A study on mRNA expressions of interleukin 10 during fracture healing for wound age determination.

We investigated mRNA expressions of interleukin 10 (IL-10) during fracture healing for wound age determination. Macroscopically, calluses were formed at 144 h post-injury, and thickening of the fracture edge was observed at 240 h post-injury. Slight infiltration of neutrophils and macrophages was detected at 3 h post-injury, and moderate infiltration of T and B lymphocytes was detected at 72 h post-injury. In addition, osteoblasts proliferated at 24 h post-injury. IL-10 mRNA increased immediately after the intervention and peaked at 24 h, and the expressions were detected in osteocytes before and after injury, and in osteoblasts at 3 h post-injury. Although the intensity was stable in osteocytes, that in osteoblasts was strongest at 24 h post-injury. Among inflammatory cells, the expressions were exclusively detected in macrophages. These results indicated that examinations of macroscopic and microscopic changes in fracture edges, and mRNA expressions of IL-10, would be informative for fracture healing and dating.