三维打印镜像模型在锁骨骨折微创内固定中的应用研究

Application of three dimensional printing mirror image model in minimally invasive internal fixation of clavicle fractures

背景:锁骨骨折的微创化手术治疗方式可采用克氏针辅助复位接骨板内固定,但对于粉碎性骨折难以达到良好复位,由于体外塑形很难达到满意程度,闭合接骨板插入及螺钉固定有时会存在一定风险,如何微创化操作的同时实现接骨板的准确塑形和安全固定是目前较受关注的问题。目的:运用3D打印技术实现锁骨骨折内固定治疗的微创化。方法:2015年12月至2016年12月对12例单侧锁骨骨折患者行接骨板内固定术,所有骨折锁骨仅显露表面而不剥离锁骨床,对于粉碎性锁骨骨折采用三段小切口,微创经皮接骨板固定技术(minimally invasive percutaneous plate osteosynthesis,MIPPO)操作以保护锁骨血运,3D打印健侧锁骨镜像模型及骨折模型,在两个模型距离胸锁关节1 cm、3 cm、5 cm处做横截面测量长短轴,并进行双侧对照,偏差<10%再进行镜像模型手术预演,在镜像模型表面描绘出骨折线并进行接骨板预弯、钻孔、固定等实际操作,记录每个螺钉的长度和位置,术中调节钻头伸出套筒的长度为模型相应钉道记录的螺钉长度,以防止钻入过深而损伤锁骨下血管,从而实现尽可能少的组织剥离和最优化的固定。结果:将锁骨胸骨端左右侧3个层面的长短轴数据汇总,成对样本共6组,成对样本的相关系数均>0.78,成对样本中PC1、PC3、PC5的LL-RL及LS-RS组进行配对样本t检验,左右两侧差异性无统计学意义(P>0.05),所有病例均采用微创操作固定,未出现血管损伤情况,术后复查X线显示内固定良好,螺钉长度合适,使用的接骨板及螺钉与术前预演一致。结论:通过3D打印健侧锁骨镜像模型与骨折模型,在无骨折区测量对比,对于偏差<10%的病例,在镜像模型上进行手术演练,获得预弯的接骨板与螺钉长度数据,可以直接用于实际手术中,从而实现MIPPO操作的目的。

Background： Minimally invasive surgical treatment of clavicle fractures can be achieved by plate internal fixation with the assistance of Kirschner wire. However, it is difficult to achieve satisfactory reduction for comminuted fractures through shaping in vitro and there is also a certain risk for closed plate insertion and screw fixation, therefore how to achieve accurate shaping and safe fixation of steel plate in minimally invasive operation becomes a hot concern. Objective：To achieve minimally invasive treatment of clavicle fractures by using 3D printing technique. Methods： Totally 12 patients with unilateral clavicle fracture underwent plate internal fixation from December 2015 to December 2016. All patients were explored to the surface of the clavicle without stripping the clavicle bed. For the comminuted clavicle fracture, three small incisions were made, minimally invasive percutaneous plate osteosynthesis（MIPPO） operation was conducted to protect the clavicle blood flow, contralateral clavicle mirror image model and fracture model were produced by 3D printing, the transverse sections were made at 1 cm, 3 cm, 5 cm away from the sternoclavicular joint with their long and short axes measured,and made bilateral comparison. As for the mirror image models with the deviation of bilateral comparison less than 10%,the surgery can be rehearsed, depicting the fracture line on the surface of the mirror image model, pre-bending, drilling and fixing steel plate, recording the length and position of each screw, recording the length of drill out of the sleeve as the length of corresponding nail to avoid drilling too deep and protect the subclavian vessels, so that to achieve minimal tissue dissection and optimal fixation. Results： The data of long and short axes of transverse sections in both clavicles were collected.There were 6 pairs of samples, and the correlation coefficients of paired samples were all greater than 0.78. For paired samples t test was conducted between LL-RL and LS-RS groups, and the difference between the left and right sides was not statistically significant（P〈0.05）. All patients underwent minimally invasive operation without vascular injury, and postoperative X-ray review showed that the internal fixation was good, the screws were of proper length, and the plate and screws were the same with those in preoperative rehearsal. Conclusions： Through 3D printing technique of producing both mirror image model of uninjured side and fracture model and contrastive measurements in non-fracture region, cases with the deviation less than 10% can receive surgery rehearsal on mirror image model to get the data of pre-bent plate and screw length which can be used in actual surgery to achieve MIPPO operation.