【作者】 王显钢；

【导师】 刘一；

【作者基本信息】 吉林大学 ， 外科学， 2004， 硕士

【摘要】 目的：采用术后CT回顾性分析置入的68枚胸椎椎弓根镙钉来决定胸椎椎弓根镙钉内固定术在脊柱外科应用（包括脊柱侧凸中）中的总体准确性和危险性，以及椎弓根内外、前方皮质穿破的关联因素.方法：本组病人均采用中华富乐椎弓根螺钉系统进行手感法内固定，由同一位有多年腰椎椎弓根镙钉内固定经验的医师植入，所有螺钉的植入均通过术中x线荧屏正侧位辅助判断位置，术中均采用了脊髓监测。T1~T10的进钉点采用横突水平线上缘与小关节突竖直中线的交点，T11～T12采用横突水平中线与小关节水平中线的交点。T1~T10采用4.5mm直径的螺钉，T11~T12采用5.5或6.5mm直径的螺钉。采用徒手法植入椎弓根镙钉，利用术后CT评价植入胸椎椎弓根和锥体的钉的准确性，由三名脊柱外科医师配合一名放射医师来通过术后CT观测椎弓根的皮质移位移位情况。同时也测量了横向螺钉角度 (TSA) ，椎弓根皮质移位分成两大组四类：有侧凸组和无侧凸组，椎弓根皮质移位程度按2mm为级别进行分类，根据移位程度分I，II，III，IV四类：I.0~2.0mm，II.2.1~4.0mm, III.4.1~6.0mm, IV.6.1~8.0mm。对镙钉进行了区域性的分类对比（上中下胸椎），植入的镙钉于是也被按照是否内侧皮质移位<2mm,外侧皮质移位<6mm，分为可接受镙钉，即AP镙钉，指内侧皮质移位<2mm,外侧皮质移位<6mm的镙钉；和完全植入镙钉，即TC镙钉。前方椎体皮质穿破通过沿着螺钉中轴来测量判断其穿出的具体mm数值，对比分析了无皮质移位时与有各种皮质移位时的椎弓根横向镙钉角度（TSA）。以椎体横断面的中线为参考来测量横向螺钉角度TSA，即其与椎弓根镙钉轴线的夹角。并对比了有侧凸组和无侧凸组的准确性差异。结果：在采用脊柱后路固定融合的手术中共植入68枚胸椎椎弓根镙钉，<WP=55>它们分布于有脊柱侧凸畸形或无脊柱侧凸的10位患者中。镙钉直径范围（4.5mm～6.5mm），97％基本完全植入椎弓根（即为可接受镙钉），60％完全植入椎弓根（完全包容的镙钉）。内侧椎弓根皮质移位率为12％，但只有2枚(2.9%)侵犯椎管程度>2mm,外侧皮质移位率相对最高19％，明显高于内侧皮质移位（p<0.05）。前方皮质移位平均1.5mm。在27枚移位椎弓根皮质的螺钉中，50％移位外侧，明显高于内侧30%.(p<0.05)和前方皮质移位20%. 在内侧皮质移位的螺钉中，8.8％（6枚）为I类，2.9％（2枚）为II类，III，IV类为0枚；在外侧皮质移位的螺钉中，10.2％（7枚）为I类，7.4％（5枚）为II类，1％（1枚）为III类，IV类0枚。值得一提的是，内侧皮质移位为II类，即>2mm的只有2枚。完全植入的镙钉平均TSA为14.5度，与有内外侧移位有显著差异(p<0.05)，内侧皮质移位者平均TSA17度，外侧11度。前方皮质移位者平均TSA最小（10.0），且常常于外侧皮质移位同时伴随发生(p<0.05)。按区域划分，其中上（T1～T4）17枚，中段（T5～T8）23枚，下段（T9～T12）28枚，在各段完全植入的比率无明显差异（分别为59%，61%，60%）。位置可接受镙钉(AP镙钉)在有侧凸组和无侧凸组均为97%，完全植入的镙钉（TC镙钉）准确率在有侧凸组（58%）稍低，无侧凸组（62%），但也无统计学上的差异（p>0.05）。均无血管和脊髓损伤并发症。结论：97%的螺钉为可接受的准确镙钉(AP镙钉). 皮质有无移位组均无血管神经并发症。经胸椎椎弓根镙钉内固定术总体上安全可靠。螺钉的准确性在有侧凸组和无侧凸组没有显著差异，螺钉的准确性在胸椎各段亦无明显差异。完全植入的螺钉与有内外侧皮质移位的螺钉TSA有统计学上的差异(p<0.05)。前方皮质移位通常伴有外侧皮质移位，而且平均TSA角度更小。更多还原

【Abstract】 Study Design:A prospective observational study to evaluate the accuracy of 68 transpedicular thoracic screws placed in patients with and without idiopathic scoliosis using postoperative computed tomography (CT) and to establish its risks and benefits.Summary of Background Data:. Lumbar pedicle screw instrumentation has proven tobe reliable and effective in the spine surgical management of scoliosis. No domestic reports exist on the accuracy and benefits of pedicle screw instrumentation of the thoracic spine including in scoliosis surgery.Materials and Methods:In all the 68 thoracic pedicle screws placed in 10 patients,we use chinese fule pedicle screw system,and pedicle screws were by the same surgeon who has many years of experences on pedicle screw implantion,during opertion we use c armed x-ray to see the position of the screws.with regards to the entry site,we use the intersection of a vertical line bisecting the facet joint and a horizontal line located at the superior border of the transverse process for T1-T10 or the midline of the transverse process at T11-T12 defined the pedicle entrance point. 68 thoracic pedicle screws in 10 patients with and without idiopathic scoliosis were investigated shortly after surgery by computed tomography. The accuracy of thoracic screw placement within the pedicle and vertebral body were assessed by postoperative CT. Cortical perforations of the pedicle were graded in 2-mm increments. and grouped into 4 groups:I.0~2.0mm，II.2.1~4.0mm, <WP=57>III.4.1~6.0mm, IV.6.1~8.0mm . And defined “acceptably positioned (AP) screws” includes:<= 2 mm of medial or <= 6 mm of lateral pedicle perforation. Screws were regionally grouped for analysis. upper thoracic,middle thoracic and lower thoracic..The transverse screw angle (TSA) between with-penetration group and without-penetration group were measured and analysed. The accuracy of thoracic screw placement between with-deformity group and without coronal deformity group were compared and analysed.Results:68 titanium thoracic pedicle screws of various diameters (4.5-6.5mm)were placed in ten patients who underwent instrumented posterior spinal fusion. The regional distribution of the screws was 17 screws at T1-T4, 23 screws at T5-T8, and 28screws at T9-T12. 97% of the screws are mainly-totally within pedicles(acceptable positioned screws), 60% of screws were totally confined within the pedicle. Although medial perforation of the pedicle wall occurred in 12% of screws, in <1% there was > mm of canal intrusion. Lateral pedicular perforation occurred in 50% of perforating screws and was significantly more common than medial perforation (P < 0. 05). 6 screws penetrated the anterior vertebral cortex by an average of 1.7 mm. Screws inserted between T1 and T4 had no difference in the incidence of full containment within the pedicle and vertebral body (P >0.05) compared with T9–T12. The mean TSA for screws localized within the pedicle was 14.5° and was significantly different from screws with either medial (mean 17°) or lateral (mean 11.0°) pedicle perforation (P < 0. 05). Anterior vertebral penetration was associated with a <WP=58>smaller mean TSA of 10.0° (P <0.05) and with lateral pedicle perforation (P < 0.05). There was no statistic difference between the overall percentages of acceptably positioned screws (<= 2 mm of medial or <= 6 mm of lateral pedicle perforation) in patients with coronal plane spinal deformities (97%) versus patients without coronal plane spinal deformities (97%) (P>0.05).There were no neurologic or vascular complications.Conclusions:Ninety-Seven percent of screws were fully contained or were inserted with either <=2 mm of medial cortical perforation or an acceptable lateral breech. there is no neurologic and vascular compromise in both with-penetration and without-penetration groups. Thoracic pedicle screw fixation is a reliable method including treating spinalde formities. Anterior cortical penetration occurred significantly more often with lateral pedicle perforation and with a smaller mean更多还原