Influence of the overall stiffness of a load-bearing porous titanium implant on bone ingrowth in critical-size mandibular bone defects in sheep

Abstract

The aim of this work was to assess the influence of reduction of the apparent mechanical properties of fully load-bearing porous titanium implants used in mandibular bone defects. Segmental 18mm long bone defects were created bilaterally in the lower jaws of adult ewes. One group of 6 ewes (group A) was treated with load-bearing 'rigid' (high stiffness) porous implants on the right side, and with control on the left side. A second group of 6 ewes (group B) was treated with 'flexible' porous and control implants exhibiting apparent mechanical properties ten times lower than the rigid implants. The mechanical behavior of the reconstructed hemi-mandibles was assessed by cantilever testing and bone ingrowth into the segmental defects was assessed by BV/TV measurement within the implant using micro-CT 12 weeks after implantation. A significantly higher rigidity was identified for porous implants compared with control implants at the anterior interface in group B. BV/TV of porous implants was significantly higher than that of control implants in group A. BV/TV differences were significant between porous and control implants in group B and were homogeneous along the main axis. Significantly higher BV/TV was identified in most sub-volumes of group B porous implants compared with group A. This work highlights the critical importance of the tuning of scaffolds to promote bone ingrowth with reference to the local strains occurring within the porous scaffold, which in this application was achieved using fully load-bearing low-stiffness porous titanium implants.

Biomaterials-aided mandibular reconstruction using in vivo bioreactors

“…Given that the study was not designed to determine the extent of periosteal reaction in the healing of the defect alone, it is difficult to separate out these factors. However, it is of note that other ovine mandibular defect models of similar duration have been shown not to heal within 12 wk without further intervention (35), suggesting that the periosteal reaction alone would not have been sufficient for the degree of postreconstruction regeneration observed in this study. In addition to the periosteal reaction, it is possible that other sources of inflammation could have caused additional bony growth.…”

“…8 G and H). Lack of mandibular hardware osteointegration has been observed by multiple groups in ovine studies and has been speculated to be due to the lateral mastication motion of ruminants (34,35). Signs of a periosteal reaction, an inflammatory response in response to disruption of the periosteum, were observed in all of the reconstructed hemimandibles (Fig.…”

Novel standardized massive bone defect model in rats employing an internal eight‐hole stainless steel plate for bone tissue engineering

“…Moreover, the precise cellular and molecular mechanisms of bone repair are difficult to dissect. Studies based on large animal models focus on the histopathological progression of bone defect repair, with little attention to the mechanisms of bone repair or the fate and homing of the cells seeded on the implant (Schouman, Schmitt, Adam, Dubois, & Rouch, ). Thus, establish a reliable large segmental defect model in small animals is urgently required (Histing et al, ; Manassero et al, ).…”

Experimental Characterization of the Primary Stability of Acetabular Press-Fit Cups with Open-Porous Load-Bearing Structures on the Surface Layer

“…A large number of investigations are therefore concerned with the implementation of implant surfaces with biocompatible or bioactive properties [17][18][19][20]. The aim is to establish conditions that will optimally assist bone in growing in order to achieve maximum secondary stability [21][22][23][24][25].Numerical simulations are also frequently used in the area of implant development as an indispensable link between constructive development ideas and experimental testing [26][27][28][29][30]. The success of an implantation is determined not only by secondary stiffness but also by primary anchoring strength [29,31,32].…”

“…A large number of investigations are therefore concerned with the implementation of implant surfaces with biocompatible or bioactive properties [17][18][19][20]. The aim is to establish conditions that will optimally assist bone in growing in order to achieve maximum secondary stability [21][22][23][24][25].…”