Biomedical Engineering Reference
In-Depth Information
andallowcellstoproliferatebetter.Herewedescribeourworkon
preclinical animal trials applying the above concept to regenerate
bone.
43.1 Introduction
New BTE methods are necessary to treat bone defects in orthope-
dic, plastic, and neurosurgical fields. Bone defect or bone shorten-
ingoccursafterexcisionofbonetumor,openfracture,osteomyelitis,
andpseudoarthrosis-associatedcongentialdiseasessuchasneurofi-
bromatosis and hemimelia. There have been many methods to treat
bone defects. These include autogenous bone grafting, allografting,
vascularized fibular graft, and distraction osteogenesis using the
Ilizarov method. There are limitations of these methods. Autoge-
nous bone grafting has a limitation of donor site morbidity. Allo-
grafting has problems, including the follow-up resorption, infection
transmission,orhighincidenceofrefractureduetoinsu
cientbone
conduction and induction. Vascularizing fibular grafting has good
vascularity, which can help control infection and promote new bone
formation. However, it requires long surgical time and extensive
experience to achieve good clinical results. Pioneered by Ilizarov,
distraction osteogenesis is a remarkably effective technique for
creatingnewbonetotreatlargebonedefectsresultingfromtrauma,
tumor resection, or limb length discrepancies.
1
−
4
Distraction osteo-
genesis using the Ilizarov method can induce the periosteal new
bone formation, and external fixator is utilized to apply 1 mm dis-
traction per day. This technique is useful and can induce new bone
formation without any bone grafting. However, one disadvantage
of distraction osteogenesis is prolonged external fixation, such as
large bone gaps or delay in bone formation in certain cases
5
−
7
—for
instance, the formation of1 cm new bonerequires at least 1 month.
Recently, osteogenic scaffolds using absorbable or nonab-
sorbable biomaterials have being investigated to repair bone
defects. Scaffolds can provide the osteoconduction effect as well as
a media to trap cells and allow them to proliferate and differenti-
ate.However,toachievetheosteoinductioneffect,theincorporation
of growth factors or stem cells is needed. Nonabsorbable materials
such as hydroxyapatite or ceramic have been used with advantages
Search WWH ::
Custom Search