Department of Orthopaedic Surgery, Hospital for Special Surgery, New York, NY.
J Arthroplasty. 2019 Apr;34(4):693-699. doi: 10.1016/j.arth.2018.12.003. Epub 2018 Dec 8.
Obesity is a risk factor for acetabular component malposition when total hip arthroplasty is performed with manual techniques. The utility of imageless navigation in obese patients remains unknown. This study compared the accuracy and precision of imageless navigation for component orientation between obese and nonobese patients.
A total of 459 total hip arthroplasties performed for osteoarthritis using imageless navigation were reviewed from a single surgeon's institutional review board-approved database. Einzel-Bild-Roentgen Analyse determined component orientation on 6-week postoperative anteroposterior radiographs. Mean orientation error (accuracy) and precision were compared between obese (body mass index ≥ 30 kg/m) and nonobese patients. Regression analysis evaluated the influence of obesity on component position.
The difference in mean inclination and anteversion between obese and nonobese groups was 1.1° (43.0° ± 3.5°; range, 35.8°-57.8° vs 41.9° ± 4.4°; range, 33.0°-57.1° and 24.9° ± 6.3°; range, 14.2°-44.3° vs 23.8° ± 6.6°; range, 7.0°-38.6°, respectively). Inclination precision was better for nonobese patients. No difference in inclination accuracy or anteversion accuracy or precision was detected between groups. And 83% of components were placed within the target range. There was no relationship between obesity (dichotomized) and component placement outside the target ranges for inclination, anteversion, or both. As a continuous variable, increased body mass index correlated with higher odds of inclination outside the target zone (odds ratio, 1.06; P = .001).
Using imageless navigation, inclination orientation was less precise for obese patients, but the observed difference is likely not clinically relevant. Accurate superficial registration of landmarks in obese patients is achievable, and the use of imageless navigation similarly improves acetabular component positioning in obese and nonobese patients.
Therapeutic Level IV.
在使用手动技术进行全髋关节置换术时，肥胖是髋臼部件位置不当的一个危险因素。无图像导航在肥胖患者中的应用效果尚不清楚。本研究比较了肥胖患者和非肥胖患者使用无图像导航时组件方向的准确性和精度。
从一位外科医生机构审查委员会批准的数据库中回顾了 459 例使用无图像导航的全髋关节置换术。通过 Einzel-Bild-Roentgen 分析确定术后 6 周前后位 X 线片上的组件方向。比较肥胖（体重指数≥30kg/m）和非肥胖患者的平均方位误差（准确性）和精度。回归分析评估了肥胖对组件位置的影响。
肥胖组和非肥胖组之间的平均倾斜度和前倾角差异为 1.1°（43.0°±3.5°；范围，35.8°-57.8° vs 41.9°±4.4°；范围，33.0°-57.1°和 24.9°±6.3°；范围，14.2°-44.3° vs 23.8°±6.6°；范围，7.0°-38.6°）。非肥胖患者的倾斜度精度更好。两组间倾斜度准确性、前倾角准确性或精度无差异。83%的组件位于目标范围内。肥胖（二分法）与目标范围内的倾斜度、前倾角或两者均不在目标范围内之间无相关性。作为一个连续变量，体重指数增加与倾斜度超出目标范围的几率增加相关（比值比，1.06；P=0.001）。
使用无图像导航时，肥胖患者的倾斜方向精度较低，但观察到的差异可能没有临床意义。在肥胖患者中，准确地进行表面标志的浅层注册是可行的，并且无图像导航的使用同样可以改善肥胖患者和非肥胖患者的髋臼部件定位。
治疗性 IV 级。
