Espinosa Norman, Dudda Marcel, Andersen Jason, Bernardi Mark, Kasser James R
Department of Orthopaedics, Children's Hospital, Boston, MA 02115, USA.
Foot Ankle Int. 2008 Feb;29(2):205-12. doi: 10.3113/FAI.2008.0205.
Calcaneonavicular coalitions (CNC) have been reported to be associated with anatomical aberrations of either the calcaneus and/or navicular bones. These morphological abnormalities may complicate accurate surgical resection. Three-dimensional analysis of spatial orientation and morphological characteristics may help in preoperative planning of resection.
Sixteen feet with a diagnosis of CNC were evaluated by means of 3-D CT modeling. Three angles were defined that were expressed in relation to one reproducible landmark (lateral border of the calcaneus): the dorsoplantar inclination, anteroposterior inclination, and socket angle. The depth and width of the coalitions were measured and calculated to obtain the estimated contact surface. Three-dimensional reconstructions of the calcanei served to evaluate the presence, distortion or absence of the anterior calcaneal facet and presence of a navicular beak. The interrater correlations were assessed in order to obtain values for the accuracy of the measurement methods. Sixteen normal feet were used as controls for comparison of the socket angle; anatomy of the anterior calcaneal facet and navicular beak as well.
The dorsoplantar inclination angle averaged 50 degrees (+/-17), the anteroposterior inclination angle 64 degrees (+/-15), and the pathologic socket angle 98 degrees (+/-11). The average contact area was 156 mm(2). Ninety-four percent of all patients in the CNC group revealed a plantar navicular beak. In 50% of those patients the anterior calcaneal facet was replaced by the navicular portion and in 44% the facet was totally missing. In contrast, the socket angle in the control group averaged 77 degrees (+/-18), which was found to be statistically different than the CNC group (p = 0.0004). Only 25% of the patients in the control group had a plantar navicular beak. High, statistically significant interrater correlations were found for all measured angles.
Computer-aided CT analysis and reconstructions help to determine the spatial orientations of CNC in space and provide useful information in order to anticipate morphological abnormalities of the calcaneus and navicular.
据报道，跟舟联合（CNC）与跟骨和/或舟骨的解剖变异有关。这些形态异常可能会使准确的手术切除复杂化。对空间方向和形态特征进行三维分析可能有助于手术切除的术前规划。
通过三维CT建模对16例诊断为CNC的足部进行评估。定义了三个与一个可重复的标志点（跟骨外侧缘）相关的角度：背跖倾斜角、前后倾斜角和窝角。测量并计算联合的深度和宽度以获得估计的接触面积。跟骨的三维重建用于评估跟骨前关节面的存在、变形或缺失以及舟骨喙的存在。评估了评分者间的相关性，以获得测量方法准确性的值。使用16例正常足部作为对照组，比较窝角；以及跟骨前关节面和舟骨喙的解剖结构。
背跖倾斜角平均为50度（±17），前后倾斜角为64度（±15），病理性窝角为98度（±11）。平均接触面积为156平方毫米。CNC组所有患者中有94%显示有足底舟骨喙。在这些患者中，50%的跟骨前关节面被舟骨部分取代，44%的关节面完全缺失。相比之下，对照组的窝角平均为77度（±18），发现与CNC组有统计学差异（p = 0.0004）。对照组中只有25%的患者有足底舟骨喙。所有测量角度均发现评分者间具有高度统计学显著的相关性。
计算机辅助CT分析和重建有助于确定CNC在空间中的空间方向，并提供有用信息以预测跟骨和舟骨的形态异常。
