Résumé
Objective To find out factors related to avascular necrosis (AVN) of femoral head through a retrospective study of patients with femoral neck fractures treated with cannulated screws.Methods Two hundred and thirty cases of femoral neck fracture whn had been treated with cannulated screws in our department from August 1994 to October 2003 were analyzed statistically.Six factors of patient,age,gender,fracture type (Garden clas- sification),reduction method (close or open),the quality of reduction (Garden Index) and time interval from injury to surgery were analyzed statistically with rank sum test and logistic multiple regression.Results Factors that might have an impact on avascular necrosis of femoral head were ranked in the following likelihood sequence: fracture type,quality of reduction,reduction method,time interval from injury to surgery and age.Gender was found to have little impact on the prognosis of femoral neck fracture (P＞0.05).Conclusions Fracture displacement is the most critical factor that influences the prognosis.Anatomical reduction (close or open) must be achieved to re- duce the risk of AVN.Timing of surgery shows its importance.High age will not lead to an increased incidence of AVN.
Résumé
Objective To determine if nitric oxide(NO)is involved in the protective effect of propefolpretreatment(PP)against ischemia-reperfusion injury(I/R).Methods Eighteen male SD rats weighing 250-350 gwere randomly divided into 3 groups(n=6 each):A normal control;B I/R and C PP+I/R.The animals werekilled by a knock on the head.Hearts were immediately removed and passively perfused in a Langendorff apparatusat 37℃ with oxygenated(95% O_2,5% CO_2)Krebs-Hensleit(KH)solution at 90 cm H_20.In group B and C thehearts were subjected to 35 min global ischemia by suspension of perfusion followed by 120 min reperfusion.Ingroup C the hearts were perfused with KH solution containing 50 ?mol?L~(-1) propofol for 10 min followed by 10 minpropefol wash-out before I/R.At the end of reperfusion myocardial specimen was obtained from left ventricle andhomogenized for determination of the activities of total NOS(iNOS+cNOS)aand SOD and expression of iNOS andheme-oxygenase-1(HO-1)and content of NO,The relationship between the NO content and activity and/orexpression of these protein and enzyme were analyzed by correlation analysis.Myocardium was examined with lightand electron microscope.Results The myocardial NO content,tNOS activity and tSOD activity were significantlylower in group B than in group A and C and there was no significant difference in NO content,and activity of tNOSand tSOD between group A and C.The NO content was positively correlated with tNOS and negatively correlatedwith Mn-SOD aetivety and HO-1 expression.Microscopic examination showed severe cell injury or necrosis in groupB but little injury in group C.Conclusion Ischemia and reperfusion decrease activity of tNOS and SOD butincrease HO-1 expression resulting in decrease in NO content.Propofol pretreatment protects the heart from I/Rinjury through increase in NOS and antioxidases(Mn-SOD,HO-1).