Department of Neurosurgery, Rush University Medical Center, Chicago, Illinois; and.
J Neurosurg Spine. 2014 Feb;20(2):178-82. doi: 10.3171/2013.11.SPINE131. Epub 2013 Dec 13.
Iatrogenic foraminal stenosis is a well-known complication in cervical spine surgery. Machined interfacet allograft spacers can provide a large surface area, which ensures solid support, and could potentially increase foraminal space. The authors tested the hypothesis that machined interfacet allograft spacers increase cervical foraminal height and area.
The C4-5, C5-6, and C6-7 facets of 4 fresh adult cadavers were exposed, and the cartilage was removed from each facet using customized rasps. Machined allograft spacers were tamped into the joints. The spines were scanned with the O-arm surgical imaging system before and after placement of the spacers. Two individuals independently measured foraminal height and area on obliquely angled sagittal images.
Foraminal height and area were significantly greater following placement of the machined interfacet spacers at all levels. The Pearson correlation between the 2 radiographic reviewers was very strong (r = 0.971, p = 0.0001), as was the intraclass correlation coefficient (ICC = 0.907, p = 0.0001). The average increase in foraminal height was 1.38 mm. The average increase in foraminal area was 18.4% (0.097 cm(2)) [corrected].
Modest distraction of the facets using machined interfacet allograft spacers can increase foraminal height and area and therefore indirectly decompress the exiting nerve roots. This technique can be useful in treating primary foraminal stenosis and also for preventing iatrogenic foraminal stenosis that may occur when the initially nonlordotic spine is placed into lordosis either with repositioning after central canal decompression or with correction using instrumentation. These grafts may be a useful adjunct to the surgical treatment of cervical spine disease.
医源性椎间孔狭窄是颈椎手术中一种众所周知的并发症。加工界面同种异体移植物 spacer 可提供较大的表面积，确保牢固的支撑，并且有可能增加椎间孔空间。作者检验了加工界面同种异体移植物 spacer 增加颈椎椎间孔高度和面积的假设。
暴露 4 个新鲜成人尸体的 C4-5、C5-6 和 C6-7 关节面，使用定制的 Rasps 去除每个关节面的软骨。将加工的同种异体移植物 spacer 填入关节。在放置 spacer 前后，使用 O-arm 手术成像系统对脊柱进行扫描。两名独立的个体在斜矢状图像上测量椎间孔高度和面积。
在所有水平，放置加工界面界面移植物 spacer 后椎间孔高度和面积显著增加。两名放射学审查员之间的 Pearson 相关性非常强（r = 0.971，p = 0.0001），组内相关系数（ICC = 0.907，p = 0.0001）也很强。椎间孔高度的平均增加为 1.38 毫米。椎间孔面积的平均增加为 18.4%（0.097 cm²）[校正]。
使用加工界面同种异体移植物 spacer 适度分散关节面可以增加椎间孔高度和面积，从而间接减压出口神经根。该技术可用于治疗原发性椎间孔狭窄，也可预防在非直线脊柱初始放置于前凸时可能发生的医源性椎间孔狭窄，无论是在中央管减压后重新定位还是使用器械矫正时。这些移植物可能是颈椎疾病手术治疗的有用辅助手段。
