Analysis Of Influencing Factors Of Proximal Femoral Nail Anti Rotation Screw Thread Piercing Through Femoral Head

Objective:Objective to study and analyze the influencing factors of spiral blade penetration through femoral head after PFNA operation for intertrochanteric fracture of femur,and to explore related preventive measures.Method:The data of 179 cases of intertrochanteric fracture of femur in the Department of orthopedics of the Second Affiliated Hospital of Nanchang University from September 2015 to March 2018 were analyzed retrospectively,including 94 males and 85 females,with an average age of 77.5 years(60~95 years old),in the Department of orthopedics,the Second Affiliated Hospital of Nanchang University.On the basis of the follow-up examination,the spiral blade was examined to penetrate the femoral head and divided into the successful group and the puncture group.The age,sex,the type of Evans fracture,the combination of the basic disease,the Singh index of the osteoporosis,the waiting time before the operation,the fracture reduction,the spires,the time of the ground weight were taken as a result.In the independent variable,the factors were analyzed by single factor,and the statistical single factor was analyzed in the multi factor Logistic regression to determine the significant factors(P < 0.05).Result:179 patients were followed up for an average of 6 months(3~9 months).8patients were found to have a screw blade piercing through the femoral head.The incidence rate was about 4.47%.Single factor analysis showed that the difference of basic disease,Singh index of osteoporosis,TAD,reduction degree of fracture,time of ground weight loss and type of fracture were statistically significant.Further analysis of these meaningful factors into the multi factor Logistic stepwise regression model shows that there is a significant difference between the fracture type,the Singh index of osteoporosis,the degree of fracture reduction,the time of TAD and the weight loss of the ground,which are the main factors affecting the penetration of the spiral blade.Conclusion:The major factors affecting the spiral blade to penetrate the femoral head are the more severe fracture(type III and IV type),the spires greater than 25 mm,the heavier the osteoporosis(below 3),the earlier the ground weight loss time and the lower the fracture reduction.In the clinical treatment,we should pay attention to this.Before the operation,we should make the best plan according to the patient’s specific situation,make full preparation before operation,and give effective preventive measures to further reduce the incidence of through.