[COMPARATIVE STUDY ON FIXATION WITH PERCUTANEOUS CANNULATED SCREWS ASSISTED BY ROBOT NAVIGATION AND CONVENTIONAL SURGERY WITH MANUAL POSITIONING FOR FEMORAL NECK FRACTURES].

OBJECTIVE: To investigate the effectiveness and the advantage of fixation with percutaneous cannulated screws assisted by robot navigation in the treatment of femoral neck fractures by comparing with the conventional surgery. METHODS: Between January 2013 and December 2014, 20 patients with femoral neck fracture were treated by internal fixation with percutaneous cannulated screws assisted by robot navigation (navigation group), another 18 patients undergoing conventional surgery with manual positioning were chosen as the control group. There was no significant difference in gender, age, cause of injury, the injury side, time from injury to operation, and the classification of fractures between 2 groups (P > 0.05). The operation time, X-ray fluoroscopy time, blood loss, frequency of guide pin insertion, and healing time were recorded. At 1 week after operation, the parallel degree of screws was measured on the anteroposterior and lateral X-ray films; the Harris score was used to evaluate the hip function. RESULTS: All incisions of 2?groups healed by first intention after operation. There was no significant difference in operation time between 2?groups (t= -1.139, P=0.262). The blood loss, frequency of guide pin insertion, and X-ray fluoroscopy time of navigation group were significantly less than those of control group (P < 0.05). There were 2 screws penetrating into the joint cavity in control group. The patients were followed up 12-24 months with an average of 18 months. The navigation group got significantly better parallel degree of screws than control group on the anteroposterior and lateral X-ray films (t=25.021, P=0.000; t=18.659, P=0.000). Fractures healed in all patients of navigation group (100%), and the healing time was (21.8±2.8) weeks; fracture healed in 16 patients of control group (88.9%), and the healing time was (24.0 ± 3.7) weeks. There was no significant difference in healing rate and healing time between 2 groups (χ2=2.346, P=0.126; t=1.990, P=0.055). The Harris score of navigation group (87.1±3.7) was significantly higher than that of control group (79.3±4.7) at last follow-up (t= -5.689, P=0.000). CONCLUSIONS: Cannulated screw fixation assisted by robot navigation is a good method to treat femoral neck fractures, which has the advantages of more accurate positioning, better hip function recovery, less surgical trauma, and shorter X-ray exposure time.