Figure 4.

Normal fracture healing in COX-1^–/– mice. Histologic sections were obtained from tibial fractures of adult wild-type (a) and COX-1^–/– (b) mice (n = 5) on day 21 after fracture and stained with Alcian blue/hematoxylin as described in Methods. Quantification of the tissue compositions (c) and osteoclast numbers (d) are presented as described in Figure 3. No significant differences were observed.