Comparison of Early Clinical Results for Femoral Neck System and Cannulated Screws in the Treatment of Unstable Femoral Neck Fractures

Objective To compare early clinical effects of the femoral neck system (FNS) and three cannulated screws for the treatment of patients with unstable femoral neck fractures. Methods A retrospective analysis with pair matching of 81 patients who received FNS or cannulated screw internal fixation for Pauwels type-3 femoral neck fracture in our hospital from January 2019 to December 2019 was conducted. Patients who received FNS were the test group, and those who received cannulated screws comprised the control group. Matching requirements were as follows: same sex, similar age, and similar body mass index (BMI). A total of 30 pairs were successfully matched at a 1:1 ratio, including 12 males and 18 females. The average age of the patients in the FNS group was 54.53 +/- 6.71 years. In the cannulated screw group, the average age of the patients was 53.14 +/- 7.19 years. The operation time, intraoperative blood loss, hospital stay, hospitalization cost, postoperative visual analog scale (VAS) score, time to walking without crutches, Harris score, femoral head necrosis rate, and complication rate were compared between the groups. Results Postoperative re-examination of radiographs showed satisfactory reduction in all patients, and all patients were followed up for 10-22 months. Those in the FNS group had lower postoperative VAS scores, earlier times to walking without crutches, higher Harris scores at the last follow-up, and lower complication rates (P < 0.05). VAS scores were lower in the FNS group (3.13 +/- 1.07 scores) than in the cannulated screw group (3.77 +/- 1.04 scores) (P = 0.018). Patients in the FNS group (5.23 +/- 1.33 months) recovered to walking without crutches earlier than did those in the cannulated screw group (6.03 +/- 1.45 months) (P<0.001). In addition, a statistically higher postoperative Harris score was detected in the FNS group (86.16 +/- 7.26) than in the cannulated screw group (82.37 +/- 7.52) (P = 0.039). Overall, a higher incidence of complications was observed in the cannulated screw group (9/30) than in the FNS group (2/30) (P = 0.042). However, intraoperative blood loss and hospitalization costs were greater in the FNS group (P < 0.05). Intraoperative blood loss was greater in the FNS group (99.73 +/- 4.69) than in the cannulated screw group (30.27 +/- 9.04) (P<0.001). In addition, patients in the FNS group (46976 +/- 2270 yen ) spent more on hospitalization costs than did those in the cannulated screw group (15626 +/- 1732 yen ) (P<0.001). No statistically significant difference in operation time, hospital stay, or femoral head necrosis rate was observed between the two groups (P > 0.05). Conclusion For patients with unstable femoral neck fractures, FNS has better clinical efficacy than cannulated screws, though it is also more expensive.