Figure 3a: (A) Safranin-O staining and the cartilage degradation score of the medial tibial cartilage of Runx2–/– and wild-type (WT) littermates, Arrowheads indicate the level of tidemark; (B) Anteroposterior X-ray features, Safranin-O staining, and the osteophyte formation score 12 weeks after surgery, Means (symbols or bars) ± SEM (error bars), *P<0.01 vs. WT.