Department of Radiology, University of Pennsylvania, Philadelphia, PA.
Department of Orthopaedic Surgery, University of Pennsylvania, Philadelphia, PA.
Spine (Phila Pa 1976). 2020 Sep 1;45(17):1208-1214. doi: 10.1097/BRS.0000000000003504.
Case-control study.
The objective of this study was to identify the best laboratory and imaging factors to predict bone biopsy culture positivity in the setting of vertebral discitis/osteomyelitis (VDO).
Good predictors of bone biopsy culture positivity in the setting of VDO are unknown.
Retrospective review was performed for 46 patients who underwent CT-guided bone biopsy for the evaluation of clinically confirmed VDO. Erythrocyte sedimentation rate, C-reactive protein (CRP), mean CT attenuation of the biopsied bone, and the change in the CT attenuation of the bone compared to unaffected vertebral bone (delta CT attenuation) were measured. Receiver-operator characteristic curve analyses were performed to identify the optimal threshold value for each variable. A multivariable logistic regression model was used to predict the probability of a positive bone culture using delta CT attenuation and CRPx100% fold above normal.
For one of the 46 VDO patients, bone cultures were not obtained. Approximately 35.6% (16/45) of bone cultures were positive. The most significant predictors of bone culture positivity were CRP x100% fold above normal (P = 0.011) and delta CT attenuation (P = <0.001). Optimized predictive thresholds were calculated to be CRP 4-fold above normal reference value (90.9% sensitivity, 73.7% specificity), or if the CT attenuation of the affected vertebral body was >25.9 HU lower relative to unaffected bone (93.8% sensitivity, 75.0% specificity).
Delta CT attenuation, as well as CRP level over four times the upper limits of normal, were the strongest predictors for bone culture positivity in patients with VDO.
病例对照研究。
本研究旨在确定预测椎间盘炎/骨髓炎（VDO）背景下骨活检培养阳性的最佳实验室和影像学因素。
VDO 背景下骨活检培养阳性的良好预测因子尚不清楚。
对 46 例经 CT 引导下骨活检确诊为 VDO 的患者进行回顾性分析。测量红细胞沉降率（ESR）、C 反应蛋白（CRP）、活检骨的平均 CT 衰减值以及与未受影响的椎体骨相比（delta CT attenuation）的骨 CT 衰减值变化。进行受试者工作特征曲线分析以确定每个变量的最佳阈值值。使用 delta CT 衰减和 CRP 超过正常水平 100%的倍数，采用多变量逻辑回归模型预测骨培养阳性的概率。
在 46 例 VDO 患者中，有 1 例未获得骨培养。大约 35.6%（16/45）的骨培养呈阳性。骨培养阳性的最显著预测因子是 CRP 超过正常水平的 100%（P=0.011）和 delta CT 衰减（P<0.001）。计算出的最佳预测阈值为 CRP 高于正常参考值的 4 倍（90.9%的敏感性，73.7%的特异性），或者受影响的椎体的 CT 衰减值比未受影响的骨低 25.9 HU 以上（93.8%的敏感性，75.0%的特异性）。
在 VDO 患者中，delta CT 衰减以及 CRP 水平超过正常上限的 4 倍是骨培养阳性的最强预测因子。
3。
