Koo Terry K K, Papuga M Owen
Foot Levelers Biomechanics Research Laboratory, Department of Research, New York Chiropractic College, Seneca Falls, New York, USA.
Comput Aided Surg. 2009;14(1-3):45-57. doi: 10.3109/10929080903016102.
A computer aided method for closed tibial shaft fracture reduction based on measurements of 12 projection parameters (6 angulations and 6 translations) from an anteroposterior radiograph, a lateral radiograph, and a transverse projection photograph is examined. The development, validation and reliability of the computer aided method are presented. A custom-made unilateral external fixation device consisting of 7 calibrated one-degree-of-freedom joints was employed to execute the reduction. Five tibial fracture phantoms with initial deformities that covered a wide range of misalignments were tested. The mean (standard deviation) resultant rotational and translational errors after the reduction were 3.32° (0.96°) and 1.65 (0.86) mm, respectively, which indicates good reduction accuracy. Three independent raters made the measurements of the projection parameters to test inter-rater reliability. The intra-class correlation coefficients were found to range between 0.935 and 1, indicating good reliability. Since ideal patient positioning for AP, lateral and transverse image acquisition is not easily attainable, the effect of patient positioning errors on the measurement of projection parameters was explored using a tibial phantom. The preliminary results revealed that 10° deviations in positioning do not greatly affect the measurement of AP and lateral angulation parameters (<1.7°). However, a 10° positioning error about the long bone axis may result in a change of as much as 10.7° in the measurements of transverse projection angulation parameters. In addition, a 10° positioning error about an arbitrary anatomical axis may result in translational projection parameter changes of up to 6.8 mm. For these reasons, a previously validated method that allows for accurate positioning of the tibia about its long axis and a two-step reduction strategy to achieve the best possible deformity reduction are proposed. Procedures to facilitate reliable measurement of tibial torsion are also discussed. It appears that the projection-based reduction method exposes the patient to less radiation and allows for simple, quick and accurate reductions, making it an attractive choice for acute clinical applications.
本文研究了一种基于前后位X线片、侧位X线片和横向投影照片的12个投影参数（6个角度和6个平移）测量的计算机辅助闭合性胫骨干骨折复位方法。介绍了该计算机辅助方法的开发、验证和可靠性。采用一种由7个校准的单自由度关节组成的定制单侧外固定装置进行复位。测试了5个具有初始畸形且涵盖广泛错位范围的胫骨骨折模型。复位后平均（标准差）旋转和平移误差分别为3.32°（0.96°）和1.65（0.86）mm，表明复位精度良好。由三名独立评估者测量投影参数以测试评估者间的可靠性。组内相关系数在0.935至1之间，表明可靠性良好。由于难以实现用于前后位、侧位和横向图像采集的理想患者体位，因此使用胫骨模型探讨了患者体位误差对投影参数测量的影响。初步结果显示，体位偏差10°对前后位和侧位角度参数的测量影响不大（<1.7°）。然而，沿长骨轴10°的体位误差可能导致横向投影角度参数测量变化高达10.7°。此外，沿任意解剖轴10°的体位误差可能导致平移投影参数变化高达6.8 mm。基于这些原因，提出了一种先前经过验证的方法，该方法允许胫骨沿其长轴进行精确定位，并采用两步复位策略以实现尽可能好的畸形复位。还讨论了便于可靠测量胫骨扭转的程序。基于投影的复位方法似乎使患者受到的辐射较少，并且允许进行简单、快速和准确的复位，使其成为急性临床应用的一个有吸引力的选择。
