Krejčí J, Gallo J, Salinger J, Štěpaník P
Katedra přírodních věd v kinantropologii, FTK UP Olomouc.
Acta Chir Orthop Traumatol Cech. 2012;79(3):255-62.
Repeated measurements of the spine are absolutely necessary in children and adolescents affected by spinal deformities especially during their growing-up periods. To avoid risks of tissue damage from x-ray exposure, several methods for non-invasive measurement of the spinal curvature have been developed. One of them is the DTP-3 position system allowing for a three-dimensional measurement of anatomical landmarks (spinous processes) and the calculation of curvature angles in both the frontal and sagittal planes. We were interested to know whether the DTP-3 was precise enough to determine the true spinal curvature.
To determine the precision of the DTP-3 system, we constructed a model of the spine. The model was then repeatedly investigated by both the noninvasive and x-ray methods. The distortion of x-ray images caused by the central projection mechanism was considered and included in the calculation. In addition, a group of patients with scoliosis up to 40° was evaluated by both the DTP-3 system and x-ray (the latter according to Cobb's method).
Differences in spatial coordinates between DTP-3 and x-ray examinations reached 20.9 mm in the frontal plane and 67.3 mm in the sagittal plane without distortion correction of x-ray images. The differences decreased below 1.5 mm after image distortion correction in each plane. Distortion correction had not the same effect for angle parameters as for coordinates. Differences between the DTP-3 angle parameters and Cobb's x-ray angles were below 4.7°, both without correction and after correction. The difference between DTP-3 angle parameters and Cobb's x-ray angles was -1.8° ± 3.0° (mean ± standard deviation) when measurement was performed on the patients with scoliosis.
The goal of any clinical examination is to obtain data applicable to decision-making analysis. In the case of scoliosis it is necessary to report results in terms of Cobb's angle, which is the problem for all surface-dependent methods, especially in patients with double curves. A solution may be to define the maximal difference between noninvasive and x-ray methods that could be acceptable for good clinical practice.
In this study we report good concordance between noninvasive and x-ray examinations of a modeled spinal deformity in terms of both angle and linear measurements. The same results were obtained for angle measurements in a group of patients with scoliosis up to 40°. Based on this study and our previous data we believe that the DTP-3 system can be introduced into clinical practice.
对于患有脊柱畸形的儿童和青少年，尤其是在其生长发育阶段，对脊柱进行重复测量是绝对必要的。为避免X射线照射造成组织损伤的风险，已开发出几种用于脊柱弯曲度非侵入性测量的方法。其中一种是DTP - 3定位系统，它可以对解剖标志（棘突）进行三维测量，并计算额状面和矢状面的弯曲角度。我们想了解DTP - 3是否精确到足以确定真实的脊柱弯曲度。
为确定DTP - 3系统的精度，我们构建了一个脊柱模型。然后分别用非侵入性方法和X射线方法对该模型进行反复研究。考虑并将由中心投影机制引起的X射线图像失真纳入计算。此外，对一组侧弯角度达40°的脊柱侧弯患者同时采用DTP - 3系统和X射线（后者按照Cobb法）进行评估。
在未对X射线图像进行失真校正时，DTP - 3检查与X射线检查在空间坐标上的差异在额状面达20.9毫米，在矢状面达67.3毫米。在对每个平面的图像进行失真校正后，差异降至1.5毫米以下。失真校正对角度参数的影响与对坐标的影响不同。无论是否校正，DTP - 3角度参数与Cobb法X射线角度之间的差异均低于4.7°。对脊柱侧弯患者进行测量时，DTP - 3角度参数与Cobb法X射线角度之间的差异为-1.8°±3.0°（均值±标准差）。
任何临床检查的目标都是获取适用于决策分析的数据。对于脊柱侧弯，有必要按照Cobb角报告结果，这是所有依赖体表的方法都存在的问题，尤其是对于双弯患者。一个解决方案可能是定义非侵入性方法与X射线方法之间在良好临床实践中可接受的最大差异。
在本研究中，我们报告了在角度和线性测量方面，对模拟脊柱畸形进行非侵入性检查与X射线检查之间具有良好的一致性。对于一组侧弯角度达40°的脊柱侧弯患者的角度测量也得到了相同结果。基于本研究及我们之前的数据，我们认为DTP - 3系统可引入临床实践。
