Schulthess Clinic, Zurich, Switzerland.
Arthrex, Naples, Florida, USA.
Bone Joint J. 2024 Nov 1;106-B(11):1284-1292. doi: 10.1302/0301-620X.106B11.BJJ-2024-0110.R1.
The objective of this study was to compare simulated range of motion (ROM) for reverse total shoulder arthroplasty (rTSA) with and without adjustment for scapulothoracic orientation in a global reference system. We hypothesized that values for simulated ROM in preoperative planning software with and without adjustment for scapulothoracic orientation would be significantly different.
A statistical shape model of the entire humerus and scapula was fitted into ten shoulder CT scans randomly selected from 162 patients who underwent rTSA. Six shoulder surgeons independently planned a rTSA in each model using prototype development software with the ability to adjust for scapulothoracic orientation, the starting position of the humerus, as well as kinematic planes in a global reference system simulating previously described posture types A, B, and C. ROM with and without posture adjustment was calculated and compared in all movement planes.
All movement planes showed significant differences when comparing protocols with and without adjustment for posture. The largest mean difference was seen in external rotation, being 62° (SD 16°) without adjustment compared to 25° (SD 9°) with posture adjustment (p < 0.001), with the highest mean difference being 49° (SD 15°) in type C. Mean extension was 57° (SD 18°) without adjustment versus 24° (SD 11°) with adjustment (p < 0.001) and the highest mean difference of 47° (SD 18°) in type C. Mean abducted internal rotation was 69° (SD 11°) without adjustment versus 31° (SD 6°) with posture adjustment (p < 0.001), showing the highest mean difference of 51° (SD 11°) in type C.
The present study demonstrates that accounting for scapulothoracic orientation has a significant impact on simulated ROM for rTSA in all motion planes, specifically rendering vastly lower values for external rotation, extension, and high internal rotation. The substantial differences observed in this study warrant a critical re-evaluation of all previously published studies that examined component choice and placement for optimized ROM in rTSA using conventional preoperative planning software.
本研究旨在比较在全局参考系中，考虑和不考虑肩胛胸廓取向对反式全肩关节置换术（rTSA）模拟活动度（ROM）的影响。我们假设，在术前规划软件中，考虑和不考虑肩胛胸廓取向对模拟 ROM 的影响值会有显著差异。
通过对 162 例接受 rTSA 的患者的 10 例肩部 CT 扫描进行拟合，构建了完整肱骨和肩胛骨的统计形状模型。6 名肩关节外科医生在每个模型中使用原型开发软件进行独立规划，该软件具有调整肩胛胸廓取向、肱骨起始位置以及在全局参考系中模拟先前描述的 A、B 和 C 体位类型的运动平面的能力。在所有运动平面中计算并比较了考虑和不考虑体位调整的 ROM。
在比较考虑和不考虑体位调整的方案时，所有运动平面均显示出显著差异。在不考虑体位调整时，外旋的平均差异最大，为 62°（SD 16°），而考虑体位调整时为 25°（SD 9°）（p<0.001），其中 C 型的平均差异最大，为 49°（SD 15°）。不考虑体位调整时的平均伸展为 57°（SD 18°），考虑体位调整时为 24°（SD 11°）（p<0.001），其中 C 型的平均差异最大，为 47°（SD 18°）。不考虑体位调整时的平均内收内旋为 69°（SD 11°），考虑体位调整时为 31°（SD 6°）（p<0.001），其中 C 型的平均差异最大，为 51°（SD 11°）。
本研究表明，考虑肩胛胸廓取向对 rTSA 在所有运动平面上的模拟 ROM 有显著影响，特别是使外旋、伸展和高内旋的数值显著降低。本研究观察到的显著差异，要求对所有使用传统术前规划软件评估 rTSA 优化 ROM 时组件选择和放置的先前发表的研究进行批判性重新评估。
