Department of Spine Surgery, the First Affiliated Hospital of Sun Yat-sen University, Guangzhou, China.
Spine (Phila Pa 1976). 2013 Jul 1;38(15):E925-9. doi: 10.1097/BRS.0b013e3182967968.
An in vitro biomechanical study of 3 lumbosacral fixation techniques in human cadaveric lumbar-pelvic spine models.
To compare the in vitro biomechanical effect of a novel 4-rod lumbosacral reconstruction technique with conventional techniques in a human cadaveric lumbopelvic model, and to evaluate the benefit of adding supplementary rod fixation.
Spinopelvic fixation involving the sacrum remains a difficult clinical challenge. Numerous lumbopelvic reconstruction methods based on the Galveston 2-rod technique have been proposed. Recently, a novel technique using supporting longitudinal rods across the lumbopelvic junction was reported. However, no comparative in vitro biomechanical testing was performed to evaluate the benefit of adding supplementary fixation at the L5-S1 levels.
Seven fresh-frozen cadaveric lumbar-pelvic spines were prepared and tested for bone mineral density. The intact cadavers underwent a flexibility test, followed by insertion of the instrumented construct. Three constructs were tested: S1 screws alone (group 1), S1 screws plus iliac screws (group 2), and the 4-rod technique (group 3). Rotational angles of the L1-S1 and L5-S1 segments were measured to study the stability of the 3 lumbosacral fixation constructs compared with the intact spine. Nondestructive, multidirectional flexibility tests that included 4 loading methods followed by a destructive flexural load to failure were performed using an material testing machine. The lumbosacral peak range of motion (ROM) (millimeters or degrees) and ultimate failure load (Nm) of the 3 reconstruction techniques were statistically compared using a 1-way analysis of variance combined with a Student-Newman-Keuls post hoc test.
The average bone mineral density of the 7 specimens was 0.81 ± 0.09 g/cm. The ROM of the 3 fixation constructs was significantly smaller than that of the intact group in all 6 directions (P < 0.05). In lateral bending, the ROM of groups 2 and 3 was significantly smaller than that of group 1 (P < 0.05), but groups 2 and 3 were not significantly different from each other (P > 0.05). In flexion-extension, the ROM of groups 1 and 3 was significantly smaller than group 2 (P < 0.05), but groups 1 and 3 were not significantly different from each other (P > 0.05). In axial rotation, the ROM of group 3 was significantly smaller than those of groups 1 and 2 (P < 0.05), but groups 1 and 2 were not significantly different from each other (P > 0.05).
The 4-rod technique achieved stable biomechanical effects in lumbosacral fixation. At the L5-S1 junction, the 4-rod technique demonstrated better stability than the constructs using S1 screws or S1 screws plus iliac screws..
在人体腰椎骨盆脊柱模型中，对 3 种腰骶固定技术的体外生物力学研究。
比较一种新型 4 棒腰骶重建技术与传统技术在人体腰椎骨盆模型中的体外生物力学效果，并评估添加附加棒固定的益处。
涉及骶骨的脊柱固定仍然是一个具有挑战性的临床难题。已经提出了许多基于 Galveston 2 棒技术的腰骶重建方法。最近，报道了一种使用穿过腰骶交界处的支撑纵向棒的新型技术。然而，没有进行比较性的体外生物力学测试来评估在 L5-S1 水平添加补充固定的益处。
准备并测试了 7 个新鲜冷冻的腰椎骨盆脊柱进行骨矿物质密度检查。完整的尸体进行了柔韧性测试，然后插入仪器化的结构。测试了 3 种结构：单独的 S1 螺钉（第 1 组）、S1 螺钉加髂骨螺钉（第 2 组）和 4 棒技术（第 3 组）。测量 L1-S1 和 L5-S1 节段的旋转角度，以研究 3 种腰骶固定结构与完整脊柱的稳定性。使用材料试验机进行了非破坏性的多向柔韧性测试，包括 4 种加载方法，然后进行破坏性弯曲失效测试。使用单向方差分析结合学生-纽曼-凯尔斯事后检验对 3 种重建技术的腰骶最大活动范围（毫米或度）和最终失效载荷（Nm）进行统计学比较。
7 个标本的平均骨矿物质密度为 0.81 ± 0.09 g/cm。在所有 6 个方向上，3 个固定结构的 ROM 均明显小于完整组（P < 0.05）。在侧屈时，第 2 组和第 3 组的 ROM 明显小于第 1 组（P < 0.05），但第 2 组和第 3 组之间无显著差异（P > 0.05）。在屈伸时，第 1 组和第 3 组的 ROM 明显小于第 2 组（P < 0.05），但第 1 组和第 3 组之间无显著差异（P > 0.05）。在轴向旋转时，第 3 组的 ROM 明显小于第 1 组和第 2 组（P < 0.05），但第 1 组和第 2 组之间无显著差异（P > 0.05）。
4 棒技术在腰骶固定中实现了稳定的生物力学效果。在 L5-S1 交界处，4 棒技术在稳定性方面优于使用 S1 螺钉或 S1 螺钉加髂骨螺钉的结构。
