Global Alignment and Proportion (GAP) Score Development and Validation of a New Method of Analyzing Spinopelvic Alignment to Predict Mechanical Complications After Adult Spinal Deformity Surgery
Global Alignment and Proportion (GAP) Score Development and Validation of a New Method of Analyzing Spinopelvic Alignment to Predict Mechanical Complications After Adult Spinal Deformity Surgery
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DOI：
10.2106/jbjs.16.01594
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发表时间：
2017-10-04
影响因子：
5.3
通讯作者：
Alanay, Ahmet
中科院分区：
文献类型：
--
作者：
Yilgor, Caglar;Sogunmez, Nuray;Alanay, Ahmet
背景资料：恢复正常的矢状面对线是成人脊柱畸形手术的一个关键目标，以获得良好的结果并防止机械并发症。Schwab矢状面调节器已被接受为适当对线的目标，但解决这些目标并不总是能防止高机械并发症或翻修率。这可能是因为线性绝对数值参数未涵盖整个骨盆发病率谱，并且前凸、骨盆前倾和负对线不良的分布未被视为潜在失效原因。本研究的目的是开发和验证一个评分的基础上骨盆发病率为基础的比例参数，以更好地预测机械complications.Methods：222例患者（168名女性和54名男性），随访>= 2年后，在>= 4个级别的后路融合纳入本研究。平均年龄（和标准差）为52.2 ± 19.3岁（范围：18 - 84岁），平均随访时间为28.8 ± 8.2个月（范围：24 - 62个月）。在随机分配至推导（n = 148，66.7%）和验证（n = 74，33.3%）队列的患者组中开发并验证了总体对齐和比例（GAP）评分。GAP评分参数为相对骨盆倾斜度（测量值减去理想骶骨倾斜度）、相对腰椎前凸（测量值减去理想腰椎前凸度）、前凸分布指数（L4-S1前凸度除以L1-S1前凸度乘以100）、相对脊柱骨盆对线（测量值减去理想整体倾斜度）和年龄因素。近端和远端交界处脊柱后凸和/或失效、棒断裂和其他植入物相关并发症被视为机械并发症。采用受试者工作特征（ROC）分析法分析差距评分的预测准确性。GAP类别和机械并发症和修订之间的关联进行了分析，使用Cochran-Armitage tests.Results：在验证队列中，32例（43%）经历了机械并发症和17例（23%）进行了机械修订。差距评分预测机械并发症的曲线下面积为0.92（标准误[SE] = 0.034，p < 0.001，95% [置信区间[CI] = 0.85 - 0.98）。术后，根据差距评分，脊柱骨盆状态成比例的患者的机械并发症发生率为6%，而中度或重度脊柱骨盆状态的患者的机械并发症发生率分别为47%和95%。差距评分是一种新的骨盆发病率-基于比例的矢状面分析方法预测成人脊柱手术患者的机械并发症畸形根据差距评分设定手术目标可降低机械并发症的发生率。
Background: The restoration of normal sagittal alignment is a critical goal in adult spinal deformity surgery to achieve favorable outcomes and prevent mechanical complications. Schwab sagittal modifiers have been accepted as targets for appropriate alignment, but addressing these targets does not always prevent high mechanical complication or revision rates. This may be because the linear absolute numerical parameters do not cover the whole pelvic incidence spectrum and the distribution of lordosis, pelvic anteversion, and negative malalignment are not considered as potential causes of failure. The aim of the present study was to develop and validate a score based on pelvic-incidence-based proportional parameters to better predict mechanical complications.Methods: Two hundred and twenty-two patients (168 women and 54 men) followed for >= 2 years after posterior fusion at >= 4 levels were included in the study. The mean age (and standard deviation) was 52.2 +/- 19.3 years (range, 18 to 84 years), and the mean duration of follow-up was 28.8 +/- 8.2 months (range, 24 to 62 months). The global alignment and proportion (GAP) score was developed and validated in groups of patients randomly assigned to derivation (n = 148, 66.7%) and validation (n = 74, 33.3%) cohorts. GAP score parameters were relative pelvic version (the measured minus the ideal sacral slope), relative lumbar lordosis (the measured minus the ideal lumbar lordosis), lordosis distribution index (the L4-S1 lordosis divided by the L1-S1 lordosis multiplied by 100), relative spinopelvic alignment (the measured minus the ideal global tilt), and an age factor. Proximal and distal junctional kyphosis and/or failure, rod breakage, and other implant-related complications were considered mechanical complications. The predictive accuracy of the GAP score was analyzed using receiver operating characteristic (ROC) analyses. Associations between GAP categories and mechanical complications and revisions were analyzed using Cochran-Armitage tests.Results: In the validation cohort, 32 patients (43%) experienced mechanical complications and 17 (23%) underwent mechanical revision. The area under curve for the GAP score predicting mechanical complications was 0.92 (standard error [SE] = 0.034, p < 0.001, 95% [confidence interval [CI] = 0.85 to 0.98). Postoperatively, patients with a proportioned spinopelvic state according to the GAP score had a mechanical complication rate of 6% while those with a moderately or severely disproportioned spinopelvic state had rates of 47% and 95%, respectively.Conclusions: The GAP score is a new pelvic-incidence-based proportional method of analyzing the sagittal plane that predicts mechanical complications in patients undergoing surgery for adult spinal deformity. Setting surgical goals according to the GAP score may decrease the prevalence of mechanical complications.