Bone Generation in the Reconstruction of a Critical Size Calvarial Defect in an Experimental Model

Abstract

This study was designed to investigate the optimal combination of known osteogenic biomaterials with shape conforming struts to achieve calvarial vault reconstruction, using a canine model. Eighteen adolescent beagles were divided equally into 6 groups. A critical-size defect of 6 x 2 cm traversed the sagittal suture. The biomaterials used for calvarial reconstruction were demineralized perforated bone matrix (DBM), recombinant human bone morphogenetic protein 2 (rhBMP2), and autogenous platelet-rich plasma (PRP). The struts used were cobalt chrome (metal) or resorbable plate. The groupings were as follows: 1) DBM + metal, 2) DBM + PRP + metal, 3) DBM + PRP + resorbable plate, 4) DBM + rhBMP2 + metal, 5) DBM + rhBMP2 + PRP + metal, and 6) DBM + rhBMP2 + resorbable plate. Animals were killed at 3 months after surgery. There was no mortality or major complications. Analysis was performed macroscopically and histologically and with computed tomography. There was complete bony regeneration in the rhBMP2 groups only. Non-rhBMP2 groups had minimal bony ingrowth from the defect edges and on the dural surface, a finding confirmed by computed tomographic scan and histology. Platelet-rich plasma did not enhance bone regeneration. Shape conformation was good with both metal and resorbable plate. rhBMP2, but not PRP, accelerated calvarial regeneration in 3 months. The DBMs in the rhBMP2 groups were substituted by new trabecular bone. Shape molding was good with both metal and resorbable plate.

BMP-2-Mediated Regeneration of Large-Scale Cranial Defects in the Canine: An Examination of Different Carriers

“…The trabecular nature of rhBMP-2-generated bone has been documented previously. 7,8,14 This gross disorganization resulted in variability across treatment groups with regard to the compactness of the newly formed bone. When compared side by side under identical magnification, groups B and C showed trabecular bone growth, with group C qualitatively superior Volume 127, Number 5 • Regeneration of Large Cranial Defects to group B.…”

“…Several experimental models have investigated how bone morphogenetic protein therapies can be safely expanded to address bony defects throughout the skeleton, including the calvaria. [7][8][9][10] Although the successful application of rhBMP-2 therapy to the calvaria would potentially obviate the need for autogenous tissue harvest, the unwanted effects of rhBMP-2 therapy must first be minimized before it can be considered a preferred therapy. The development of seromas and the formation of ectopic bone following rhBMP-2 treatment has been described previously.…”

Recombinant human bone morphogenetic protein-2 stimulates bone formation during interfrontal suture expansion in rabbits

“…[24][25][26][27][28] Although all concentrations of rhBMP-2 appeared to enhance bone formation on the perisoteal surface of the suture, the suture was fused with excessive bone formation, once exceeding the threshold of 0.1 mg/mL of rhBMP-2. If this threshold was not met, rhBMP-2 stimulated bone formation at the edges adjacent to the expanding suture.…”

Effects of Platelet-Rich Plasma and Recombinant Human Bone Morphogenetic Protein-2 on Suture Distraction Osteogenesis

“…On the contrary, some investigators have demonstrated no benefit or even a negative effect on bone regeneration with PRP. 23,24 It remains questionable whether or not the PRP can enhance new bone formation. In our study, the suture width was consistently less in the PRP gel group than in the control group, as shown on histological slices and micro-CT images (Figs.…”