保留后韧带复合体的颈椎管扩大成形术的解剖学研究

Anatomy research of cervical laminoplasty with preservation of the posterior ligament complex

目的评估保留后韧带复合体的颈椎管扩大成形术扩大椎管的可行性。方法选取6具符合标准的人体标本，简单随机分为两组（C4起始组，S4；C5起始组，S5；每组3具），使用保留颈后韧带复合体的新术式按次序进行C3～C6节段的减压手术。每当完成单个节段右侧椎板上的骨槽后，用测深尺在定点测量椎管的基础深度。继续完成对侧的骨槽制作，然后用组织钳将该椎节棘突向后提拉至韧带复合体刚好紧绷，再次测量此刻的椎管深度。计算两次测量值之差得出椎板的后移值（RV）。每当增加一个节段的手术区域，对已测节段要再次进行测量。分别使用两独立样本和单样本资料的t检验对测量结果进行分析。结果两组人体标本在完成首个节段的减压手术后，椎板平均后移值均较小[S4：（0．87±0．72）mm；S5：（1．83±0．29）mm]，而完成C3-C6节段的手术后，椎板后移距离达到最大值RVmax，从c3到C6节段的总体平均RVmax依次为（2．37±0．52）mm、（4．27±0．78）mm、（3．73±0．93）mm和（2．16±0．77）mm；总体平均后移率（RR）依次为17％±7％、32％±9％、29％±10％和16％±6％。CA和c5节段的总体平均RVmax达到或超过了4mm的减压阈值（t=0．839、-0．703，均P〉0．05）。C4／C5节段的平均RVmax在两组中的差异较小（t=-1．204、1．189，均P〉0．05），而C3／C6节段的组间差异较为明显（t=-4．429、4．196，均P〈0．05）。结论保留后韧带复合体的颈椎管扩大成形术能够较好地扩大椎管的矢状径，具有解除脊髓压迫的作用，且各节段椎板的后移值均随手术节段数的增加而加大，但不同节段的后移能力有较大差异，手术区中部的减压效果好于头尾侧。

Objective To evaluate the feasibility of cervical laminoplasty with preservation of the posterior ligament complex for enlarging the spinal canal. Methods Six up-to-standard human corpse specimens were divided into two groups by simple randomization （ start from CA group, S4 ; start from C5 group,S S;3 corpses in each group ）. Decompression operation of C3 - C6 level was performed in a predetermined sequence by using the new procedure with preservation of the posterior ligament complex. The basic depth of spinal canal was measured with a depth gauge at fixed point after the right bone groove of single level was completed. The operation of the contralateral bone groove was continued, and then the spinal canal was measured again when the spinous process was pulled backward by using a tissue forceps until the ligament complex was just tight. Retreat value （RV） of vertebral lamina was obtained by calculating the difference between the two measurements. The earlier measured levels needed to be remeasured when the operation area increased by one level. Two independent sample and one-sample t test were used to analyze the measurement results. Results RV of vertebral lamina was small after finishing the first level of the decompression operation [ S4 ： （ 0. 87 ± 0. 72 ） mm; S5 ： （ 1.83 ± 0. 29 ） mm ], and the value reached its maximum after the completion of C3 - C6 level. The overall average RVmaxs from C3 to C6 level were （2.37 ±0.52） ram, （4.27 ±0.78） mm, （3.73 ±0.93） mm and （2. 16 ±0.77） ram, respectively. The overall average retreat rates （RR） were 17% ±7% , 32% ±9%, 29% ± 10% and 16% ±6%, respectively. The overall average RVmax of C4 and C5 level reached or exceeded the decompression threshold value of 4 mm （t = 0. 839, - 0. 703, both P 〉 0.05 ）. The average RVmax of C4/C5 level was similar in the two groups （t = - 1. 204, 1. 189, both P 〉0.05） ; however, the difference of average RVmax between C3 and C6 level was significant （ t = - 4. 429, 4. 196, both P 〈 0. 05）. Conclusions Cervical laminoplasty with preservation of the posterior ligament complex can enlarge the sagittal diameter of spinal canal and relieve the compression of spinal cord. In addition, RV of each level increases as the number of the operation level increases, and the ability of vertebral lamina to retreat is quite different from C3 to C6 level. The decompression effect in the middle of the operation area is better than that on the cranial and tail side.