Figure 4.

(a and b). Micrographs of representative cellular types in callus adjacent to the bone defect after 10 d. Apart from fibrozytes and fibroblasts (arrows), osteotomized animals accumulate large numbers of lymphocytes, granulocytes and multinucleated giant cells (arrowheads). In contrast, callus in fractured animals hardly contained any inflammatory cells (b). HE staining, magnification 200×.