Effect Of Degree Of Initial Malformations Of Impacted Femoral Neck Fractures Under 65 Years Of Age On Femoral Neck Shortening

Objective:The purpose of this study was to analyze the relationship between the degree of shortening and initial deformity of impacted femoral neck(IFNFS)after hollow screw fixation in patients under 65 years of age and the effect of femoral neck shortening on function.Methods:Retrospective analysis of patients with impacted femoral neck fracture treated in the Department of Orthopaedics of the second Hospital of Shanxi Medical University from January 1,2013 to June 30,2017,Screening of 53 complete cases according to inclusion criteria and exclusion criteria.Among them,19 cases were male and 34 cases were female,and three hollow screws were used for internal fixation.The patients were followed up 12-24 months after treatment.Hip harris score(HHS)was used to evaluate the recovery of function.The posterior inclination angle,valgus angle,pauwels angle of the affected femoral head were measured.The last follow-up pelvic positive position X-ray were examined to calculate the percentage of joint-coarsal distance(ATD)decrease representing the degree of femoral neck shortening.Not less than 30% is significantly shortened(SFNS)and less than30% is not significantly shortened(NSFNS).Analysis of the related factors of necking and the effect on function.Results:All 53 patients healed without adverse events such as femoral head necrosis.Women had34 patients(64.15%)and 7 patients(13.2%)had significant necking.Test T independentsamples found that necking was associated with valgus angle(p<0.001),posterior dip angle(p=0.001)and BMI(p=0.001).Logistic regression analysis found that valgus angle was a significant predictor of necking(P=0.041).The hip harris score decreased with the increase of femoral neck contraction,and the HHS of SFNS group and NSFNS group were 82.57±5.12 and 94.15±4.03,respectively.Conclusion:The degree of valgus deformity is an independent risk factor for neck shortening in impacted femoral neck fractures,and femoral neck shortening is associated with hip function.