Table 5.

Comparison of similar studies to the current study

Variable	Bostrom et al. [7]	Egermann et al. [10]	Tang et al. [30]	Sarban et al. [current study]
Experimental model	Ulnar defect in rabbit (not an osteoporosis model)	Tibial osteotomy in overiectomized (OVX) sheep	Mandibular defect in OVX rat	Tibial defect in OVX rat
Source of BMP	rhBMP-2	Adenoviral transduction of mesenchymal stem cells and osteoblasts	Transfection of bone marrow stromal cells with plasmid	rhBMP-2
Carrier scaffold	Polylactic glycolic acid/blood clot	—	Macroporous coral hydroxyapatite	Absorbable collagen sponge
Radiology	Dose dependent response in the healing of defect	QCT analyses showed larger cross-sectional callus area.	Bone formation on the transfected bone marrow stromal cell seeded scaffold	Mean radiological score was significantly higher in the BMP-2/OVX group than the only OVX group
Biomechanics	Torsion test revealed BMP-2 group more stiffer than the control but it was not dose dependent	Bending and torsion tests showed stiffer callus tissue in the adenoviral BMP-2 group	—	Three-point bending test revealed higher load value in the BMP-2/OVX group than the its peer without BMP-2 application
Histology	Qualitative analyses revealed a dose dependent bone healing rate	Quantitative analyses showed no difference between the groups in terms of the number of inflammatory cells	Qualitative analyses showed the critic size defect completely filled by the trabecular bone at the end of 8-week in experimental group	Quantitative analyses revealed superior callus formation (better bone union, cortex remodeling and callus formation) in the BMP-2 groups
Bone mineral density measurement	—	QCT analyses showed higher mineral density in the adenoviral BMP-2	—	DXA measurements revealed higher BMD in the BMP-2 groups (data not presented)