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). Conclusion 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.
ObjectiveTo evaluate the effectiveness of very low profile/variable angle locking plate (VLP) internal fixation for posterior Pilon fractures extending to the medial malleolus by posteromedial approach. MethodsA retrospective analysis was made on the clinical data from 13 patients with posterior Pilon fractures extending to the medial malleolus between December 2011 and August 2012. There were 4 males and 9 females with an average age of 48.9 years (range, 23-68 years). Fractures were caused by falling in 9 cases and by traffic accident in 4 cases. The locations were the left ankle in 6 cases and the right ankle in 7 cases. According to the Orthopedic Trauma Association (OTA) classification, 6 cases were rated as type 43B1, 4 cases as type 43B2, and 3 cases as type 43B3. Twelve cases had fibular fractures, including 11 cases of Denis-Weber type B, 1 case of Denis-Weber type C. The interval of injury and operation was 7-14 days (mean, 11.4 days). Open reduction was performed and VLP internal fixation was used for posterior malleolar fracture by posteromedial approach. ResultsPrimary healing of incision was obtained in all patients. Tibial nerve palsy was observed in 2 cases, and was cured after oral administration of mecobalamin. Twelve cases were followed up 12-18 months (mean, 14.5 months). According to the Burwell-Charnley's radiological evaluation system, 11 cases achieved anatomical reduction, 1 case achieved fair reduction. The fracture union time was 3-6 months (mean, 3.7 months). No loosening or breakage of internal fixation occurred during follow-up. According to the American Orthopaedic Foot and Ankle Society (AOFAS) ankle-hindfoot scale, the results were excellent in 7 cases, good in 4, and fair in 1; the excellent and good rate was 91.7%. ConclusionVLP internal fixation for posterior Pilon fractures extending to the medial malleolus by posteromedial approach can achieve good short-term effectiveness. The high quality of reduction is acquired under direct vision with low rate of soft tissue complications.