Barber Sean M, Boghani Zain, Steele William, Blacklock J Bob, Trask Todd, Holman Paul
Department of Neurosurgery, Houston Methodist Neurological Institute, Houston Methodist Hospital, Houston, Texas, USA.
Department of Neurosurgery, Houston Methodist Neurological Institute, Houston Methodist Hospital, Houston, Texas, USA.
World Neurosurg. 2017 Nov;107:396-399. doi: 10.1016/j.wneu.2017.07.178. Epub 2017 Aug 7.
The safe working zone for lateral access to the L4/5 disc space has been said to lie in the anteroposterior (AP) midpoint of the disc space due to the location of the femoral nerve at that level. However, the AP location of the psoas muscle (and thus the lumbosacral plexus within) at L4/5 is variable. A psoas muscle lying excessively anteriorly at the L4/5 disc space may preclude safe access to the L4/5 disc space from a lateral transpsoas approach.
Lumbar spine magnetic resonance imaging (MRI) for 300 consecutive patients at the authors' institution were reviewed retrospectively. The AP distance between the ventral aspect of the thecal sac and the dorsal aspect of the psoas muscle at L4/5 was measured, as was the AP diameter of the L4/5 disc space.
The dorsal aspect of the psoas muscle at L4/5 was most commonly found dorsal to the ventral aspect of the thecal sac (zone P, N = 145; 48.3%), whereas it was found at the junction of zones IV/P in 37 patients (12.3%), in zone IV in 85 patients (28.3%), in zone III in 29 patients (9.7%), and in zone II in 4 patients (1.3%).
The location of the psoas muscle in relation to the L4/5 disc space is somewhat variable. In 11% of patients, the dorsal-most aspect of the psoas muscle was located within zones II or III, likely precluding safe access to the L4/5 disc space from a lateral transpsoas approach.
由于股神经在该水平的位置，据说经外侧进入腰4/5椎间盘间隙的安全工作区位于椎间盘间隙的前后（AP）中点。然而，腰4/5水平腰大肌（以及其中的腰骶丛）的前后位置是可变的。腰大肌在腰4/5椎间盘间隙过度靠前可能会妨碍经腰大肌外侧入路安全进入腰4/5椎间盘间隙。
回顾性分析作者所在机构连续300例患者的腰椎磁共振成像（MRI）。测量腰4/5水平硬脊膜囊腹侧与腰大肌背侧之间的前后距离，以及腰4/5椎间盘间隙的前后径。
腰4/5水平腰大肌的背侧最常见于硬脊膜囊腹侧的后方（P区，N = 145；48.3%），而在37例患者中位于IV/P区交界处（12.3%），85例患者位于IV区（28.3%），29例患者位于III区（9.7%），4例患者位于II区（1.3%）。
腰大肌相对于腰4/5椎间盘间隙的位置存在一定变异性。在11%的患者中，腰大肌最靠背侧的部分位于II区或III区，这可能会妨碍经腰大肌外侧入路安全进入腰4/5椎间盘间隙。
