Accuracy of biplane x-ray imaging combined with model-based tracking for measuring in-vivo patellofemoral joint motion.
Accuracy of biplane x-ray imaging combined with model-based tracking for measuring in-vivo patellofemoral joint motion.
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DOI：
10.1186/1749-799x-3-38
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发表时间：
2008-09-04
影响因子：
2.6
通讯作者：
Zauel, Roger
中科院分区：
文献类型：
--
作者：
Bey, Michael J;Kline, Stephanie K;Zauel, Roger
背景：准确测量膝关节在体内的运动是一项具有挑战性的工作。传统的测量技术在很大程度上已经不能准确地测量动态活动期间在体内的三维运动。本研究的目的是评估一种新的基于模型的测量PF关节运动的技术的准确性。方法：在3具身体膝关节标本的股骨和髌骨内植入钽珠，然后在手动屈曲和伸展标本的同时记录动态双平面X线片图像，以评估该技术的准确性。使用基于模型的跟踪系统和经过验证的动态放射立体测量分析(RSA)技术，从双平面图像测量股骨和膝盖骨的位置。通过计算4个与临床相关的运动学参数的偏差、精度和总体动态精度，将基于模型的跟踪技术与动态RSA技术进行比较。结果：基于模型的跟踪技术的结果与RSA技术非常一致。总的动态精度显示，在活体条件下，膝关节移位误差小于0.395 mm，屈曲误差小于0.875度，倾斜误差小于0.863度，旋转误差小于0.877度。结论：这种基于模型的跟踪技术是一种无创性的方法，可以准确测量在体条件下的关节动力。这项技术在测量保守或手术治疗后PF关节活动的临床相关变化方面具有足够的准确性。
BACKGROUND: Accurately measuring in-vivo motion of the knee's patellofemoral (PF) joint is challenging. Conventional measurement techniques have largely been unable to accurately measure three-dimensional, in-vivo motion of the patella during dynamic activities. The purpose of this study was to assess the accuracy of a new model-based technique for measuring PF joint motion.METHODS: To assess the accuracy of this technique, we implanted tantalum beads into the femur and patella of three cadaveric knee specimens and then recorded dynamic biplane radiographic images while manually flexing and extending the specimen. The position of the femur and patella were measured from the biplane images using both the model-based tracking system and a validated dynamic radiostereometric analysis (RSA) technique. Model-based tracking was compared to dynamic RSA by computing measures of bias, precision, and overall dynamic accuracy of four clinically-relevant kinematic parameters (patellar shift, flexion, tilt, and rotation).RESULTS: The model-based tracking technique results were in excellent agreement with the RSA technique. Overall dynamic accuracy indicated errors of less than 0.395 mm for patellar shift, 0.875 degrees for flexion, 0.863 degrees for tilt, and 0.877 degrees for rotation.CONCLUSION: This model-based tracking technique is a non-invasive method for accurately measuring dynamic PF joint motion under in-vivo conditions. The technique is sufficiently accurate in measuring clinically relevant changes in PF joint motion following conservative or surgical treatment.