Increased Bone Formation Using Calcium Sulfate-Calcium Phosphate Composite Graft

Abstract

Calcium phosphates (CaPO4) and faster-resorbing calcium sulfate (CaSO4) are successfully employed as synthetic bone grafts for treatment of contained defects. We used a canine critical-sized bone defect model to study an injectable CaSO4/CaPO4 composite graft that incorporated a matrix of CaSO4 and dicalcium phosphate dihydrate into which beta-tricalcium phosphate granules were distributed. The area fraction, ultimate compressive stress, and elastic modulus of restored bone and the relative rates of material resorption were compared between the CaSO4/CaPO4 composite graft and pure CaSO4 pellets and to normal canine bone. The area fraction of bone in stained sections and the ultimate compressive stress of the regenerated bone were greater using the CaSO4/CaPO4 composite graft compared to pure CaSO4 pellets after 13 and 26 weeks and were greater than normal bone. The elastic modulus of restored bone in defects treated with CaSO4/CaPO4 composite graft was greater than in defects treated with CaSO4 pellets after 26 weeks, but similar to specimens of normal bone. A small amount of CaSO4/CaPO4 composite graft and no CaSO4 pellets remained after 13 or 26 weeks. This novel CaSO4/CaPO4 composite holds promise for clinical applications where a strong, injectable, slower-resorbing, and biocompatible bone graft substitute would be advantageous.

The Synergistic Effect of Autograft and BMP-7 in the Treatment of Atrophic Nonunions

“…Nevertheless, it is also associated with limited availability, longer operative time, and donor site morbidity [2]. For these reasons, other methods of biologic enhancement are currently the center of attention and the subject of a substantial amount of biomedical research [21,30,44,46].…”

Function After Injection of Benign Bone Lesions with a Bioceramic

“…Each author certifies that his or her institution approved the human protocol for this investigation, that all investigations were conducted in conformity with ethical principles of research, and that informed consent for participation in the study was obtained. [16,21,32] and osteoconductive [16,21,32]. Furthermore, they do not contain potent cytokines [16,21,32], which may be contraindicated in the presence of tumors.…”

“…Traditionally, the autogenous bone graft has been the gold standard for all grafting procedures [16,32]. Limited supply and substantial donor site morbidity, however, make this option less desirable [2,3,8,10,12,13,23,26,28].…”

“…[16,21,32] and osteoconductive [16,21,32]. Furthermore, they do not contain potent cytokines [16,21,32], which may be contraindicated in the presence of tumors. In a selective review, Rougraff documented the limited published data on the use of bone graft substitutes in orthopaedic oncology [24].…”

“…Recently, an injectable CaSO 4 -CaPO 4 composite graft material with high compressive strength but an intermediate degradation profile has become available [32]. A preclinical canine study showed this material to be superior to CaSO 4 regarding the quantity and quality of bone formed in a contained humeral defect [30][31][32].…”