Dorr Lawrence D, Malik Aamer, Dastane Manish, Wan Zhinian
The Arthritis Institute at Good Samaritan Hospital, Los Angeles, CA 90017, USA.
Clin Orthop Relat Res. 2009 Jan;467(1):119-27. doi: 10.1007/s11999-008-0598-4. Epub 2008 Nov 1.
Combined cup and stem anteversion in THA based on femoral anteversion has been suggested as a method to compensate for abnormal femoral anteversion. We investigated the combined anteversion technique using computer navigation. In 47 THAs, the surgeon first estimated the femoral broach anteversion and validated the position by computer navigation. The broach was then measured with navigation. The navigation screen was blocked while the surgeon estimated the anteversion of the broach. This provided two estimates of stem anteversion. The navigated stem anteversion was validated by postoperative CT scans. All cups were implanted using navigation alone. We determined precision (the reproducibility) and bias (how close the average test number is to the true value) of the stem position. Comparing the surgeon estimate to navigation anteversion, the precision of the surgeon was 16.8 degrees and bias was 0.2 degrees ; comparing the navigation of the stem to postoperative CT anteversion, the precision was 4.8 degrees and bias was 0.2 degrees , meaning navigation is accurate. Combined anteversion by postoperative CT scan was 37.6 degrees +/- 7 degrees (standard deviation) (range, 19 degrees -50 degrees ). The combined anteversion with computer navigation was within the safe zone of 25 degrees to 50 degrees for 45 of 47 (96%) hips. Femoral stem anteversion had a wide variability.
Level II, therapeutic study. See the Guidelines for Authors for a complete description of levels of evidence.
基于股骨前倾角的全髋关节置换术中联合髋臼杯和股骨柄前倾角被认为是一种补偿异常股骨前倾角的方法。我们使用计算机导航研究了联合前倾角技术。在47例全髋关节置换术中,外科医生首先估计股骨拉刀前倾角,并通过计算机导航验证其位置。然后用导航测量拉刀。在外科医生估计拉刀前倾角时,导航屏幕被遮挡。这提供了两种股骨柄前倾角的估计值。通过术后CT扫描验证导航的股骨柄前倾角。所有髋臼杯均仅使用导航植入。我们确定了股骨柄位置的精度(可重复性)和偏差(平均测试值与真实值的接近程度)。将外科医生的估计值与导航前倾角进行比较,外科医生的精度为16.8度,偏差为0.2度;将股骨柄的导航值与术后CT前倾角进行比较,精度为4.8度,偏差为0.2度,这意味着导航是准确的。术后CT扫描显示联合前倾角为37.6度±7度(标准差)(范围为19度至50度)。47例髋关节中有45例(96%)采用计算机导航的联合前倾角在25度至50度的安全区内。股骨柄前倾角存在很大差异。
II级,治疗性研究。有关证据水平的完整描述,请参阅作者指南。