Fig. 4

Rapamycin inhibits HO recurrence after surgical resection in FOP-ACVR1 mice. a Schematic view of the experiments. △ indicates the day of the pinch-injury. ☆ indicates the day of the surgical resection. b Representative μCT images of the injured sites in each group.. Arrows indicate injury-induced HO, and arrowheads indicate recurrent HO. c Quantification of HO at the injured sites. The HO volume was measured from the μCT images of mice in the control (n = 5), surgery-initiated (n = 3) and early treatment (n = 7) groups. *, p < 0.05, **, p < 0.01, Student’s t-test. d Representative μCT images of HO in the contralateral limbs of mice in each group. Arrows indicate HO. e Volume of increased HO in the contralateral limbs. The volume of injury-induced HO (n = 2 for each group) in the contralateral limbs was measured before (Day 28) and after (Day 49) the surgical resection, and the volume change was calculated