Jackson R P, McManus A C
Spine & Scoliosis Surgery, North Kansas City Hospital, Missouri.
Spine (Phila Pa 1976). 1993 Aug;18(10):1318-28.
Fifty randomly selected computed tomographic (CT) scans of the lumbosacral spine (25 males and 25 females) were studied to determine: 1) if the lateral sacral masses could safely accept a 7 mm diameter rod (i.e., intrasacral rod insertion) and 2) what percentage of patients, both males and females, demonstrated coverage of the posterolateral sacrum by the ilia (i.e., iliac buttressing). In all patients the lateral masses (i.e., the lateral intrasacral mass measurements) appeared wide enough on CT to allow for safe insertion of a 7 mm diameter rod, or other similar size implant, down to at least the level of S2. The smallest distance measured for the width between the posteromedial margin of the sacroiliac joint and the lateral cortex of the S1 neuroforamen (i.e., the lateral intrasacral mass measurement) at its location approximately midway (anteroposterior) through the sacrum on CT cuts was 17 mm (mean 28 mm). This would appear to give adequate room for a 7 mm diameter rod to be inserted at this level in the lateral sacrum (i.e., intrasacral rod insertion). Forty-six patients (24 males, 96%; and 22 females, 88%) appeared to have sufficient CT coverage of the sacrum to conceptually provide for so called "sacroiliac buttressing" of rods, if rods or other implants were to be inserted distally into the lateral masses. After a review of the sacral anatomy by CT it appears that: 1) insertion of rods into the lateral sacral masses (i.e. intrasacral rod insertions), or intrasacral fixation with other similar size implants, would be possible and apparently safe; and 2) the ilia along with the sacroiliac interosseous ligaments sufficiently surround the back and sides of the posterolateral sacrum in most patients (92%), at least by CT assessment, to conceptually offer an indirect "buttress" for implants so inserted. Theoretically, this could biomechanically help resist the flexural loads across the lumbosacral level and possibly provide a method for improved sacral fixation with spinal instrumentation in certain patients.
对50例随机选取的腰骶椎计算机断层扫描（CT）图像（25例男性和25例女性）进行研究，以确定：1）骶骨外侧块是否能安全容纳直径7mm的棒（即骶骨内棒插入）；2）男性和女性患者中，有多大比例的患者其骶骨后外侧被髂骨覆盖（即髂骨支撑）。在所有患者中，CT显示外侧块（即骶骨内外侧块测量值）足够宽，可安全插入直径7mm的棒或其他类似尺寸的植入物，至少可插入至S2水平。在CT图像上，通过骶骨前后径中点位置测量的骶髂关节后内侧缘与S1神经孔外侧皮质之间的最小宽度（即骶骨内外侧块测量值）为17mm（平均28mm）。这似乎为在骶骨外侧此水平插入直径7mm的棒（即骶骨内棒插入）提供了足够的空间。46例患者（24例男性，占96%；22例女性，占88%）的CT图像显示，骶骨有足够的覆盖范围，从概念上讲，如果将棒或其他植入物向远侧插入外侧块，可提供所谓的“骶髂支撑”。通过CT对骶骨解剖结构进行评估后发现：1）将棒插入骶骨外侧块（即骶骨内棒插入）或使用其他类似尺寸的植入物进行骶骨内固定是可行的，且显然是安全的；2）在大多数患者（92%）中，至少通过CT评估，髂骨与骶髂骨间韧带充分环绕骶骨后外侧的后部和侧面，从概念上讲可为如此插入的植入物提供间接“支撑”。从理论上讲，这在生物力学上有助于抵抗腰骶水平的弯曲负荷，并可能为某些患者提供一种通过脊柱内固定改善骶骨固定的方法。
