Martin Elise J, Duquin Thomas R, Ehrensberger Mark T
Department of Biomedical Engineering, State University of New York at Buffalo, Buffalo, New York.
Department of Orthopaedic Surgery, State University of New York at Buffalo, Buffalo, New York.
J Shoulder Elb Arthroplast. 2021 Jun 13;5:24715492211020689. doi: 10.1177/24715492211020689. eCollection 2021.
Glenoid bone loss is commonly encountered in cases of rotator cuff tear arthropathy and can create challenges during reverse shoulder arthroplasty. In this study, we sought to investigate the biomechanical properties of a new treatment option for superior glenoid defect, an augmented reverse total shoulder baseplate.
Three conditions were examined: non-augmented baseplate without defect, non-augmented baseplate with defect, and augmented baseplate with defect. The augmented baseplates included a 30-degree half wedge which also matched the created superior defect. The samples were cyclically loaded at a 60 simulated abduction angle to mimic baseplate loosening. The migration and micromotion of the baseplate were measured on the superior edge using a 3D Digital Image Correlation System.
The migration measured in the augmented baseplate showed no significant difference when compared to the no defect or defect cases. In terms of micromotion, the augmented baseplate showed values that were between the micromotions reported for the no defect and defect conditions, but not by a statistically significant amount.
This study provides biomechanical evidence that augmented baseplates can reduce the amount of micromotion experienced by the RSA construct in the presence of significant superior glenoid bone deficiency, but do not fully restore stability to that of a full contact non-augmented baseplate.
盂肱关节骨质流失在肩袖撕裂性关节病病例中较为常见，在进行反式肩关节置换术时会带来挑战。在本研究中，我们试图研究一种针对肩胛盂上极缺损的新治疗方案——增强型反式全肩关节基板的生物力学特性。
研究了三种情况：无缺损的非增强型基板、有缺损的非增强型基板和有缺损的增强型基板。增强型基板包括一个30度的半楔形，其也与所造成的上极缺损相匹配。样本在60°模拟外展角度下进行循环加载，以模拟基板松动。使用三维数字图像相关系统在上边缘测量基板的移位和微动。
与无缺损或有缺损的情况相比，增强型基板测量的移位无显著差异。在微动方面，增强型基板显示的值介于无缺损和有缺损情况下报告的微动值之间，但差异无统计学意义。
本研究提供了生物力学证据，表明在存在明显肩胛盂上极骨缺损的情况下，增强型基板可减少反式肩关节置换术结构所经历的微动，但不能完全恢复到全接触非增强型基板的稳定性。
