Department of Mechanical and Materials Engineering, Western University, London, ON, Canada; Roth | McFarlane Hand and Upper Limb Centre, St Joseph's Health Care, London, ON, Canada.
Roth | McFarlane Hand and Upper Limb Centre, St Joseph's Health Care, London, ON, Canada.
J Shoulder Elbow Surg. 2024 Nov;33(11):2482-2492. doi: 10.1016/j.jse.2024.04.030. Epub 2024 Jun 21.
Accurate insertion of the glenoid guide pin in shoulder arthroplasty (RSA) is important for obtaining optimized glenoid component position and orientation. The objective of this study was to evaluate and compare the accuracy of 3 glenoid guide pin insertion techniques: (1) traditional software planning using freehand guide pin insertion (freehand), (2) guide pin insertion utilizing patient-specific instrumentation (PSI), and (3) using a mixed-reality navigation (MR-NAV) system.
Twenty (20) computed tomography (CT) scans were obtained from patients exhibiting glenoid erosion patterns according to the Walch and Favard classifications. Cases were planned using validated 3-dimensional (3D) preoperative planning software. The CT data were then used to 3D print triplicate plastic models of each glenoid to evaluate the 3 guide pin insertion techniques. The first technique employed traditional software planning with freehand guide pin insertion. The second method used preoperatively planned PSI guides, whereas the third used an MR-NAV system, which provided real-time holographic guidance during guide pin insertion. Once all guide pins had been inserted into the models, an independent optical tracking system and custom digitization device was used to quantify the position and orientation of each guide pin relative to the glenoid. The outcomes for this study included the absolute mean error in guide pin inclination, version, and entry point relative to the preoperative plan. The absolute Total Global Error was also assessed, which was defined as the sum of the absolute guide pin orientation and position error relative to the preoperative plan.
No statistically significant differences between MR-NAV and PSI were found for the inclination error (2° ± 1° vs. 2° ± 1°; P = .056), version error (1° ± 1° vs. 1° ± 1°; P > .99), and Total Global Error (5 ± 1 [mm + deg] vs. 5 ± 1 [mm + deg], P > .99), respectively. The freehand technique produced significantly greater error than MR-NAV and PSI for inclination (5° ± 3°, P ≤ .017), version (4° ± 3°, P ≤ .032), and Total Global Error (8 ± 3 [mm + deg], P < .001). No statistically significant differences in the entry point error were observed between all guide pin insertion methods (P ≥ .058).
These results demonstrate that the precision and accuracy of MR-NAV is comparable to PSI and superior to a freehand technique for glenoid guide pin insertion in vitro. Further study is needed to compare the accuracy of these techniques intraoperatively, in addition to assessing a potential learning curve between surgeons of varying experience with the MR-NAV system.
在肩关节置换术中（RSA），准确插入肩胛盂导针对于获得优化的肩胛盂假体位置和方向非常重要。本研究的目的是评估和比较 3 种肩胛盂导针插入技术的准确性：（1）传统软件规划结合徒手导针插入（徒手），（2）使用患者特异性器械（PSI）插入导针，以及（3）使用混合现实导航（MR-NAV）系统。
从根据 Walch 和 Favard 分类显示肩胛盂侵蚀模式的患者中获得 20 个（20）个计算机断层扫描（CT）扫描。使用经过验证的 3 维（3D）术前规划软件对病例进行规划。然后使用 CT 数据 3D 打印每个肩胛盂的 3 个重复塑料模型，以评估 3 种导针插入技术。第一种技术采用传统软件规划结合徒手导针插入。第二种方法使用术前规划的 PSI 导板，第三种方法使用 MR-NAV 系统，该系统在导针插入过程中提供实时全息引导。一旦所有导针都插入到模型中，就使用独立的光学跟踪系统和定制的数字化设备来量化每个导针相对于肩胛盂的位置和方向。本研究的结果包括导针倾斜、版本和相对于术前计划的进入点的绝对平均误差。还评估了绝对总全局误差，这被定义为相对于术前计划的导针方向和位置误差的总和。
MR-NAV 和 PSI 之间在倾斜误差（2°±1°与 2°±1°；P=0.056）、版本误差（1°±1°与 1°±1°；P>0.99）和总全局误差（5±1 [mm+deg] 与 5±1 [mm+deg]，P>0.99）方面均无统计学差异。徒手技术在倾斜（5°±3°，P≤0.017）、版本（4°±3°，P≤0.032）和总全局误差（8±3 [mm+deg]，P<0.001）方面产生的误差明显大于 MR-NAV 和 PSI。所有导针插入方法之间在进入点误差方面无统计学差异（P≥0.058）。
这些结果表明，MR-NAV 的精度和准确性与 PSI 相当，并且优于体外肩胛盂导针插入的徒手技术。需要进一步研究来比较这些技术在术中的准确性，此外还需要评估不同经验的外科医生与 MR-NAV 系统之间的潜在学习曲线。
