Department of Orthopaedic Surgery, The Johns Hopkins University, Baltimore, Maryland.
Department of Neurosurgery, University of British Columbia, Vancouver, British Columbia, Canada.
Neurosurgery. 2018 Jun 1;82(6):847-853. doi: 10.1093/neuros/nyx303.
A surgical invasiveness index (SII) has been validated in general spine procedures but not adult spinal deformity (ASD).
To assess the ability of the SII to determine the invasiveness of ASD surgery and to create and validate a novel ASD index incorporating deformity-specific factors, which could serve as a standardized metric to compare outcomes and risk stratification of different ASD procedures for a given deformity.
Four hundred sixty-four patients who underwent ASD surgery between 2009 and 2012 were identified in 2 multicenter prospective registries. Multivariable models of estimated blood loss (EBL) and operative time were created using deformity-specific factors. Beta coefficients derived from these models were used to attribute points to each component. Scoring was iteratively refined to determine the R2 value of multivariate models of EBL and operative time using adult spinal deformity-surgical (ASD-S) as an independent variable. Similarly, we determined weighting of postoperative changes in radiographical parameters, which were incorporated into another index (adult spinal deformity-surgical and radiographical [ASD-SR]). The ability of these models to predict surgical invasiveness was assessed in a validation cohort.
Each index was a significant, independent predictor of EBL and operative time (P < .001). On multivariate analysis, ASD-S and ASD-SR explained more variability in EBL and operative time than did the SII (P < .001). The ASD-SR explained 21% of the variation in EBL and 10% of the variation in operative time, whereas the SII explained 17% and 3.2%, respectively.
The ASD-SR, which incorporates deformity-specific components, more accurately predicts the magnitude of ASD surgery than does the SII.
手术侵袭指数（SII）已在一般脊柱手术中得到验证，但尚未在成人脊柱畸形（ASD）中得到验证。
评估 SII 确定 ASD 手术侵袭性的能力，并创建和验证一种新的 ASD 指数，该指数纳入了特定于畸形的因素，可以作为一种标准化指标，用于比较给定畸形的不同 ASD 手术的结果和风险分层。
在 2 个多中心前瞻性登记处中确定了 2009 年至 2012 年期间接受 ASD 手术的 464 名患者。使用特定于畸形的因素创建了估计失血量（EBL）和手术时间的多变量模型。从这些模型中得出的β系数用于为每个组成部分分配分数。通过迭代细化评分，使用成人脊柱畸形手术（ASD-S）作为独立变量，确定 EBL 和手术时间的多变量模型的 R2 值。同样，我们确定了术后影像学参数变化的权重，这些参数被纳入另一个指数（成人脊柱畸形手术和影像学[ASD-SR]）中。在验证队列中评估了这些模型预测手术侵袭性的能力。
每个指数都是 EBL 和手术时间的显著独立预测因子（P <.001）。在多变量分析中，ASD-S 和 ASD-SR 比 SII 更能解释 EBL 和手术时间的变异性（P <.001）。ASD-SR 解释了 EBL 变化的 21%和手术时间变化的 10%，而 SII 分别解释了 17%和 3.2%。
ASD-SR 纳入了特定于畸形的成分，比 SII 更能准确预测 ASD 手术的程度。
