The mechanical integrity of healed diaphyseal bone defects grafted with calcium hydroxyapatite/calcium triphosphate ceramic in a new animal model.
The need for an animal model to test bone graft materials simulating a weight bearing clinical situation is identified.  The concept, design and operative detail of a new model is described.  This model involved the creation of a mid-diaphyseal wedge defect in the femur of the adult beagle which separated both cortices, plating with a six-hole dynamic compression plate, and allowed immediate full weight bearing.  At six months plates were removed and immediate weight bearing was allowed for an additional six months to sacrifice.  The initial animal project utilizing this model to evaluate a hydroxyapatite based synthetic graft material was performed using 12 dogs.  In addition to the operative procedure, the retrieval testing in torsion of 12 healed grafted bones and their 12 contralateral unoperated controls is described and evaluated.  Results showed no statistically significant difference between the torsional strength of test and control femurs (p less than or equal to 0.05).  In addition, the future development of the model is discussed.
Black
R J
RJ
Orthopaedic Surgery, University of Mississippi Medical Center, Jackson.
Zardiackas
L D
LD
Teasdall
R
R
Hughes
J L
JL
D000818:Animals; D016025:Bone Transplantation; D002130:Calcium Phosphates; D002516:Ceramics; D004195:Disease Models, Animal; D004285:Dogs; D005069:Evaluation Studies as Topic; D005260:Female; D005264:Femoral Fractures / Q000601:surgery*; D005592:Fracture Fixation / Q000379:methods*; D017102:Fracture Healing; D006882:Hydroxyapatites; D008422:Materials Testing; D013718:Tensile Strength; D016474:Weight-Bearing