Fig. 4

Histological evaluation of cartilage injury and its association with the numbers and areas of colonies. A Representative images of tibial cartilage stained with safranin O/fast green. B OARSI score (n = 6). *p < 0.05 by the Mann–Whitney U test between the sham and pMx groups (black asterisks). *p < 0.05 by Kruskal–Wallis/Steel tests between the intact and pMx groups (orange asterisks). C Scatterplot of OARSI scores and colony numbers or colony areas. The p values were calculated using Spearman’s rank correlation and adjusted using Bonferroni’s correction method