Comparison Of Efficacy Between Fully-threaded Cannulated Screws And Partially-threaded Cannulated Screws In Treatment Of Femoral Neck Fractures

Objective: To compare the clinical efficacy of fully-threaded cannulated screws(FTCS)and partially-threaded cannulated screws(PTCS)by performing a retrospective study of femoral neck fractures treated with cannulated screws,and analyze the relationship between fracture prognosis and fracture classification,quality of reduction,etc.To provide reference for the treatment of femoral neck fractures.Methods: 183 femoral neck fractures cases treated with cannulated screws in our hospital between January 1,2016 and December 31,2017 were retrospectively analyzed.Among them,there were 79 cases treated with fully-threaded cannulated screws(FTCS Group)and 104 cases treated with partially threaded cannulated screws(PTCS Group).All patients were followed-up for at least one year after surgery.Patients' general information including gender,age,fracture side,fracture classification,reduction quality,length of hospital stay,intraoperative bleeding volume,operation time was collected.The incidence of re-operations and fracture complications including nonunion,osteonecrosis of the femoral head(ONFH),internal fixation failure,femoral neck shortening between FTCS group and PTCS group were compared.And the effects of fracture classification and reduction quality on fracture healing were analyzed.Results: All patients were followed-up for 12-38 months,with an average of 17.8±5.96 months.FTCS group included 79 cases,50 were males and 29 were females,with an average age of 48.0±12.67 years old.PTCS group included 104 cases,52 were male and 52 were female,with an average age of 50.7±14.81 years old.There was no significant difference in the general information between the two groups(P>0.05).There were no significant differences in average operation time,average intraoperative bleeding volume,overall complication rate,ONFH rate,internal fixation failure rate,and re-operation rate between the two groups(P>0.05).The femoral neck shortening rate in FTCS group(13.9%)was significantly lower than that in PTCS group(27.9%),the nonunion rate in FTCS group(17.7%)was significantly higher than that in PTCS group(7.7%)(P<0.05).Pauwels type ? fractures,Garden type ??? fractures and poor reduction quality would significantly increase the incidence of nonunion,internal fixation failure and re-operation(P<0.05),and the ONFH rate in Garden type ??? fractures was also higher than that in Garden type ? ?? fractures(P=0.027).Conclusion: Internal fixation with FTCS and PTCS could achieve good clinical results in the treatment of femoral neck fractures.Compared with PTCS,FTCS could reduce the shortening of femoral neck,but had a higher rate of nonunion.Fracture classification and reduction quality had significant influence on the prognosis of fracture.In addition to reasonable selection of screw type,it is necessary to pay attention to fracture classification and good reduction to achieve better treatment effect.