ABSTRACT
【Objective】 To establish a digital model of lumbar 4 and lumbar 5 vertebral bodies through three-dimensional imaging technology so as to explore the precise placement of pedicle screws during the lumbar posterior internal fixation operation. 【Methods】 CT scan image data set of lumbar spine included six specimens. Then lumbar modeling was produced using Mimics software， implanting pedicle screws was simulated with the computer to determine the reliability of pedicle screw for herringbone crest method， Weinstein method， and Magerl method. 【Results】 This study included six specimens （4 males and 2 females）， with an average age of 42.83 years. The distance from the right Magerl entry point to the actual entry point of the lumbar 4 vertebrae was significantly greater than that of the left side. The distance from the left herringbone crest entry point of lumbar 4 vertebrae to the actual entry point was significantly greater than Weinstein method and Magerl method （PMagerl abduction angle > Weinstein abduction angle > herringbone abduction angle. The distances of true-Weinstein and true-herringbone ridges on the left side of lumbar 5 vertebrae were significantly greater than those on the right side （P=0.002 and P=0.004）， and the Weinstein abduction angle on the right side of lumbar 5 vertebrae was greater than that on the left side （P=0.003）. For the left and right sides of lumbar 5 vertebrae， the distance from herringbone crest entry point to the actual entry point was significantly greater than that of Weinstein method and Magerl method （P Magerl abduction angle > Weinstein abduction angle > herringbone abduction angle. 【Conclusion】 Both Weinstein entry point and Magerl entry point for lumbar 4 and lumbar 5 vertebra are close to the real entry point. The Weinstein abduction angle and Magerl abduction angle of lumbar 4 and lumbar 5 vertebrae have minor differences compared with real abduction angle. Therefore， it is recommended that Weinstein method is the preferred choice for lumbar 4 pedicle screw placement， while Weinstein method or Magerl method is the preferred choice for lumbar 5 pedicle screw placement.
ABSTRACT
BACKGROUND: The current internal fixation surgery for scapula fractures is limited by the complex anatomical structure of scapula, which is often difficult to operate, with much bleeding and time-consuming. OBJECTIVE: To observe the clinical efficacy of the application of 3D printing technology in scapula fracture surgery. METHODS: The clinical data of 28 cases (aged 34-70 years) with scapula fractures in the Second Affiliated Hospital of Nanjing Medical University from January 2016 to December 2018 were analyzed retrospectively. Among them, 14 cases were treated after routine preparation (control group). Another 14 patients underwent 64-slice thin-slice CT scanning and 3D reconstruction. The fracture model was printed with 3D printing technology. The surgical approach was designed and the internal fixation was customized before the operation (3D printing group). The operation time, intraoperative blood loss and intraoperative X-ray frequency of the two groups were recorded. Imaging data were followed up six weeks after the operation. The treatment effects were evaluated according to the Hardegger shoulder joint function assessment standard. All patients signed the informed consent. This study was approved by the Hospital Ethics Committee. RESULTS AND CONCLUSION: (1) All the 28 operations were successfully completed. The operation time, intraoperative blood loss and X-ray frequency of the 3D printing group were all less than those of the control group (P < 0.05). (2) The excellent and good rate of the 3D printing group was higher than that of the control group (P < 0.05). (3) The operative approach and internal fixation used in the 3D printing group were consistent with the preoperative design. The application of 3D printing technology in the surgical treatment of scapula fractures can help surgeons better understand the characteristics of scapula fractures and make surgical plans, reduce the difficulty of surgery, obtain more accurate reduction, reduce the duration of surgery, intraoperative bleeding and intraoperative X-ray fluoroscopy, and improve the surgical efficacy.
ABSTRACT
ObjectiveTo study the application of three-dimensional simulated surgical technique in precise hepatectomy. MethodsFrom July 2009 to February 2010, 16 patients with primary liver cancer underwent preoperative simulated imaging and three-dimensional simulation of liver resection.The 3D extent of simulated hepatectomy and actual hepatectomy was compared and analyzed. ResultsThe shape and the extent of the liver resected were very similar in the simulated and the actual hepatectomies. The mean differences in the length, breadth and depth of the remnant livers were 0. 6118 cm,0. 4490 cm and 0. 3199 cm, respectively. ConclusionsSimulation hepatectomy could predict the extent of the actual liver resection, and provided accurate guidance and preoperative planning for precise hepatectomy.