Department of Orthopaedics and Traumatology, Paracelsus Medical University, Salzburg, Austria; Roth|McFarlane Hand and Upper Limb Centre, St Joseph's Hospital, London, ON, Canada.
Roth|McFarlane Hand and Upper Limb Centre, St Joseph's Hospital, London, ON, Canada; School of Biomedical Engineering, Western University, London, ON, Canada.
J Shoulder Elbow Surg. 2020 Jul;29(7):1460-1469. doi: 10.1016/j.jse.2019.11.009. Epub 2020 Feb 12.
The purpose of this study was 2-fold: (1) to quantify type E2 bone loss orientation and its association with rotator cuff fatty infiltration and (2) to examine reverse baseplate designs used to manage type E2 glenoids.
Computed tomography scans of 40 patients with type E2 glenoids were examined for pathoanatomic features and erosion orientation. The rotator cuff fatty infiltration grade was compared with the erosion orientation angle. To compare reconstructive options in light of the pathoanatomic findings, virtual implantation of 4 glenoid baseplate designs (standard, half wedge, full wedge, and patient-matched) was conducted to determine the volume of bone removal for seating and impingement-free range of motion.
The mean type E2 erosion orientation angle was 47° ± 17° from the 0° superoinferior glenoid axis, resulting in the average erosion being located in the posterosuperior quadrant directed toward the 10:30 clock-face position. The type E2 neoglenoid, on average, involved 67% of the total glenoid surface (total surface area, 946 ± 209 mm; neoglenoid surface area, 636 ± 247 mm). The patient-matched baseplate design resulted in significantly (P ≤ .01) less bone removal (200 ± 297 mm) for implantation, followed by the full-wedge design (1228 ± 753 mm), half-wedge design (1763 ± 969 mm), and standard (non-augmented) design (4009 ± 1210 mm). We noted a marked difference in erosion orientation toward a more superior direction as the subscapularis fatty infiltration grade increased from grade 3 to grade 4 (P < .001).
The average type E2 erosion orientation was directed toward the 10:30 clock-face position in the posterosuperior glenoid quadrant. This orientation resulted in the patient-matched glenoid augmentation requiring the least amount of bone removal for seating, followed by the full-wedge, half-wedge, and standard designs. Implant selection also substantially affected computationally derived range of motion in external rotation, flexion, extension, and adduction.
本研究旨在实现两个目标：（1）量化 E2 型骨丢失的方向及其与肩袖脂肪浸润的关系；（2）研究用于处理 E2 型肩盂的反向基底设计。
对 40 例 E2 型肩盂患者的 CT 扫描进行检查，以确定其病理解剖特征和侵蚀方向。比较肩袖脂肪浸润程度与侵蚀方向角度。为了根据病理解剖发现比较重建方案，对 4 种肩盂基底设计（标准型、半楔形、全楔形和患者匹配型）进行了虚拟植入，以确定为实现关节面接触和无撞击运动范围所需的骨切除量。
E2 型侵蚀的平均方向角度为距 0°上下盂肱轴 47°±17°，导致平均侵蚀位于后上方，朝向 10：30 时钟位置。E2 型新盂肱关节平均累及总盂肱关节表面的 67%（总表面积为 946±209mm；新盂肱关节表面积为 636±247mm）。患者匹配型基底设计植入所需的骨切除量明显较少（200±297mm），其次是全楔形设计（1228±753mm）、半楔形设计（1763±969mm）和标准（非增强）设计（4009±1210mm）。我们注意到，随着肩胛下肌脂肪浸润程度从 3 级增加到 4 级，侵蚀方向明显向更上方的方向变化（P<.001）。
E2 型平均侵蚀方向指向后上方盂肱关节象限的 10：30 时钟位置。这种方向导致患者匹配的盂肱关节增强所需的骨切除量最少，其次是全楔形、半楔形和标准设计。植入物选择还会显著影响外旋、屈曲、伸展和内收的计算运动范围。
