A Biomechanical Evaluation of Auricular Cartilage Autografts in Orbital Floor Defect Repair.

Objective: Auricular cartilage is used as a surgical implant in the management of orbital floor fractures. However, no specific parameters exist regarding the use/limitations of this potential graft. In order to determine the mechanical efficacy of adult auricular cartilage grafts, a mechanical model was developed and studied for structural threshold size limits.

A novel stress distribution organ in the arthropod exoskeleton.

The vertebrate endoskeleton possesses a massive internal network of load-distributing trabeculae that in most locations accounts for the vast majority of bone cross sectional area. In contrast, arthropods rely on the external cuticle and its intermittent outpocketings to distribute the daily stresses of physiological loading. One of the constraints of the arthropod exoskeleton is the necessity to house the musculature involved in locomotion, feeding and etc.

Offender-victim body mass ratio and the decision to arrest in cases of intimate partner violence.

As a result of the growing trend toward criminalisation of cases of domestic violence, there has been a great increase in the number of jurisdictions in the United States that have implemented 'pro-arrest' and 'mandatory arrest' laws. One of the objectives of this legislation is to encourage arrest when there is probable cause to believe that an assault has occurred. Along with the increase in the overall rate of arrest for intimate partner violence there has been a dramatic increase in the arrest of both the parties involved in an incident.

Mechanical stimulation alters tissue differentiation and molecular expression during bone healing.

Further understanding of how mechanical cues modulate skeletal tissue differentiation can identify potential means of enhancing repair following injury or disease. Prior studies examined the effects of mechanical loading on osteogenesis, chondrogenesis, and fibrogenesis in an effort to enhance bony union. However, exploring how mechanical stimuli can divert the bone healing process towards formation of other mesenchymal tissues, as an endpoint, may elucidate new avenues for repair and regeneration of tissues such as cartilage and fibrous tissue.

Effects of the local mechanical environment on vertebrate tissue differentiation during repair: does repair recapitulate development?

The local mechanical environment is a crucial factor in determining cell and tissue differentiation during vertebrate skeletal development and repair. Unlike the basic response of bone to mechanical load, as described in Wolff's law, the mechanobiological relationship between the local mechanical environment and tissue differentiation influences everything from tissue type and molecular architecture to the formation of complex joints. This study tests the hypothesis that precisely controlled mechanical loading can regulate gene expression, tissue differentiation and tissue architecture in the adult skeleton and that precise manipulation of the defect's local mechanical environment can initiate a limited recapitulation of joint tissue development.

Fracture healing as a post-natal developmental process: molecular, spatial, and temporal aspects of its regulation.

Fracture healing is a specialized post-natal repair process that recapitulates aspects of embryological skeletal development. While many of the molecular mechanisms that control cellular differentiation and growth during embryogenesis recur during fracture healing, these processes take place in a post-natal environment that is unique and distinct from those which exist during embryogenesis. This Prospect Article will highlight a number of central biological processes that are believed to be crucial in the embryonic differentiation and growth of skeletal tissues and review the functional role of these processes during fracture healing.

The effect of recombinant human osteogenic protein-1 (bone morphogenetic protein-7) impregnation on allografts in a canine intercalary bone defect.

The utility of cortical allografts in repairing large bone defects is limited by their slow and incomplete incorporation into host bone. In order to determine the effects of recombinant human osteogenic protein-1 (rhOP-1) impregnation on allograft incorporation, we used a canine intercalary bone defect model. Bilateral resection of a 4 cm segment of the femoral diaphysis and reconstruction with structural bone allografts were performed.

Induction of a neoarthrosis by precisely controlled motion in an experimental mid-femoral defect.

Bone regeneration during fracture healing has been demonstrated repeatedly, yet the regeneration of articular cartilage and joints has not yet been achieved. It has been recognized however that the mechanical environment during fracture healing can be correlated to the contributions of either the endochondral or intramembranous processes of bone formation, and to resultant tissue architecture. Using this information, the goal of this study was to test the hypothesis that induced motion can directly regulate osteogenic and chondrogenic tissue formation in a rat mid-femoral bone defect and thereby influence the anatomical result.