Department of Orthopaedic and Trauma Surgery, Saint Antoine Hospital, 184 rue du Faubourg Saint Antoine, 75571 Paris cedex 12, France.
Int Orthop. 2012 Nov;36(11):2205-9. doi: 10.1007/s00264-012-1650-2. Epub 2012 Sep 5.
Malposition of the acetabular cup is the most common cause of total hip arthroplasty (THA) dislocation. The position of a total hip implant is usually analysed on computed tomography (CT) scan. We aim to prove it is possible to measure, with good accuracy, the position of an acetabular cup using the low-dose irradiation (EOS) imaging.
We implanted an acetabular cup in a pelvic dry bone and measured cup anteversion and inclination with scanography. We performed 14 series of EOS acquisitions with different inclination, rotation and pelvic tilt, which were analysed by five observers. Two observers repeated angle measurements. We then calculated measurement inter- and intrareproducibility and accuracy.
Using a confidence interval (CI) of 95 %, inter- and intra-observer reproducibility were ±1.6, and ±1.4°, respectively, for cup inclination; accuracy in comparison with CT was ±2.6°. Using a 95 % CI, inter- and intra-observer reproducibility for cup anteversion were ±2.5° and ±2.3°, respectively. Measurement accuracy compared with CT was ±3.9°.
EOS imaging system is superior to standard radiography in terms of measuring acetabular anteversion and inclination.
髋臼杯位置不良是全髋关节置换术（THA）脱位的最常见原因。全髋关节植入物的位置通常在计算机断层扫描（CT）扫描上进行分析。我们旨在证明使用低剂量辐射（EOS）成像测量髋臼杯位置是可行的，并且具有良好的准确性。
我们将髋臼杯植入骨盆干骨中，并使用扫描法测量杯前倾角和倾斜度。我们进行了 14 组不同倾斜度、旋转和骨盆倾斜的 EOS 采集，由 5 名观察者进行分析。两名观察者重复了角度测量。然后，我们计算了测量的重复性和准确性。
使用 95%置信区间（CI），杯倾斜的观察者间和观察者内的可重复性分别为±1.6°和±1.4°；与 CT 相比，准确性为±2.6°。使用 95%CI，杯前倾角的观察者间和观察者内的可重复性分别为±2.5°和±2.3°。与 CT 相比，测量的准确性为±3.9°。
EOS 成像系统在测量髋臼前倾角和倾斜度方面优于标准射线照相术。
