Singhatanadgige Weerasak, Songthong Kittisak, Pholprajug Phattareeya, Yingsakmongkol Wicharn, Kotheeranurak Vit, Limthongkul Worawat
Department of Orthopaedics, Faculty of Medicine, 26683Chulalongkorn University and King Chulalongkorn Memorial Hospital, Bangkok, Thailand.
Queen Savang Vadhana Memorial Hospital, Chonburi, Thailand.
Global Spine J. 2022 Jun;12(5):765-771. doi: 10.1177/2192568220962444. Epub 2020 Oct 14.
Anatomic cadaver study.
Translaminar facet screw fixation supplements unilateral pedicle screw-rod fixation in minimally invasive transforaminal lumbar interbody fusion (TLIF). Various screw diameters, lengths, trajectories, and insertion points are used; however, they do not represent true screw trajectory. We aimed to evaluate lumbar laminar anatomy and suggest a safe and effective insertion point and trajectory during lumbar-translaminar facet screw fixation in an anatomic cadaver study.
O-arm navigation simulating the true translaminar facet screw trajectory was used to evaluate L1-S1 in cadaveric spines. The inner and outer diameters, length, and trajectory of the screw pathway were measured along the trajectory from the spinous process base through the contralateral lamina, crossing the facet joint to the transverse process base using 2 starting points: cephalad one-third (1/3SL) and one-half (1/2SL) of the spinolaminar junction.
Using the 1/2SL starting point, the outer and inner lamina diameters did not differ significantly from L1-L5 (7.47 ± 1.38 to 6.7 ± 1.84 mm and 4.73 ± 1.04 to 3.86 ± 1.46 mm, respectively). Screw length (36.16 ± 4.02 to 49.29 ± 10.07 mm) and lateral angle increased (50.28° ± 8.78° to 60.77° ± 8.88°), but caudal angle decreased (16.19° ± 9.01° to 1.13° ± 11.31°). Lamina diameter and screw length did not differ with different starting points. L2-L3 caudal angles were lower in the 1/2SL starting point.
A 36- to 50-mm translaminar facet screw-with 5.0-mm diameter for L1-L2 and 4.5-mm diameter for L3-L5-can be inserted at the middle of the spinolamina, especially during minimally invasive TLIF, with a 50° to 60° lateral angle relative to the spinous process, and a caudal angle of 16° to 1° relative to the spinolamina from L1-L5.
解剖学尸体研究。
在微创经椎间孔腰椎椎间融合术（TLIF）中，经椎板小关节螺钉固定可辅助单侧椎弓根螺钉-棒固定。使用了各种螺钉直径、长度、轨迹和置入点；然而，它们并不代表真正的螺钉轨迹。我们旨在通过解剖学尸体研究评估腰椎椎板解剖结构，并提出腰椎经椎板小关节螺钉固定期间安全有效的置入点和轨迹。
使用模拟真正经椎板小关节螺钉轨迹的O型臂导航系统评估尸体脊柱的L1-S1节段。从棘突根部沿轨迹穿过对侧椎板、小关节至横突根部，通过两个起始点测量螺钉通道的内径、外径、长度和轨迹：棘突-椎板连接的头侧三分之一（1/3SL）和二分之一（1/2SL）。
使用1/2SL起始点时，L1-L5的椎板外径和内径差异无统计学意义（分别为7.47±1.38至6.7±1.84mm和4.73±1.04至3.86±1.46mm）。螺钉长度（36.16±4.02至49.29±10.07mm）和外侧角度增加（50.28°±8.78°至60.77°±8.88°），但尾侧角度减小（16.19°±9.01°至1.13°±11.31°）。不同起始点的椎板直径和螺钉长度无差异。1/2SL起始点的L2-L3尾侧角度较低。
可在棘突-椎板交界处中部置入直径为36至50mm的经椎板小关节螺钉，L1-L2为5.0mm，L3-L5为4.5mm，特别是在微创TLIF期间，相对于棘突的外侧角度为50°至60°，相对于L1-L5的棘突-椎板的尾侧角度为16°至1°。
