Analysis of influencing factors related to femoral head necrosis after closed reduction and internal fixation with hollow screws

Objective To retrospectively study the influencing factors of femoral head necrosis after treatment of femoral neck fractures with closed reduction and internal fixation with compressive hollow screws. Methods A total of 247 patients with complete clinical data out of 293 patients with femoral neck fractures treated by closed reduction and internal fixation with compressive hollow screws from January 2009 to March 2017 were included in the study. Multiple correlation factors were analyzed by SPSS 20.0 statistic system. Logistic multiple regression method was used to analyse the influencing factors of femoral head necrosis. Results All the 247 patients obtained a mean follow-up of 58 months (24 to 80 months). Femoral head necrosis occurred in 32cases (12.9%). The total average Harris score for this series was 81.4±3.9 points (54 to 98). Factors that might have an impact on necrosis of femoral head were ranked in the following likelihood sequence: quality of reduction (OR=9.854, P=0.012), arrangement of hollow screws (OR=7.965, P=0.017), fracture type (OR=6.453, P=0.021), screw removal or not (OR=5.364, P=0.027), preoperative traction (OR=2.561, P=0.042). Conclusion Quality of reduction is the most important factor that influences the prognosis. Triangle configuration of hollow screws, screws removal and no timely traction can increase the incidence of necrosis. Key words: Femoral neck fracture; Femoral head necrosis; Bone screws; Fracture fixation, internal; nfluencing factors