of lengthening. To assess bony formation in the distraction area, radiographs were taken every 2 weeks from the day of surgery. To study the process of vascularization, we used Spalteholz’s technique. After killing, the tibia of each animal was harvested, and sections were stained with hematoxylin and eosin, Masson’s trichrome, and Safranin-O. Immunohistochemistry was performed, using specific antibodies to detect collagens I and II, S100 protein, and fibronectin. A combination of intramembranous and endochondral ossification occurred together at the site of distraction. Our study provides a detailed structural characterization of the newly formed tissue in an experimental model of tibial lengthening in sheep and may be useful for further investigations on callotasis.

Changes to the cell, tissue and architecture levels in cranial suture synostosis reveal a problem of timing in bone development

“…Whereas in distraction gaps the tissue between the ends of the mineralised bone is first subject to bleeding, coagulation, granulation tissue and fibrosis (Kokich, 1976;Shapiro, 2008), bone directly develops at the suture edges in craniosynostosis. In addition, in contrast to the distraction gap (Yasui et al, 1997;Jazrawi et al, 1998;Sato et al, 1998;Ploder et al, 2002;Lafuente et al, 2009;Forriol et al, 2010), our analyses of sutural sites showed no verification of enchondral and transchondroid types of osteogenesis.…”

In Vivo Mechanical Characterization of the Distraction Callus During Bone Consolidation

“…However, during the consolidation phase, bone volume is created quickly in a disorganized way with the aim of recovering the force sustained by the limb. 20,24,25,44 The device (instrumented fixator and acquisition system; Fig. 2) used in this study or similar designs increase the future possibilities of assessing consolidation in combination with conventional methods (such as Xrays or ex vivo tests).…”

“…Nevertheless, both methods have been proven inexact. 35,36,50 In addition, as these traditional techniques, many of the existing studies 3,5,6,13,20,24,25,27,34 are not able to provide the sufficient quantitative information that sometimes may be necessary; e.g., to evaluate the time to remove the fixator. Therefore, new quantitative techniques for assessing callus volume and material properties are required to optimize clinical treatment strategies.…”

“…As far as the authors know, most of the works referenced and others in literature focus on a single aspect of the process of distraction osteogenesis 2,3,[5][6][7]9,10,12,13,16,19,20,[23][24][25]27,28,30,34,37,45,50,51 Therefore, the aim of this work is to quantify and relate during the complete bone transport process quantifiable biological parameters (the bone tissue volume and its distribution in the distraction callus) with mechanical parameters (the force through the fixator and through the callus, and the callus stiffness during the consolidation phase of the process). Bone transport experiments were performed in sheep.…”

Intramembranous bone regeneration and implant placement using mechanical femoral marrow ablation: rodent models

“…This latter pathway, although also present in fracture repair, is integral to bone defect repair, distraction osteogenesis and implant fixation. 9,25,26 Like nearly all wound repair responses, intramembranous bone formation following marrow ablation has inflammatory, repair and remodeling phases each of which are time-dependent, characterized histologically and genetically. 4 These phases for intramembranous bone formation are distinct from endochondral-based fracture repair.…”