EFFECT OF FRACTURE FIXATION ON CORTICAL BONE BLOOD-FLOW

Because internal and external fixation devices alter blood flow, and thus the transport of nutrients to the cortical bone of a healing fracture, we studied the effects of a fluted intrameduilary rod (IMR), a half‐frame external fixator (EF), and a compression plate (PL) on the cortical bone directly adjacent to the fracture site at 4 and 48 h and 14 and 90 days after fixation. Three specific areas of cortical bone were studied: endosteal cortex, periosteal cortex, and subplate cortex (cortical bone under the compression plate). The fractures fixed with IMR had the lowest blood flow at all time periods studied. At 4 h, the difference between IMR and PL or EF was statistically significant in the endosteal cortex (p < 0.01 or p < 0.05, respectively); also, the difference between the IMR and EF in the subplate cortical bone region was significant (p < 0.05). At 14 days, the blood flow to the endosteal cortex was still significantly lower with IMR than with EF (p < 0.025). At 90 days, the blood flow to the subplate region of cortical bone was significantly (p < 0.02) higher with PL than with IMR but there was no significant difference in bone remodeling with the different fixation devices. Copyright © 1990 Orthopaedic Research Society