3D打印骨骼模型在经皮内镜下腰椎间盘摘除术中的临床应用

目的 探讨3D打印骨骼模型在经皮内镜下腰椎间盘摘除术(PELD)中的临床应用价值。方法 回顾性分析2016年7月—2017年10月苏州大学附属第三医院脊柱外科收治的62例腰椎间盘突出症患者的临床资料。其中男34例,女28例;年龄32～67岁,平均52.3岁。病变节段均为L_4/5节段,其中旁中央型椎间盘突出18例,侧方型椎间盘突出40例,极外侧型椎间盘突出4例;合并侧隐窝狭窄8例。采用WSPS V1.0医学影像处理软件处理影像学检查数据,生成3D打印机可识别的GCODE格式文件。使用聚乳酸材料,用3D打印机打印出完整的病变节段腰椎骨骼模型。依据病变部位将两侧椎间孔分为患侧组与健侧组,在骨骼模型上确定“5点2线”解剖标志,测量椎间孔的“3距1角”(椎间孔宽度、椎间盘后缘高度、椎间孔高度以及上关节突腹侧倾斜角)。患侧均行经皮椎间孔入路内窥镜下腰椎间盘髓核摘除术,并根据术中是否行椎间孔成形术,将患侧组椎间孔又分为成形组与未成形组。比较骨骼模型患侧组与健侧组椎间孔的3距1角,以及成形组与未成形组患者患侧椎间孔的3距1角。结果 62例打印模型中,患侧组椎间孔宽度、椎间盘后缘高度、椎间孔高度以及上关节突腹侧倾斜角分别为(6.30±1.71)mm、(4.88±1.63)mm、(21.07±3.78)mm、16.28°±1.13°,健侧组分别为(7.27±1.86)mm、(5.31±1.71)mm、(18.57±3.34)mm、25.72°±1.03°;患侧组椎间孔宽度、上关节突腹侧倾斜角均小于健侧组,差异均有统计学意义(t=2.133、2.877,P值均＜0.05),而椎间盘后缘高度、椎间孔高度两组之间差异均无统计学意义(P值均＞0.05)。62例患者均顺利完成手术,术中未行椎间孔成形38例,行椎间孔成形24例。成形组患侧椎间孔宽度、椎间盘后缘高度、椎间孔高度以及上关节突腹侧倾斜角分别为(4.77±0.83)mm、(4.97±1.35)mm、(16.23±2.02)mm、11.50°±2.15°,未成形组分别为(7.42±1.24)mm、(5.19±1.88)mm、(16.63±1.94)mm、22.22°±4.28°。成形组的椎间孔宽度及上关节突腹侧倾斜角均小于未成形组,差异均有统计学意义(t=6.681、8.001,P值均＜0.05);而椎间盘后缘高度、椎间孔高度两组之间差异均无统计学意义(P值均＞0.05)。结论 采用3D打印骨骼模型,术前可以精确测量椎间孔形态的各项参数、建立试行通道、选择手术入路和方式、预判椎间孔成形、预估手术难度,对经皮脊柱内窥镜下腰椎间盘摘除术的术中操作具有指导意义。

Application of 3D printing skeletal models in percutaneous endoscopy lumbar discectomy

Objective To explore the clinical value of 3D printed skeletal model in percutaneous spinal endoscopic lumbar discectomy.Methods Clinical data of 62 patients with lumbar disc herniation admitted to the department of spine surgery of the Third Affiliated Hospital of Suzhou University from July 2016 to October 2017 were retrospectively analyzed. There were 34 males and 28 females, the age ranged from 32 to 67 years, with an average of 52.3 years. The lesion segments were all L4/5 segments, including 8 cases with lateral recess stenosis. The types of disc herniation included 18 cases of paracentral disc herniation, 40 cases of lateral disc herniation and 4 cases of extreme lateral disc herniation. The WSPS V1.0 medical image processing software was used to process the imaging data to generate a GCODE format file recognizable by the 3D printer. A polylactic acid material was used to print a complete segmental lumbar skeletal model by using a 3D printer. According to the location of the lesion, the bilateral intervertebral foramen were divided into the affected side group and the healthy side group. The “5 points and 2 lines” anatomical landmarks were determined on the skeletal model, and the “3 distances and 1 angle”of the intervertebral foramen (intervertebral foramen width, posterior edge height of the intervertebral disc, intervertebral foramen height and ventral inclination angle of the superior articular process) were measured. Endoscopic lumbar discectomy via percutaneous intervertebral foramen approach was performed on all affected sides. According to whether or not foraminoplasty was performed during the operation, the patients were divided into two groups: foraminoplasty group and the non-foraminoplasty group. The “three distances and one angle” of the intervertebral foramen between the affected and healthy sides of the skeletal model, and the “three distances and one angle” of the intervertebral foramen between the foraminoplasty group and the non-foraminoplasty group were compared.Results In the print model, the width of the intervertebral foramen, the height of the posterior edge of the intervertebral disc, the height of the intervertebral foramen and the ventral inclination angle of the superior articular process in the affected side group were (6.30±1.71) mm, (4.88±1.63) mm, (21.07±3.78) mm and 16.28°±1.13°, respectively. The healthy side groups were (7.27±1.86) mm, (5.3±1.71) mm, (18.57±3.34) mm and 25.72°±1.03°, respectively. The width of the intervertebral foramen and the ventral inclination angle of the superior articular process in the affected side group were smaller than those in the healthy side group, and the difference was statistically significant (t=2.133, 2.877, all P values＜0.05). There was no significant difference between the two groups in the height of the posterior edge of the intervertebral disc and the height of the intervertebral foramen (all P values＞0.05). All patients successfully completed the operation. Among them, 38 patients did not undergo foraminoplasty and 24 patients underwent foraminoplasty. Among 62 patients, the width of the affected intervertebral foramen, the height of the posterior edge of the affected intervertebral disc, the height of the affected intervertebral foramen and the ventral inclination angle of the affected superior articular process in the foraminoplasty group were (4.77±0.83) mm, (4.97±1.35) mm, (16.23±2.02) mm and 11.50°±2.15°, respectively, and those in the non-foraminoplasty group were (7.42±1.24) mm, (5.19±1.88)mm, (16.63±1.94) mm and 22.22°±4.28°, respectively. The width of intervertebral foramen, the height of posterior edge of intervertebral disc and the ventral inclination angle of the superior articular process in foraminoplasty group were smaller than those in non-foraminoplasty group. There were significant differences in the width of intervertebral foramen and the ventral inclination angle of superior articular process (t=6.681, 8.001, all P values＜0.05), but there were no significant differences in the height of posterior edge of intervertebral disc and the height of intervertebral foramen between the two groups (all P values＞0.05). The width of intervertebral foramen was 3.34-5.92 mm and the ventral inclination angle of superior articular process was 9°-14° in 24 patients undergoing foraminoplasty. The results showed that the width of the affected intervertebral foramen was less than 6.0 mm and the ventral inclination angle of the superior articular process was less than 15° in L_4/5 segment patients undergoing intervertebral foraminoplasty.Conclusions Using 3D printing skeleton model, the parameters of intervertebral foramen shape can be accurately measured before operation, the trial pathway can be established, the surgical approach and method can be selected, the foraminoplasty and can be predicted and the difficulty of operation can be predicted. It has guiding significance for the operation of percutaneous endoscopic lumbar discectomy.