Abstract
Introduction
It is well known that blood flow is a critical key component of fracture repair. Previously, we demonstrated that transcutaneous application of CO2 increased blood flow in the human body. To date, there has been no report investigating the effect of the carbonated therapy on fracture repair.
Hypothesis
We hypothesized that the transcutaneous application of CO2 to fracture site would accelerate fracture repair.
Materials & Methods
A closed femoral shaft fracture was produced in rats. Transcutaneous CO2 absorption enhancing hydrogel and CO2 adaptor that sealed the body surface and retained the gas inside were used for CO2 treatment. Rats without CO2 treatment served as control. Radiographic, biomechanical and histological analysis was performed to assess the fracture repair. Gene expression of chondrogenic, hypertrophic, osteogenic and angiogenic markers was measured by real-time PCR at 1, 2, 3, and 4 weeks post-fracture.
Results
Union rate, biomechanical properties, and gene expression of chondrogenic, hypertrophic, osteogenic and angiogenic markers was significantly higher in CO2 group compared to control group. Histological evaluation demonstrated that enchondral ossification was promoted in CO2 group.
Discussion & Conclusions
Our study indicate that transcutaneous application of CO2 accelerates fracture repair via acceleration of endochondral ossification and vascularization, and may become a novel and useful therapy for promoting fracture repair.