Objective:To compare the efficacy of inverted triangular and equilateral triangular cannulated screw internal fixation (CSIF) in the treatment of femoral neck fracture (FNF) in young and middle-aged patients.Methods:A retrospective cohort study was conducted to analyze the clinical data of 52 patients with FNF admitted to Qingdao Central Hospital of Rehabilitation University from January 2020 to January 2022, including 18 males and 34 females, aged 28-60 years [(45.7±9.3)years]. Based on the Garden classification, the fractures were classified as type I in 11 patients, type II in 34, and type III in 7. According to Pauwels classification, the fractures were classified as type I in 33 patients, type II in 13, and type III in 6. Among them, 28 patients received inverted triangular CSIF (inverted triangle group) and 24 received equilateral triangular CSIF (equilateral triangle group). Before surgery and at 3 months after surgery, nuclear medicine three-phase bone scan and bone tomography imaging were performed to evaluate the proximal blood supply recovery in the fractured sites in the two groups. The Harris hip joint function scores before surgery, at 1 day, 3 months after surgery, and at the last follow-up, the posterior tilt angles of the femoral head before surgery and at 3 months after surgery, and the fracture nonunion rate and ischemic necrosis rate of the femoral head at the last follow-up were compared between the two groups.Results:All the patients were followed up for 18-30 months [(24.2±5.6)months]. Before surgery, the fracture of both groups showed extensive blood supply defects at the proximal end. At 3 months after surgery, the excellent and good rate of the proximal blood supply recovery in the inverted triangle group was 92.9% (26/28), significantly higher than 70.8% (17/24) in the equilateral triangle group ( P<0.05). The Harris hip joint function scores before surgery were (44.1±4.1)points and (43.5±5.1)points in the inverted triangle group and equilateral triangle group ( P>0.05). At 1 day, 3 months after surgery, and at the last follow-up, the Harris hip joint function scores in the inverted triangle group were (71.7±3.6)points, (87.0±3.6)points, and (88.7±2.6)points respectively, higher than those in the equilateral triangle group [(65.0±5.4)points, (80.5±5.2)points, and (82.6±4.0)points] ( P<0.05). In both groups, there were no significant differences between the Harris hip joint function scores at the last follow-up and those at 3 months after surgery ( P>0.05), which were all higher than those at 1 day after surgery ( P<0.05). The posterior tilt angles of the femoral head were (16.9±4.4)° and (16.8±5.0)° in the inverted triangle group and equilateral triangle group preoperatively ( P>0.05). At 3 months after surgery, the posterior tilt angles of the inverted femoral head were (8.9±1.9)° and (9.0±1.8)° in the inverted triangle group and equilateral triangle group ( P>0.05). The posterior tilt angles of the femoral head at 3 months after surgery were lower than those before surgery in both groups ( P<0.05). At the last follow-up, there were no statistically significant differences in the fracture nonunion rate and ischemic necrosis rate of the femoral head between the two groups ( P>0.05). Conclusion:Compared with equilateral triangle CSIF, inverted triangle CSIF achieves better recovery of the proximal blood supply and hip joint function in the treatment of femoral neck fracture in young and middle-aged patients.

Objective:To compare the efficacy of inverted triangular and equilateral triangular cannulated screw internal fixation (CSIF) in the treatment of femoral neck fracture (FNF) in young and middle-aged patients.Methods:A retrospective cohort study was conducted to analyze the clinical data of 52 patients with FNF admitted to Qingdao Central Hospital of Rehabilitation University from January 2020 to January 2022, including 18 males and 34 females, aged 28-60 years [(45.7±9.3)years]. Based on the Garden classification, the fractures were classified as type I in 11 patients, type II in 34, and type III in 7. According to Pauwels classification, the fractures were classified as type I in 33 patients, type II in 13, and type III in 6. Among them, 28 patients received inverted triangular CSIF (inverted triangle group) and 24 received equilateral triangular CSIF (equilateral triangle group). Before surgery and at 3 months after surgery, nuclear medicine three-phase bone scan and bone tomography imaging were performed to evaluate the proximal blood supply recovery in the fractured sites in the two groups. The Harris hip joint function scores before surgery, at 1 day, 3 months after surgery, and at the last follow-up, the posterior tilt angles of the femoral head before surgery and at 3 months after surgery, and the fracture nonunion rate and ischemic necrosis rate of the femoral head at the last follow-up were compared between the two groups.Results:All the patients were followed up for 18-30 months [(24.2±5.6)months]. Before surgery, the fracture of both groups showed extensive blood supply defects at the proximal end. At 3 months after surgery, the excellent and good rate of the proximal blood supply recovery in the inverted triangle group was 92.9% (26/28), significantly higher than 70.8% (17/24) in the equilateral triangle group ( P<0.05). The Harris hip joint function scores before surgery were (44.1±4.1)points and (43.5±5.1)points in the inverted triangle group and equilateral triangle group ( P>0.05). At 1 day, 3 months after surgery, and at the last follow-up, the Harris hip joint function scores in the inverted triangle group were (71.7±3.6)points, (87.0±3.6)points, and (88.7±2.6)points respectively, higher than those in the equilateral triangle group [(65.0±5.4)points, (80.5±5.2)points, and (82.6±4.0)points] ( P<0.05). In both groups, there were no significant differences between the Harris hip joint function scores at the last follow-up and those at 3 months after surgery ( P>0.05), which were all higher than those at 1 day after surgery ( P<0.05). The posterior tilt angles of the femoral head were (16.9±4.4)° and (16.8±5.0)° in the inverted triangle group and equilateral triangle group preoperatively ( P>0.05). At 3 months after surgery, the posterior tilt angles of the inverted femoral head were (8.9±1.9)° and (9.0±1.8)° in the inverted triangle group and equilateral triangle group ( P>0.05). The posterior tilt angles of the femoral head at 3 months after surgery were lower than those before surgery in both groups ( P<0.05). At the last follow-up, there were no statistically significant differences in the fracture nonunion rate and ischemic necrosis rate of the femoral head between the two groups ( P>0.05). Conclusion:Compared with equilateral triangle CSIF, inverted triangle CSIF achieves better recovery of the proximal blood supply and hip joint function in the treatment of femoral neck fracture in young and middle-aged patients.