Abstract: Objective To retrospectively analyze the incidence and influencing factors of proximal femoral shortening after intertrochanteric fracture surgery. Methods The clinical data of 97 patients with intertrochanteric fracture treated from January 2017 to February 2020 were retrospectively analyzed.There were 31 cases with the dynamic hip screw(DHS),41 cases with the proximal femoral nail antirotation(PFNA),25 cases with Intertan.They were divided into normal group(59 cases) and PFS group(38 cases) according to the shortening of proximal femur after operation.The differences of age,gender,body mass index(BMI),bone mineral density,fracture type,internal fixation method,reduction quality,TAD value and complete weight-bearing time between the two groups were observed.Results In this group,the proportion of proximal femoral shortening was 38/97(39.18%).In PFS group,the shortening of femoral neck main screw was (5.43±1.72)mm,including 2 cases(2.06%) with internal fixation penetrating the femoral head and 5 cases(5.14%) with nonunion； The proportion of type Ⅲ and type Ⅳ fractures in the normal group was 40.68%,and that in the PFS group was 76.32%,the difference was statistically significant(P<0.05).The proportion of PFNA /Intertan was 76.27% in the normal group and 65.79% in the PFS group(P<0.05).There were 26 cases of positive reduction,18 cases of neutral support and 15 cases of negative support in the normal group,while there were 8 cases,13 cases and 17 cases in the PFS group,the difference was statistically significant(P<0.05).The complete weight-bearing time of normal group was (8.54±2.37)weeks,which was significantly later than that of PFS group(4.15±1.83)weeks(P<0.001).Conclusions  Internal fixation,reduction quality and complete weight-bearing time were important factors affecting the proximal femoral shortening after intertrochanteric fracture.

Key words: intertrochanteric fracture, internal fixation, proximal femoral shortening