Treatment Of Femoral Neck Fracture With Cannulated Internal Fixation Risk Factors For Reoperation

Objective: The purpose of this study is to estimate the incidence of reoperation and the risk factors of reoperation within 12 months following osteosynthesis with use of cannulated screws in parallel for femoral neck fracture.Methods: One hundred and ninety-four patients with femoral neck fracture hospitalized in the first affiliated of Dalian medical university from June 2010 to June2018 were retrospectively studied,all of them were older than 50 yesls old.All patients suffered from low energy injury.All patients underwent three cannulated screws in parallel with inverted triangle distribution for the treatment of femoral neck fractures.The X-ray films and follow-up data can be consulted through Jiahe system and radiology department of our hospital.Data included patient age,gender,fracture classification,hip Harris score.The fracture displacement was measured on preoperative X-ray films.The reduction of fracture,distance between the implant and the cortex of femoral neck,distance from tip of implant to cartilage of femoral head,angle between implant and lateral cortex of femoral shaft,and femoral neck shortening were measured on postoperative radiographs.The effects of the included variables on the risk of reoperation were evaluated using T-test?Chi-square test and logistic regression analysis.Results: The average age of 194 patients was 66 years(50-94 years).There were 121 female patients(62%)and 73 male patients(38%).Within one year,14 patients underwent reoperation,including 10 female patients(8.3%)and 4 male patients(5.4%).Twelve patients died.Patients younger than 70 years old were more likely to undergo reoperation(6.9% vs.7.5%)than patients older than 70.Among the variables related to fracture healing,displacd fracture,hip Harris score and unsatisfactory fracture reduction,the angle between the implant and the lateral cortex of femoral shaft is less than 127 degrees increase the risk of reoperation.The distance between the implant and the posterior cortex of the femoral neck,the subcortex of the femoralneck,the distance between the tip of the implant and the cartilage of the femoral head and the shortening of the femoral neck had no significant effect on the reoperation.The degree of femoral neck shortening is not significantly correlated with age and gender.Conclusions: Fracture displacement degree,hip Harris score,incomplete reduction of fracture,angle between implant and lateral cortex of femoral shaft are risk factors for reoperation.A good fracture reduction is perhaps more important than focusing on an optimal position of the implants.