Wang Wenzhe, Chen Fan, Zhang Zian, Yu Chaoqun, Liu Chang, Huang Zhenchao, Wang Qianqian, Zhang Haining
Department of Joint Surgery, The Affiliated Hospital of Qingdao University, Qingdao, 266000, Shandong, China.
J Robot Surg. 2025 Jul 21;19(1):409. doi: 10.1007/s11701-025-02594-w.
This study aims to evaluate the accuracy of prosthesis size prediction in MAKO robotic-assisted total hip arthroplasty (RATHA) and to assess the impact of discrepancies between the preoperative robotic plan and the actual sizes of femoral prostheses applied during surgery on the postoperative stem position. We conducted a retrospective analysis of preoperative planning, intraoperative records, and postoperative imaging data from patients who underwent RATHA. We predicted prosthesis sizes using both traditional 2D methods and robotic systems, comparing their accuracy. The cases were categorized into four groups based on the consistency between the robotic planned and applied femoral sizes: matched group, reduced group, enlarged group, and deviated group. The postoperative measurements of stem position were compared across these groups. The prediction accuracy of the robotic system for the acetabular cup (90.3% vs. 69.7%, P < 0.01) and femoral stem (75.7% vs. 59.5%, P < 0.01) was significantly higher than that of the traditional 2-D method. The absolute values of coronal plane angulation (CA) varied significantly among the three groups: 0.55° (0.15°-1.08°) in the enlarged group, 1.25° (0.40°-2.40°) in the matched group, and 2.55° (1.45°-3.13°) in the reduced group (P < 0.001). The safe zone ratio was higher in the enlarged (100%, P < 0.01) and matched groups (83.6%, P < 0.01) compared to the reduced group (60.7%). A larger stem was associated with a higher canal fill ratio (CFR) in planes C (P = 0.02) and D (P < 0.01). All data from the deviated group differed significantly from those of the other three groups. The robotic system provides a more accurate prediction of prosthesis size compared to traditional methods. The use of a smaller stem than planned was linked to a larger absolute CA and a smaller CFR. Conversely, applying a larger stem facilitates a more neutral stem position and improved press fitting. If the applied size is reduced by two or more compared to the postoperative plan, poor positioning of the femoral prosthesis should be suspected.
本研究旨在评估MAKO机器人辅助全髋关节置换术（RATHA）中假体尺寸预测的准确性，并评估术前机器人规划与手术中应用的股骨假体实际尺寸之间的差异对术后假体柄位置的影响。我们对接受RATHA的患者的术前规划、术中记录和术后影像数据进行了回顾性分析。我们使用传统二维方法和机器人系统预测假体尺寸，并比较它们的准确性。根据机器人规划的股骨尺寸与应用的股骨尺寸之间的一致性，将病例分为四组：匹配组、缩小组、增大组和偏差组。比较这些组之间假体柄位置的术后测量结果。机器人系统对髋臼杯（90.3%对69.7%，P<0.01）和股骨柄（75.7%对59.5%，P<0.01）的预测准确性显著高于传统二维方法。三组之间冠状面成角（CA）的绝对值差异显著：增大组为0.55°（0.15°-1.08°），匹配组为1.25°（0.40°-2.40°），缩小组为2.55°（1.45°-3.13°）（P<0.001）。增大组（100%，P<0.01）和匹配组（83.6%，P<0.01）的安全区比例高于缩小组（60.7%）。在C平面（P=0.02）和D平面（P<0.01）中，较大的假体柄与较高的髓腔填充率（CFR）相关。偏差组的所有数据与其他三组均有显著差异。与传统方法相比，机器人系统对假体尺寸的预测更准确。使用比计划更小的假体柄与更大的绝对CA和更小的CFR相关。相反，应用更大的假体柄有助于使假体柄位置更中立并改善压配。如果应用的尺寸比术后计划小两个或更多，则应怀疑股骨假体定位不佳。
