Skipped pedicle screws.
Skipped pedicle screws.
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跳过椎弓根螺钉。
DOI：
10.3171/2011.2.spine11111
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发表时间：
2011
期刊：
影响因子：
--
通讯作者：
Alexander R Vacaro
中科院分区：
文献类型：
--
作者：
C. Kepler;Alexander R Vacaro
Hwang等人2介绍了一个可能与所有对脊柱畸形患者进行手术的外科医生相关的关注主题。他们的研究本质上是一项概念验证研究，旨在通过在凹侧每隔一个节段跳过一个节段，在弯曲的凸侧仅使用少量螺钉来减少畸形手术中使用的椎弓根螺钉数量。虽然有趣，但得出的任何结论都必须限于青少年特发性脊柱侧凸（AIS）患者的研究，因为该人群的骨质量和弯曲度上级。其他脊柱畸形患者，如退行性脊柱侧凸患者，骨质较差的人群，3，6可能也没有反应。作者承认这一缺点，他们推迟了该技术在大畸形或僵硬弯曲患者中的使用，这些患者需要更多的力来实现和保持矫正。Quan和Gibson 4根据椎弓根螺钉密度对Lenke 1型弯曲的矫正进行了量化，他们将椎弓根螺钉密度定义为整个结构中椎弓根螺钉/节段的平均数量（即，密度= 1表示平均1枚椎弓根螺钉/节段）。他们发现，无论是在每个椎弓根（密度1.75-2）还是交替椎弓根（密度1-1.25）放置螺钉，术前或术后弯曲幅度均无差异。本研究的优势在于纳入了对照组和仅具有Lenke 1型曲线的更同质的患者人群。然而，患者数量较少，根据椎弓根螺钉密度将49例患者分为4组。Deviren等人1在人体尸体模型中研究了交替椎弓根与每个椎弓根中椎弓根螺钉的放置。增加椎弓根螺钉数量导致屈曲/伸展、侧弯和旋转力矩的刚度逐渐增加，但交替和每种椎弓根策略之间的差异不显著。本研究的发现，沿着Quan和Gibson 4以及Hwang等人研究的有限临床结果，2表明，尽管该结构的生物力学性能较差，但在中度AIS患者中实现弯曲矫正和融合方面的差异并不具有临床意义。节约成本的潜力已经成为并将继续成为脊柱外科的一个重要课题，在这方面，作者应该受到赞扬。鉴于脊柱器械的高成本，脊柱外科领域在越来越关注证明增量成本效益的医疗保健环境中面临着特殊的挑战。Roach等人5最近记录了10年内治疗AIS的通货膨胀调整成本增加了100%，这几乎完全是由于椎弓根螺钉的成本。相比之下，同期治疗股骨骨折的成本仅增加了7%。Hwang等人2描述的手术策略突出了外科医生可以控制的治疗成本的一个方面。所讨论的手术技术可能被证明是骨质良好患者的一种有用策略，并且降低成本、手术时间和失血量的潜在益处值得进一步研究。为了更广泛地适用于畸形手术，该技术首先必须在其他患者人群中进行审查，其中固定点较少和骨质较弱可能比AIS人群面临更大的挑战。
Hwang et al.2 introduce a topic of interest that is potentially relevant for all surgeons who perform surgery in patients with spinal deformity. Their investigation is essentially a proof-of-concept study of a technique for reducing the number of pedicle screws used in deformity surgery by skipping every other level on the concave side and using only a few screws on the convex side of the curve. While interesting, any conclusions drawn must be limited to the study of patients with adolescent idiopathic scoliosis (AIS) because of the superior bone quality and flexible curves in that population. Other patients with spinal deformity, such as those with degenerative scoliosis, a population with poor bone quality,3,6 may not respond as well. This shortcoming is acknowledged by the authors, who defer the use of this technique in patients with large deformities or stiff curves, in which more force will be necessary to achieve and hold correction. Quan and Gibson4 quantified the correction of Lenke Type 1 curves based on pedicle screw density, which they defined as the average number of pedicle screws/ level across the construct (that is, density = 1 signifies 1 pedicle screw/level on average). They found no difference in preoperative or postoperative curve magnitude regardless of whether screws were placed at every pedicle (density 1.75–2) or alternate pedicles (density 1–1.25). The strengths of this study were the inclusion of a control group and a more homogeneous patient population with solely Lenke Type 1 curves. However, the number of patients was smaller, with 49 patients divided among 4 groups based on pedicle screw density. Deviren et al.1 investigated the placement of pedicle screws in alternate pedicles versus every pedicle in a human cadaveric model. Increasing the number of pedicle screws resulted in incrementally greater stiffness in flexion/extension, lateral bending, and rotational moments, but the differences between the alternate and every pedicle strategy were not significant. Findings in this study, along with the limited clinical results from the studies of Quan and Gibson4 and Hwang et al.,2 suggest that although this construct trends toward inferior biomechanics, the difference is not clinically significant for achieving curve correction and fusion in patients with moderate AIS. The potential for cost savings has become and will continue to be an important topic in spinal surgery, and the authors should be commended in this regard. Given the high cost of spinal instrumentation, the field of spine surgery faces a particular challenge in a health care environment that is increasingly focused on demonstrating incremental cost-effectiveness. Roach et al.5 recently documented a 100% increase in the inflation-adjusted cost of treating AIS over a 10-year period, which was due almost entirely to the cost of pedicle screws. In comparison, the cost of treating a femur fracture over the same time period increased only 7%. Surgical strategies such as those described by Hwang et al.2 highlight one aspect of treatment cost that might be controlled by the surgeon. The surgical technique discussed may prove to be a useful strategy for patients with good bone quality, and the potential benefits of reduced costs, operative times, and blood loss warrant further investigation. To be more widely applicable to deformity surgery, this technique will first have to be vetted in other patient populations in which fewer fixation points and weaker bone may present greater challenges than in the AIS population.