Background context

The effect of the posterior midline approach to the lumbar spine, relevance of inter- and supraspinous ligament (ISL&SSL) sparing, and potential of different wound closure techniques are largely unknown despite their common use.

Purpose

The aim of this study was to quantify the effect of the posterior approach, ISL&SSL resection, and different suture techniques.

Study Design

Biomechanical cadaveric study.

Methods

Five fresh frozen human torsi were stabilized at the pelvis in the erect position. The torsi were passively loaded into the forward bending position and the sagittal angulation of the sacrum, L4 and T12 were measured after a level-wise posterior surgical approach from L5/S1 to T12/L1 and after a level-wise ISL&SSL dissection of the same sequence. The measurements were repeated after the surgical closure of the thoracolumbar fascia with and without suturing the fascia to the spinous processes.

Results

Passive spinal flexion was increased by 0.8±0.3° with every spinal level accessed by the posterior approach. With each additional ISL&SSL resection, a total increase of 1.6±0.4° was recorded. Suturing of the thoracolumbar fascia reduced this loss of resistance against lumbar flexion by 70%. If the ISL&SSL were resected, fascial closure reduced the lumbar flexion by 40% only. In both settings, suturing the fascia to the spinous processes did not result in a significantly different result (p=.523 and p=.730 respectively).

Conclusion

Each level accessed by a posterior midline approach is directly related to a loss of resistance against passive spinal flexion. Additional resection of ISL&SSL multiplies it by a factor of two.

Clinical Significance

The surgical closure of the thoracolumbar fascia can reduce the above mentioned loss of resistance partially. Suturing the fascia to the spinal processes does not result in improved passive stability.

中文翻译：

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腰椎后路手术入路的生物力学考虑

背景语境

后中线入路对腰椎的影响、棘间韧带和棘上韧带 (ISL&SSL) 保护的相关性，以及不同伤口闭合技术的潜力，尽管它们被广泛使用，但在很大程度上是未知的。

目的

本研究的目的是量化后入路、ISL&SSL 切除和不同缝合技术的效果。

学习规划

生物力学尸体研究。

方法

五个新鲜的冷冻人体躯干被固定在直立位置的骨盆处。在从 L5/S1 到 T12/L1 的水平后路手术入路和水平 ISL&SSL 解剖后，将躯干被动加载到前屈位置，并测量骶骨、L4 和 T12 的矢状角顺序。在将筋膜缝合和不缝合到棘突上的胸腰筋膜手术闭合后重复测量。

结果

被动脊柱屈曲增加了 0.8±0.3°，后入路进入每个脊柱水平。每增加一次 ISL 和 SSL 切除，记录的总增加量为 1.6±0.4°。胸腰筋膜的缝合减少了 70% 的腰椎屈曲阻力损失。如果 ISL&SSL 被切除，筋膜闭合仅使腰椎屈曲减少 40%。在这两种设置中，将筋膜缝合到棘突并没有导致明显不同的结果（分别为 p=.523 和 p=.730）。

结论

后中线入路进入的每个节段与被动脊柱屈曲阻力的丧失直接相关。ISL&SSL 的附加切除将其乘以两倍。

临床意义

胸腰筋膜手术闭合可部分减轻上述阻力损失。将筋膜缝合到脊柱突不会改善被动稳定性。