Biomechanics Section, KU Leuven, Leuven, Belgium; Materialise, Leuven, Belgium.
Orthopaedics Section, University Hospitals Leuven, Leuven, Belgium.
J Shoulder Elbow Surg. 2020 May;29(5):1050-1058. doi: 10.1016/j.jse.2019.10.007. Epub 2020 Jan 23.
Assessment of glenoid bone defects is important to select the optimal glenoid component design during shoulder arthroplasty planning and implantation. This study presents a fully automated method to describe glenoid bone loss using 3-dimensional measurements without the need for a healthy contralateral reference scapula.
The native shape of the glenoid is reconstructed by fitting a statistical shape model (SSM) of the scapula. The total vault loss percentage, local vault loss percentages, defect depth, defect area percentage, and subluxation distance and region are computed based on a comparison of the reconstructed and eroded glenoids. The method is evaluated by comparing its results with a contralateral bone-based reconstruction approach in a data set of 34 scapula and humerus pairs with unilateral glenoid bone defects.
The SSM-based defect measurements deviated from the contralateral bone-based measurements with mean absolute differences of 5.5% in the total vault loss percentage, 4.5% to 8.0% in the local vault loss percentages, 1.9 mm in the defect depth, 14.8% in the defect area percentage, and 1.6 mm in the subluxation distance. The SSM-based method was statistically equivalent to the contralateral bone-based method for all parameters except the defect area percentage.
The presented method is able to automatically analyze glenoid bone defects using 3-dimensional measurements without the need for a healthy contralateral bone.
在肩关节置换手术规划和植入过程中，评估肩胛骨关节盂骨缺损对于选择最佳的关节盂假体设计非常重要。本研究提出了一种全自动的方法，通过使用三维测量来描述肩胛骨关节盂骨丢失，而无需健康的对侧参考肩胛骨。
通过拟合肩胛骨的统计形状模型（SSM）来重建关节盂的原始形状。根据重建和侵蚀的关节盂之间的比较，计算总穹顶丢失百分比、局部穹顶丢失百分比、缺损深度、缺损面积百分比、半脱位距离和区域。该方法通过与单侧肩胛骨关节盂骨缺损的 34 对肩胛骨和肱骨数据集的对侧骨基重建方法进行比较来进行评估。
SSM 基于的缺陷测量值与对侧骨基测量值存在差异，总穹顶丢失百分比的平均绝对差异为 5.5%，局部穹顶丢失百分比的平均绝对差异为 4.5%至 8.0%，缺损深度的平均绝对差异为 1.9 毫米，缺损面积百分比的平均绝对差异为 14.8%，半脱位距离的平均绝对差异为 1.6 毫米。除了缺损面积百分比外，SSM 基于的方法在所有参数上均与对侧骨基方法统计学等效。
该方法能够使用三维测量自动分析肩胛骨关节盂骨缺损，而无需健康的对侧骨。
