Bi-planar robot navigation for cannulated screw fixation in the treatment of femoral neck fractures

摘要

Objective To investigate the clinical results of Bi-plane robot navigation for cannulated screw fixation in the treatment of femoral neck fractures. Methods Between May 2011 and May 2015, 86 patients with femoral neck fracture who were fixed with cannulated screws were retrospectively analyzed. The patients were divided into navigation group and non-navigation group according to whether the Bi-planar robot used for navigation or not. The patients were matched concerning gender, age and Garden classification. A total of 64 patients were included in the study. In navigation group, there were 32 cases, including 10 males and 22 females. The average age was 59.4±5.6 yr (range, 51-68 yr). According to Garden classification, there were 1 case of type I, 7 cases of type II, 14 cases of type III and 10 cases of type IV. In non-navigation group, there were 32 cases, including 12 males and 20 females. The average age was 59.1±4.9 yr (range, 53-70 yr). According to Garden classification, there were 1 case of type I, 5 cases of type II, 18 cases of type III and 8 cases of type IV. Sixty-four cases were all fixed with cannulated screws. The fluoroscopy time, fluoroscopy times, drilling times, times of cannulated screw replacement, cannulated screw insertion time, blood loss, relative position between any two cannulated screws in postoperative AP view and lateral view, the angle between each cannulated screw and the femoral neck axis, fracture healing time and functional score were recorded. Results The parameters in navigation group versus non-navigation group were as follows: the average fluoroscopy time was 10.1±2.9 s vs 36.8±7.5 s, the average fluoroscopy times was 11.4±3.2 vs 43.9±11.0, the average drilling times was 3.9±1.1 vs 18.5±3.2, the average times of cannulated screw replacement was 0.4±0.6 vs 1.0±0.7; the average blood loss was 29.4±14.7 ml vs 50.2±17.1 ml, cannulated screws placement time averaged 28.8±7.3 min vs 43.8±7.9 min. The angle between any of two cannulated screws averaged 3.1°±1.1° vs 7.3°±1.2° in AP view and 2.9°±1.0° vs 4.4°±2.3° in lateral view, the angle between the cannulated screw and the femoral neck axis averaged 4.4°±1.6° vs 7.5°±1.7° in AP view and 4.9°±1.6° vs 8.0°±1.3° in lateral view. Significant differences were found concerning all above parameters between the two groups. Conclusion Bi-plane robot navigation technique helps more accurate cannulated screw fixation in the treatment of femoral neck fracture. This technique is less invasive. It decreases the time of screw insertion and reduces the radiation exposure. Key words: Robotics; Surgery, computer-assisted; Femoral neck fractures; Internal fixators