Epstein Nancy E, Silvergleide Richard S, Black Karen
The Department of Neurosurgery, The North Shore-Long Island Jewish Health System, 300 Community Drive, Manhasset, NY 11030, USA.
Spine J. 2002 Mar-Apr;2(2):129-33. doi: 10.1016/s1529-9430(01)00154-1.
Static and dynamic X-ray studies routinely determine whether or not fusion of a fibula strut allograft has occurred after multilevel anterior corpectomy with fusion (ACF) combined with posterior wiring and fusion (PWF).
Two-dimensional (2D) computed tomography (CT) studies were assessed for documentation of bony ingrowth into fresh frozen fibula strut allograft to constitute an additional sign of fusion.
STUDY DESIGN/SETTING: This was a prospective, nonrandomized study, which was conducted at a university medical center.
Eighteen patients with moderate to severe myelopathy undergoing circumferential cervical surgery for ossification of the posterior longitudinal ligament and spondylostenosis were evaluated.
Static and dynamic X-rays and 2D CT examinations were performed in 18 patients 3 and 6 months after circumferential cervical procedures.
Fusion was assessed on static and dynamic X-rays, and 2D CT studies performed in 18 patients following average 2.9 level anterior corpectomy with fusion (ACF) with posterior wiring and fusion (PWF) (C2-T1) with halo application. Routine fusion criteria on static radiographs included the documentation of bony trabeculation and absence of bony lucency at the graft/vertebral end plate interface. Routine dynamic X-ray criteria of fusion mandated that less than 3.5 mm of translation, less than 20 degrees of angulation, and less than 1 mm of motion be observed between adjacent spinous processes. Here, a potential additional 2D CT criterion for fusion, progressive bony ingrowth into the central shaft of a fibula strut allograft, was investigated on 3 and 6 month postoperative 2D CT examinations using direct measurement of Hounsfield units. Telescoping (mm) was also differentiated from ingrowth into the bony shaft based on a comparison of immediate, 3 and 6 month postoperative CT studies.
Immediate postoperative baseline 2D CT studies revealed no bone within the central canal but an average of less than 1 mm of cephalad and 2.3 mm of caudad graft telescoping. Within 6 postoperative months, 2D CT studies demonstrated an average of 3.5 mm of superior and 4.6 mm of inferior bony ingrowth (confirmed by measuring 500 to 900 Hounsfield units) into the central fibula canal of 17 of 18 patients (94%). Seventeen had routine/dynamic X-ray and CT studies confirming fusion.
Two-dimensional CT evidence of bony ingrowth into the central canal of fibula strut allografts after multilevel ACF/PWF provided an additional means of quantifying the extent of fusion.
在多节段前路椎体次全切除融合术（ACF）联合后路钢丝固定融合术（PWF）后，静态和动态X线研究通常用于确定腓骨支撑植骨是否已融合。
评估二维（2D）计算机断层扫描（CT）研究，以记录骨长入新鲜冷冻腓骨支撑植骨的情况，作为融合的一个额外征象。
研究设计/地点：这是一项在大学医学中心进行的前瞻性、非随机研究。
对18例因后纵韧带骨化和脊柱狭窄而接受颈椎环形手术的中度至重度脊髓病患者进行了评估。
对18例患者在颈椎环形手术后3个月和6个月进行静态和动态X线检查以及2D CT检查。
对18例患者平均进行2.9节段前路椎体次全切除融合术（ACF）联合后路钢丝固定融合术（PWF）（C2-T1）并应用头环后，通过静态和动态X线以及2D CT研究评估融合情况。静态X线片上的常规融合标准包括记录移植骨/椎体终板界面处的骨小梁形成以及无骨质透亮区。融合的常规动态X线标准要求相邻棘突间的平移小于3.5 mm、成角小于20度且活动小于1 mm。在此，通过直接测量亨氏单位，在术后3个月和6个月的2D CT检查中研究了一种潜在的额外融合2D CT标准，即骨逐渐长入腓骨支撑植骨的中心轴。还通过比较术后即刻、3个月和6个月的CT研究，区分了伸缩（mm）与骨长入骨干的情况。
术后即刻的基线2D CT研究显示中央管内无骨，但平均头侧移植骨伸缩小于1 mm，尾侧为2.3 mm。术后6个月内，2D CT研究显示18例患者中有17例（94%）的腓骨中心管平均有3.5 mm的上向和4.6 mm的下向骨长入（通过测量500至900亨氏单位证实）。17例患者的常规/动态X线和CT研究证实了融合。
多节段ACF/PWF术后，2D CT显示骨长入腓骨支撑植骨中央管，为量化融合程度提供了一种额外方法。
