Repeated transient ischemia during fracture healing：a micro-CT observation / 中国组织工程研究

ABSTRACT

BACKGROUND:Some studies have shown that blocking the venous return can promote fracture healing but there is no study about the effect of repeated transient ischemia on promoting fracture healing. OBJECTIVE:To observe the promoting effect of repeated transient ischemia on early fracture healing based on micro-CT technique. METHODS: Forty-eight Wistar rats were used to make animal models of right tibial midpiece closed fractures folowed by K-wire fixation. Rats were randomly divided into four groups 24-hour group, 48-hour group, 72-hour group and control group. Tourniquet was used on the root of the affected thigh, inflated for 10 minutes, and then released for 10 minutes. Three above-mentioned cycles were taken as an ischemic treatment. At 24 hours after fracture fixation, the ischemic treatment was first carried out, and after that, it was done every 24 hours in the 24-hour group, every 48 hours in the 48-hour group and every 72 hours in the 72-hour group. In the control group, the tourniquet with no inflation was used once on the right lower limb every 24 hours after fixation. Al the rats were kiled at 2 weeks after modeling to take out the right tibia with removal of K-wires for micro-CT observation. RESULTS AND CONCLUSION:The trabecular bone volume and total volume in the regions of interest were significantly higher in the 24-hour group than the other three groups (P 0.05). These findings indicate that within 2 weeks after fractures, the repeated transient ischemia can promote fracture healing, which may be related to the improvement in the secretion of growth factor, revascularization and osteoblast proliferation induced by repeated transient ischemia.