Dang Alan B C, Hu Serena S, Tay Bobby K-B
Department of Orthopaedic Surgery, New England Musculoskeletal Institute, University of Connecticut Health Center, Farmington, CT 06034-4037, USA.
Spine (Phila Pa 1976). 2008 Mar 15;33(6):607-11. doi: 10.1097/BRS.0b013e318166e01d.
A computational study of anterior longitudinal ligament (ALL) strain in the cervical spine following single- and 2-level fusion during simulated whiplash.
To evaluate how cervical fusion alters the peak strain of the ALL in the adjacent motion segments.
Although an in vitro study of ALL strain during whiplash has been conducted in healthy cervical spines, no such study has been performed in a cervical spine with fused segments. It has been demonstrated that the loss of motion following fusion results in increased strain in the adjacent motion segments. However, the biomechanics of the adjacent motion segments during high energy acceleration-deceleration simulations have not been widely reported. Accordingly, we investigated the peak strain of the ALL following single- and 2-level fusion during simulated whiplash.
A detailed finite element (FE) model of the human body in the driver-occupant position was used to investigate cervical hyperextension injury. The cervical spine was subjected to simulated whiplash at 8 g acceleration and peak ALL strains were computed. The results were validated against published experimental data. This validated FE model was then modified to simulate single- and 2-level fusion and tested under identical loading conditions.
The mean increase in peak ALL strain at the motion segment immediately adjacent to the level of fusion was 15.5% for single-level fusion when compared with 40.8% in 2-level contiguous fusion (P = 0.019).
Cervical arthrodesis increases peak ALL strain in the adjacent motion segments. Two-level fusion increased ALL strain in the adjacent motion segments, on average, greater than single-level fusion did. Disc arthroplasty and other techniques that provide stability without loss of flexibility may be beneficial in patients undergoing multiple-level fusion. Detailed FE models such as ours can provide strong correlation with experimentally determined data.
一项关于模拟挥鞭伤期间颈椎单节段和双节段融合后前纵韧带（ALL）应变的计算研究。
评估颈椎融合如何改变相邻运动节段中ALL的峰值应变。
尽管已经对健康颈椎在挥鞭伤期间的ALL应变进行了体外研究，但尚未在有融合节段的颈椎中进行此类研究。已经证明融合后运动丧失会导致相邻运动节段的应变增加。然而，在高能量加速 - 减速模拟期间相邻运动节段的生物力学尚未得到广泛报道。因此，我们研究了模拟挥鞭伤期间单节段和双节段融合后ALL的峰值应变。
使用处于驾驶员 - 乘客位置的人体详细有限元（FE）模型来研究颈椎过伸损伤。颈椎在8g加速度下进行模拟挥鞭伤，并计算ALL的峰值应变。结果与已发表的实验数据进行了验证。然后对这个经过验证的FE模型进行修改以模拟单节段和双节段融合，并在相同的加载条件下进行测试。
与双节段连续融合时的40.8%相比，单节段融合时紧邻融合节段的运动节段中ALL峰值应变的平均增加为15.5%（P = 0.019）。
颈椎融合增加了相邻运动节段中ALL的峰值应变。平均而言，双节段融合比单节段融合使相邻运动节段中的ALL应变增加得更多。椎间盘置换术和其他在不丧失灵活性的情况下提供稳定性的技术可能对接受多节段融合的患者有益。像我们这样的详细FE模型可以与实验确定的数据有很强的相关性。
