[Clinical efficacy of femoral neck screw system combined with supported hollow screw in treatment of femoral neck fractures with posterometral comminution in young and middle-aged patients].

To investigate the clinical efficacy of dynamic cross screw system (FNS) for femoral neck fractures in young and middle-aged patients with posterior medial comminution. A retrospective cohort study. Clinical data of 197 young and middle-aged patients with femoral neck fractures accompanied by posterior medial comminution treated with closed reduction FNS and internal fixation with anti-rotation cannulated screws in Beijing Luhe Hospital, Beijing Jishuitan Hospital and Beijing Tongren Hospital from October 2019 to October 2021 were analyzed retrospectively. According to different surgical methods, the patients were divided into two groups. There were 102 patients in the FNS group, included 55 males and 47 females with a mean age of (40.49±19.79) years; and there were 95 patients in the FNS plus anti-rotation hollow screw group (combined group), included 51 males and 44 females with an average age of (40.03±18.82) years. All patients were followed-up for at least 1 year after surgery. The general clinical data, surgical conditions and Harris score of the hip joint at the last follow-up of the two groups were compared. And the clinical efficacy of the two surgical schemes were evaluated and compared. After surgery, routine X-ray and CT examinations were performed to evaluate the fracture reduction and internal fixation, and the shortening of the femoral neck on the affected side was compared to that of healthy side according to the Zlowodzki method. At the last follow-up, the incidence of fracture reduction loss, screw resection and coxa vara in the combined group were all significantly lower than those in the FNS group [10 (10.5%) vs 28 (27.4%), 1 (1.0%) vs 7 (6.8%) and 9 (9.4%) vs 21 (20.5%), respectively, all <0.05]. The incidence of nonunion and necrosis of the femoral head in the combined group were both lower than those in the FNS group, but there was no significant difference between two groups (both >0.05). The postoperative mild, moderate and severe femoral neck shortening in the combined group were all lower than those in the FNS group, and the difference were not statistically significant (all >0.05). At the last follow-up, the Harris score in the combined group was 84.60±2.08, and it was higher than that in the FNS group (79.57±4.31), but the difference was not statistically significant (=0.403). FNS plus supporting hollow screw has a good clinical effect on femoral neck fractures in young and middle-aged adults with posterior medial comminution.