Park Daniel K, Lee Michael J, Lin Eric L, Singh Kern, An Howard S, Phillips Frank M
Rush University Medical Center, Chicago, IL 60612, USA.
J Spinal Disord Tech. 2010 Jun;23(4):223-8. doi: 10.1097/BSD.0b013e3181a9d540.
A cadaveric study.
To define the relationship of the lumbar exiting nerve root and trunks within the psoas muscle with reference to the radiographic center of the intervertebral disc, the recommended disc access point for the minimally invasive lateral transpsoas approach.
The transpsoas approach to the lumbar intervertebral body disc is a minimally invasive approach used for interbody fusion. This approach carries the potential risk of injury to the intrapsoas nerves. There are no published studies investigating the locations of the intrapsoas neural elements with reference to the transpsoas access corridor developed during minimally invasive lateral approaches to the disc.
Ten human cadaveric specimens were analyzed. A guide wire was placed in each disc space center under lateral fluoroscopic guidance as has been recommended for disc access in the transpsoas fusion technique. Using calipers, the distances from the exiting nerve and trunk to the wire were measured.
In general, the nerve trunk was a mean of 14 mm posterior to the center of the disc and was a mean of 5 mm closer to the center of the disc than the exited nerve. The trunks were closer to the center of the disc caudally in the lumbar spine, with the distance ranging from a mean of 16.4 mm at L2-3 to 10.6 mm at the L4-5 level. The intrapsoas location of the exited nerve was less variable and was greater than 15 mm from the projected center of the disc. At L4-5, the trunk approximated the center of the disc in 15% of specimens.
This study suggests that the intrapsoas nerves are a safe distance from the radiographic center of the intervertebral disc in a majority of cases; however, anatomic variations in the location of these nerves place them at injury risk in a small number of cases. These results suggest that neural monitoring whereas traversing the psoas may be important to enhance the safety of the transpsoas approach. Care is particularly warranted at the L4-5 level.
尸体研究。
参照椎间盘的影像学中心（微创外侧经腰大肌入路推荐的椎间盘穿刺点），明确腰大肌内腰神经根及神经干的关系。
经腰大肌入路行腰椎椎体间融合术是一种用于椎间融合的微创入路。该入路存在损伤腰大肌内神经的潜在风险。目前尚无已发表的研究探讨在微创外侧椎间盘入路过程中，腰大肌内神经结构相对于经腰大肌入路通道的位置。
分析10例人体尸体标本。按照经腰大肌融合技术中推荐的椎间盘穿刺方法，在侧位透视引导下将导丝置于每个椎间盘间隙中心。使用卡尺测量神经及神经干与导丝之间的距离。
总体而言，神经干平均位于椎间盘中心后方14mm处，且比穿出神经平均更靠近椎间盘中心5mm。在腰椎尾侧，神经干更靠近椎间盘中心，距离范围从L2 - 3节段的平均16.4mm到L4 - 5节段的10.6mm。穿出神经在腰大肌内的位置变异性较小，距椎间盘投影中心大于15mm。在L4 - 5节段，15%的标本中神经干接近椎间盘中心。
本研究表明，在大多数情况下，腰大肌内神经距椎间盘影像学中心有安全距离；然而，这些神经位置的解剖变异在少数情况下使其面临损伤风险。这些结果表明，在经腰大肌入路过程中进行神经监测可能对提高该入路的安全性很重要。在L4 - 5节段尤其需要谨慎操作。
