Fig. 3

Differences of collagen staining results among the groups. a Immunohistochemistry staining (× 10) of type I collagen with magnifying details showed that the distribution was more uniform in the FNF group and striature result can be seen clearly. The distribution in the OA and ONFH group was less uniform. Striature result can also be seen in the OA group, but can hardly be seen in the ONFH group. Bar = 100 μm. b Masson’s trichrome staining (× 4) showed the blue-stained collagen fibers covered most area of the trabecular bone and striature result can be seen clearly in the FNF group. Positively stained collagen fibers in the OA group were less seen and they were sporadic in the ONFH group. Striature result can be found in the OA group, but can hardly be seen in the ONFH group. c Quantitative results showed the percentage of type I collagen in immunohistochemical staining among the groups. d Quantitative results showed the percentage of collagen fibers in Masson’s trichrome staining among the groups. Data were expressed as mean ± SD; N = 10 specimens/group. Bar = 100 μm. *p < 0.05 versus FNF group, #p < 0.05 versus OA group (by one-way ANOVA and Tukey’s post hoc test)