3D打印人工椎体在胸腰椎肿瘤整块切除后重建中的应用

目的探讨3D打印人工椎体在胸腰椎肿瘤全脊椎整块切除术中应用的可行性。方法2016年12月至2019年9月对33例胸腰椎体恶性肿瘤患者采用后路全脊椎切除术治疗,男25例,女8例;年龄15~76岁,平均58.0岁。病变部位:胸椎29例,腰椎4例。累及节段:单节段30例,双节段2例,三节段1例。肿瘤类型:原发恶性肿瘤6例,转移性肿瘤27例。27例转移性肿瘤患者术前Tomita评分2~5分,平均3.9分;修正的Tokuhashi评分9~15分,平均11.1分。依据全脊椎切除术中重建方式不同,将33例胸腰椎体恶性肿瘤患者分为3D打印人工椎体重建组(21例,采用3D打印人工椎体进行前柱重建)和钛网重建组(12例,采用钛网植入同种异体骨进行重建)。主要观察指标为脊髓神经损害和疼痛恢复程度,肿瘤局部控制率及假体下沉发生率等。术后24 h、术后3个月疼痛视觉模拟评分(visual analogue scale,VAS)与术前比较采用配对设计t检验。结果全部病例随访3~31个月,平均10.9个月。3D打印人工椎体重建组术中出血量(3255.6±1981.9)ml(t=2.042,P>0.05)、手术时间(5.6±1.4)h(t=0.591,P>0.05)、术后引流量(655.6±223.6)ml(t=0.118,P>0.05)与钛网重建组的差异均无统计学意义。两组患者术前、术后24 h和3个月VAS评分的组间差异均无统计学意义(P>0.05);两组患者术后24 h和3个月均较术前明显改善,差异均有统计学意义(P<0.05)。33例患者中31例(97.0%)末次随访时Frankel分级有至少1个等级的改善。随访期间钛网重建组12例患者中5例(41.7%)影像学显示不同程度的下沉,而3D打印人工椎体重建组21例患者未出现假体下沉表现,两组下沉发生率的差异有统计学意义(χ^2=10.313,P=0.013)。结论3D打印技术制造的多孔钛人工椎体具有良好的生物相容性和机械稳定性,可以用于椎体切除后的重建。

Application of 3D printed porous artificial vertebra in reconstruction of thoracolumbar tumor

Objective To evaluate the clinical effectiveness of the reconstruction of the thoracic and lumbar spine using the 3D-printed vertebral body after total en bloc spondylectomy.Methods From December 2016 to September 2019,33 patients with spinal tumors were treated with total en bloc spondylectomy,including 25 males and 8 females with an average age of 58.0 years(range,15 to 76).The locations of the lesions contained:29 in the thoracic and 4 in the lumbar.The surgical segments includeda single vertebra in 30 cases,2 vertebrae in 2 cases,and 3 vertebrae in 1 case.The tumor type:the primary malignant tumor in 6 cases,the metastatic tumor in 27 cases.The preoperative Tomita score was 2-5 points(mean 3.9 points),while Tokuhashi score was 9-15 points(average 11.1 points).Divided into two groups according to different reconstruction methods during total spinal resection,33 patients with thoracolumbar vertebral body malignant tumors were divided into 3D printed artificial vertebral body reconstruction group(21 patients,3D printed artificial vertebral body was used for anterior column reconstruction)and titanium Mesh reconstruction group(12 cases,titanium mesh implanted with allograft bone was used for reconstruction).The main observation indicators included the degree of spinal nerve damage and pain recovery,the local tumor control rate,and the incidence of prosthesis sinking.The visual analogue scale(VAS)at 24 hours and 3 months after operation was compared with that before operation using paired design t test.Results All cases were followed up for 3 to 31 months.There was no statistically significant difference in intraoperative blood loss(t=2.042,P>0.05),surgical time(t=0.591,P>0.05),and postoperative drainage(t=0.118,P>0.05)between the two groups.The visual analogue scale(VAS)between the two groups at preoperative,24 hours and 3 months after operation was not statistically different(P<0.05).The Frankel grading of 31 patients(97.0%)had at least one grade improvement 3 months after operation.During the follow-up period,12 patients(41.7%)who underwent reconstruction with titanium mesh showed different degrees of subsidence in imaging,and 21 patients who used 3D printed artificial vertebral reconstruction did not exhibit prosthetic deposition.Chi-square test results of postoperative sink rate of the two methods was statistically different(χ^2=10.313,P=0.013).Conclusion This preliminary report suggests the 3D-printed vertebral body has good biocompatibility and mechanical stability,which can be used for reconstruction after total en bloc spondylectomy.