Histological findings of orthotopic bone formation after treatment with various concentrations of SDF-1 with/without BMP2.

(A) Representative histological sections 4 weeks post-surgery (trichrome staining, ×40 in the box). (B) Bone formation ratio (%) and newly formed bone area (mm²) were analyzed histomorphometrically. Concomitant BMP-2 and SDF-1 treatment did not significantly activate orthotopic bone formation compared to independent treatment with BMP-2 or SDF-1 alone (*, p < 0.05).