Study of the promoting effects of brief ischemic on fracture healing / 国际外科学杂志

ABSTRACT

Objective To explore the influence of brief ischemic on fracture healing.Methods Two hundred and forty wistar rats (weight was 200 g and half male) were made the right tibial midpiece closed fracture model.1.0 mm K-wires were used to fix the fractures.Rats were divided into 4 groups.Group A was 24 hours,group B was 48 hours,group C was 72 hours,and group D was the control group.Tourniquet was used on the root of the thigh of right lower limb.Tourniquet was inflated 10 min,then released 10 min,and repeated 3 times to make the brief ischemic model.48 rats were made brief ischemic at 24 hours after the fracture fixed.Then group A was at every 24 hours,group B was at every 48 hours,and group C was at every 72 hours made brief ischemic.Group D at every 24 hours after the fracture fixed was used tourniquet on the root of thigh of right lower limb each time 1 hour,but the tourniquet was not inflated.Group A,B,and C were made brief ischemic 5 weeks.Group D was tourniquet treated 5 weeks.Group A and D at 1 day,3 days,5 days,and 7 days after fracture fixed were detected the serum VEGF.All groups of rats were X-ray examinated and detected of serum VEGF at every two weeks after the fracture fixed.Every two weeks,every group randomly selected 12 rats to do immunohistochemical staining.We used the Image Pro Plus software to quantitative compare the IGF-2 positive cells in the fracture area.Results X-ray results were used three points method for analyzing.The scores of group A,B,and C were significantly higher than group D at 2 weeks,4 weeks,6 weeks after fracture fixed (P ＜ 0.05).The scores between group A,B,and C were no significant statistical difference at 2 weeks,4 weeks,6 weeks after fracture fixed (P ＞ 0.05).The levels of serum VEGF of group A were significantly higher than group D at 3days,5days,and 7 days after fracture fixed (P ＜ 0.05).The levels of serum VEGF of group B and C were obviously higher than group A and D at 2 weeks (P ＜ 0.05),and there was no obvious difference between group B and C (P =0.79,P =0.90,P =0.88).The same result was found between group A and D (P =0.94,P =0.551,P =0.53).There were no significant difference between four groups on the levels of serum VEGF at 8 weeks (P =0.66).Immunohistochemical results were that group B,group C VEGF positive cells were significantly higher than group A and group D at 2 weeks,4 weeks,6 weeks (P ＜0.05).There was no significant difference in group B and group C (P =0.19,P =0.10,P =0.38),or group A and group D (P =0.07,P =0.17,P =0.18).There was no significantly different in four groups at 8 weeks (P =0.08).Conclusions Brief ischemic can promote the healing of fracture and stimulate the expression of VEGF.The mechanism may be related to the signal channels of VEGF and other biological factors.This study will give new idea to clinic for promoting fracture healing.