Analysis of Affecting Factors of Fixation Failure of Femoral Neck Fractures Using Internal Fixation

ABSTRACT

PURPOSE: To evaluate the factors which influence on the fixation failure after internal fixation using multiple cannulated screws in the patients with femoral neck fracture. MATERIALS AND METHODS: Ninty-six patients (male 63, female 33) who underwent closed reduction and internal fixation of femoral neck fracture between Feb. 1994 and Jun. 2002 with use of multiple cannulated screws. The mean age was 68 years (17~90) and mean follow-up period was average 50 months (36 months~6 years). The fixation failure was defined by change in fracture position above 10 mm, change in each screws position above 5%, backing above 20 mm, or perforation of the head, respectively. They were evaluated with the age, gender, fracture type, accuracy of reduction, placement of screws, posterior comminution and also studied the risk factors which influenced nonunion and the development of avascular necrosis. RESULTS: Twenty-four patients out of 96 patients had radiographic signs of fixation failure. The incidence of nonunion in the fixation failure group was 41% (10/24) and AVN was 33% (8/24). There were statistically significant correlations between fixation failure and nonunion and that posterior comminution, poor reduction and improper placement of the screws were the major factors contributing to nonunion. CONCLUSION: In case of femoral neck fracture of internal fixation using multiple cannulated screws, posterior comminution, poor reduction and improper placement of the screws were the major factors contributing to nonunion and fixation failure.