A biodegradable scaffold for the treatment of a diaphyseal bone defect of the tibia.
The aim of this study was to compare angiogenesis and osteogenesis occurring within 8.0 mm diaphyseal defects created in canine tibiae treated using autograft or a biodegradable bone scaffold. All tibiae were reamed to 7.0 mm and fixed with a 6.5-mm statically locked intramedullary nail. Each of the 18 canines as allotted to one of three treatment groups: (1) left empty (N = 5), (2) treated with iliac crest autograft (N = 6), or (3) treated with a PLGA/calcium phosphate biodegradable scaffold (N = 7). Fluorescent markers were given at successive time periods: calcein green at 6 weeks, xylenol orange at 9 weeks, and tetracycline at 11 and 14 weeks. Animals were sacrificed at 15 weeks and their legs were perfused with a radio opaque compound. Samples were analyzed using Micro CT, bright-field microscopy and fluorescent microscopy. Scaffold samples were found to have significantly greater bone formation (p = 0.015) and blood vessel formation (p < 0.001) at their osteotomy sites than autograft samples. Bone formation rate in the periosteum was significantly greater in the autograft samples than the scaffold samples for all time periods. Bone formation at the osteotomy site was found to be significantly greater when associated with greater blood vessel formation (p = 0.026). The PLGA/calcium phosphate biodegradable scaffold we have employed supports angiogenesis within a segmental tibial defect that has adequate soft tissue coverage.
Division of Orthopaedics, Department of Surgery, University of Toronto, Toronto, ON, Canada.
Paul R T
PR
Kuzyk
Emil H
EH
Schemitsch
John E
JE
Davies
D020341:Absorbable Implants; D000818:Animals; D018786:Bone Substitutes; D016025:Bone Transplantation; D002130:Calcium Phosphates; D004195:Disease Models, Animal; D004285:Dogs; D005452:Fluoresceins; D005456:Fluorescent Dyes; D005594:Fracture Fixation, Intramedullary / Q000295:instrumentation / Q000379:methods; D017102:Fracture Healing / Q000502:physiology; D007085:Ilium / Q000637:transplantation; D019344:Lactic Acid; D018919:Neovascularization, Physiologic; D010012:Osteogenesis / Q000502:physiology; D010027:Osteotomy; D010636:Phenols; D011100:Polyglycolic Acid; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D011859:Radiography; D013454:Sulfoxides; D013752:Tetracycline; D013978:Tibial Fractures / Q000000981:diagnostic imaging / Q000473:pathology / Q000601:surgery*; D013997:Time Factors; D054457:Tissue Scaffolds; D014184:Transplantation, Homologous; D014992:Xylenes
D018786:Bone Substitutes; D002130:Calcium Phosphates; D005452:Fluoresceins; D005456:Fluorescent Dyes; D010636:Phenols; D013454:Sulfoxides; D014992:Xylenes; C083098:calcein green; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D011100:Polyglycolic Acid; D019344:Lactic Acid; C020243:calcium phosphate; D013752:Tetracycline; C016833:xylenol orange