Joint Replacement Center, Eunpyeong St. Mary's Hospital, Seoul 03312, Korea.
Department of Orthopaedic Surgery, College of Medicine, The Catholic University of Korea, Seoul 06591, Korea.
Medicina (Kaunas). 2022 Aug 11;58(8):1085. doi: 10.3390/medicina58081085.
Introduction: Adequate bone quality is essential for long term biologic fixation of cementless total knee arthroplasty (TKA). Recently, vertebral bone quality evaluation using dual-energy computed tomography (DECT) has been introduced. However, the DECT bone mineral density (BMD) in peripheral skeleton has not been correlated with Hounsfield units (HU) or central dual-energy X-ray absorptiometry (DXA), and the accuracy remains unclear. Materials and methods: Medical records of 117 patients who underwent TKA were reviewed. DXA was completed within three months before surgery. DECT was performed with third-generation dual source CT in dual-energy mode. Correlations between DXA, DECT BMD and HU for central and periarticular regions were analyzed. Receiver operating characteristic (ROC) curves were plotted and area under the curve (AUC), optimal threshold, and sensitivity and specificity of each region of interest (ROI) were calculated. Results: Central DXA BMD was correlated with DECT BMD and HU in ROIs both centrally and around the knee (all p < 0.01). The diagnostic accuracy of DECT BMD was higher than that of DECT HU and was also higher when the T-score for second lumbar vertebra (L2), rather than for the femur neck, was used as the reference standard (all AUC values: L2 > femur neck; DECT BMD > DECT HU, respectively). Using the DXA T-score at L2 as the reference standard, the optimal DECT BMD cut-off values for osteoporosis were 89.2 mg/cm3 in the distal femur and 78.3 mg/cm3 in the proximal tibia. Conclusion: Opportunistic volumetric BMD assessment using DECT is accurate and relatively simple, and does not require extra equipment. DECT BMD and HU are useful for osteoporosis screening before cementless TKA.
对于非骨水泥全膝关节置换术（TKA）的长期生物学固定，足够的骨质量至关重要。最近，已经引入了使用双能计算机断层扫描（DECT）评估椎骨质量的方法。但是，外周骨骼的 DECT 骨矿物质密度（BMD）尚未与 Hounsfield 单位（HU）或中央双能 X 射线吸收法（DXA）相关联，其准确性仍不清楚。
回顾了 117 例行 TKA 的患者的病历。DXA 在手术前三个月内完成。DECT 使用第三代双源 CT 在双能量模式下进行。分析了 DXA，DECT BMD 和中央及关节周围区域的 HU 之间的相关性。绘制了接收者操作特征（ROC）曲线，并计算了每个感兴趣区域（ROI）的曲线下面积（AUC）、最佳阈值以及灵敏度和特异性。
中央 DXA BMD 与中央和膝关节周围 ROI 的 DECT BMD 和 HU 相关（均 P <0.01）。DECT BMD 的诊断准确性高于 DECT HU，并且当将第二腰椎（L2）的 T 评分而不是股骨颈的 T 评分用作参考标准时，诊断准确性更高（所有 AUC 值：L2 >股骨颈；DECT BMD > DECT HU）。当以 L2 的 DXA T 评分作为参考标准时，股骨远端和胫骨近端骨质疏松的最佳 DECT BMD 截断值分别为 89.2 mg/cm3 和 78.3 mg/cm3。
使用 DECT 进行机会性容积 BMD 评估准确且相对简单，并且不需要额外的设备。DECT BMD 和 HU 可用于非骨水泥 TKA 前的骨质疏松症筛查。
