股骨颈骨折空心钉内固定数字化模板的建立

Establishment of digital template of cannulated screw fixation for femoral neck fractures

背景:按照骨折治疗的AO原则,目前治疗股骨颈骨折的趋势是尽早切开关节囊,清除血肿,解剖复位,加强内固定,不必缝合关节囊,可降低股骨头缺血性坏死的发生率。股骨颈骨折空心钉的安放位置是维持稳定构型的关键,但置钉准确性受个体差异,置钉定位影像设备二维性及术者经验等主观因素影响较大,临床上急需一种实用性强花费较小且易于推广使用的辅助置钉方法。目的:构建骨颈骨折中空加压螺钉立体模型,通过3D生物打印技术精确建立导航模板并验证。方法:18例志愿者知情同意后,连续螺旋CT进行双侧股骨上端加密扫描。将Dicom数据导入Amira3.1(TGS)软件,三维重建骨折模型,导入Image-ware12.1软件,数字化设计最佳穿刺通道,三维重建股骨颈螺钉三维立体模型。提取解剖学形态,建立反向模板,3D生物打印实物模板,进行手术模拟验证。结果与结论:成功地建立了股骨颈三维模型及空心钉内固定模型,设计出了数字通道及螺钉最佳穿刺途径,制作出导航模板。模拟手术中置钉位置全部在最佳钉位。生成的三维模型与导航模板体外贴附良好,成功穿刺后断层证明穿刺通道位置较准确。提示成功构建了数字仿真股骨颈骨折内固定三维模型,逆向工程及3D生物打印导航模板技术能够提高手术操作精确性,为临床提供理论依据和技术支持。

BACKGROUND：In accordance with AO principles of fracture treatment, the tendency of femoral neck fracture is to cut open articular capsule, clean hematoma, carry out dissection and reduction, strengthen internal fixation, not necessary to suture articular capsule, resulting in decreasing the incidence of avascular necrosis. Cannulated screw placement for femoral neck fracture is a key to stabilize the structure. However, accuracy of nail placement is greatly affected by individual difference, two-dimensional imaging equipment for pedicle screw positioning and physician’s experiences. An assisted pedicle screw method that has strong practicability, low cost, and is easily spread to be used is urgently needed. OBJECTIVE：To construct three-dimensional models of femoral neck fractures with cannulated compression screw, to precisely establish navigation template using three-dimensional bio-printing technology and to verify. METHODS：After 18 volunteers signed informed consent. Continuous spiral CT was used to scan bilateral upper end of the femur via encryption. Dicom data were loaded into Amira 3.1 software for reconstructing three-dimensional fracture models, and then these data were loaded into Image-ware12.1 software. The best puncture channel was designed digital y. Three-dimensional models of femoral neck fractures with screw were reconstructed. Anatomic morphology was extracted, and reverse template was established. Physical template was printed with three-dimensional bio-printing technology, and verified by surgical simulation. RESULTS AND CONCLUSION：Three-dimensional models of femoral neck fractures and models of cannulated screw were successful y established. Digital channel and optimal puncture pathway were designed, and navigation template was made. Screw placement during surgical simulation was in the optimal position. Produced three-dimensional model wel adhered to navigation template in vitro. After successful puncture, fault verified that the position of puncture channel was exact. These findings indicated that three-dimensional models of digital simulated femoral neck fracture fixation were successful y established. Reverse engineering and three-dimensional bio-printing technology improve the accuracy of surgical procedures, and provide theoretical basis and technical support for the clinic.