Analysis Of Related Factors With The Development Of Avascular Necrosis Of The Femoral Head After Non-displaced Femoral Neck Fracture Treated With Internal Fixation

Objective: To identify the related factors affecting the occurrence of avascular necrosis of the femoral head(NFH)after internal fixation of non-displaced femoral neck fracture by means of retrospectively medical records and imaging data analysis,therefore to provide clinical basis for orthopedic surgeons to optimize the treatment strategy of this type of fracture.Methods: By the form of outpatient follow-up and telephone follow-up,the data of patients with non-displaced femoral neck fracture treated with cannulated compression screw internal fixation in the third Hospital of Hebei Medical University from January 2007 to September 2017 were collected.Record the patient's sex,age,BMI index,time from injury to operation,number of cannulated compression screws implanted,underlying complications and other health indicators(including diabetes,cancer,heart disease,cerebral embolism,use of anticoagulants,smoking).All patients were divided into two groups according to the occurrence of ANFH.ROC curve was used to determine the optimal cut-off value of age and operation time of patients with femoral head necrosis.Sex,age,BMI index,time from injury to operation,number of cannulated compression screws implanted were entered into logistic regression analysis to determine the correlation between these factors and ANFH.Results: 506 cases met the inclusion criteria.53 patients developed ANFH during the follow-up period,and the incidence was 10.5%.The average diagnosis time of femoral head necrosis was 19.2 months.The cut-off points of ANFH patients' age and time from injury to operation were 69 years and 43 hours,respectively.Logistic regression analysis showed that gender(P = 0.097),BMI(P = 0.096),number of cannulated compression screws(P = 0.098),and time from injury to surgery(P = 0.207)were not risk factors for ANFH;however,Age ?69 years was a significant predictor of femoral head necrosis(OR 4.6;95% CI 1.1-17.9;P = 0.028).Conclusions: The patients aged 69 or younger with non-displaced femoral neck fractures have an increased risk of AHFH after percutaneous cannulated compression screw treatment.