Radiographic fracture features predicting failure of internal fixation of displaced femoral neck fractures.

INTRODUCTION: Fixation-related complications of displaced femoral neck fractures treated by internal fixation are accompanied by high mortality and morbidity. The aim of this study is to investigate the pre- and postoperative radiographic fracture characteristics in relation to patient age and the occurrence of reoperation caused by fixation failure.

METHODS: The preoperative radiographs of all patients presenting with a proximal femur fracture between January 2004 and December 2012 were retrospectively assessed for fracture type and dislocation (AP and lateral view). Patients with a displaced femoral neck fracture treated by closed reduction and internal fixation were included. The postoperative radiographs were assessed on adequate fracture reduction and correct position of the implant. Patient characteristics and outcome in terms of occurrence of fixation failure (implant breakout, non-union) and reoperation rate were recorded.

RESULTS: Hundred and-forty-nine patients were admitted with a displaced femoral neck fracture and treated by internal fixation. Fixation failure was seen in 34 (23%) patients; 9 patients suffered from osteonecrosis. In total, 37 (25%) patients underwent reoperation caused by fixation-related complications. Taking the different age categories into account, 44% of the patients >75 years suffered fixation failure compared with 17% of the patients <65 years. Postoperative incorrect reduction, with persisting dorsoventral dislocation and/or lack of medial support resulted in reoperation in 37% of the patients, compared to 19% reoperations in patients with adequate reduction.

CONCLUSION: The results of this study show that patient age and fracture reduction are important predictors for reoperation. In the preoperative treatment plan, patient age should be taken into account and surgeons should strive for anatomical reduction. Patients over 75 should always undergo arthroplasty. In patients aged 65-75, conversion to arthroplasty should be strongly considered if anatomical reduction is impossible.