University of Oxford, Nuffield Department of Orthopaedics, Rheumatology and Musculoskeletal Sciences, Nuffield Orthopaedic Centre, Windmill Road, Oxford OX3 7LD, UK.
Eur J Radiol. 2012 Oct;81(10):2585-91. doi: 10.1016/j.ejrad.2011.12.018. Epub 2012 Jan 10.
Pre- and post-operative radiographs of patients undergoing joint arthroplasty are often examined for a variety of purposes including preoperative planning and patient assessment. This work examines the feasibility of using active shape models (ASM) to semi-automate measurements from post-operative radiographs for the specific case of the Oxford™ Unicompartmental Knee. Measurements of the proximal tibia and the position of the tibial tray were made using the ASM model and manually. Data were obtained by four observers and one observer took four sets of measurements to allow assessment of the inter- and intra-observer reliability, respectively. The parameters measured were the tibial tray angle, the tray overhang, the tray size, the sagittal cut position, the resection level and the tibial width. Results demonstrated improved reliability (average of 27% and 11.2% increase for intra- and inter-reliability, respectively) and equivalent accuracy (p>0.05 for compared data values) for all of the measurements using the ASM model, with the exception of the tray overhang (p=0.0001). Less time (15s) was required to take measurements using the ASM model compared with manual measurements, which was significant. These encouraging results indicate that semi-automated measurement techniques could improve the reliability of radiographic measurements.
术前和术后接受关节置换术的患者的射线照片通常出于各种目的进行检查，包括术前规划和患者评估。这项工作检查了使用主动形状模型（ASM）半自动测量术后射线照片的可行性，具体针对 Oxford™单髁膝关节。使用 ASM 模型和手动方法测量胫骨近端和胫骨托的位置。由四名观察者获得数据，一名观察者进行了四组测量，以分别评估观察者间和观察者内的可靠性。测量的参数包括胫骨托角度、托外展、托尺寸、矢状切割位置、切除水平和胫骨宽度。结果表明，除了托外展（p=0.0001）外，使用 ASM 模型的所有测量值的可靠性（分别为内和间可靠性平均提高 27%和 11.2%）和准确性（比较数据值的 p>0.05）均得到改善。与手动测量相比，使用 ASM 模型进行测量所需的时间（15 秒）更少，这具有显著意义。这些令人鼓舞的结果表明，半自动测量技术可以提高射线照相测量的可靠性。
