University of Calgary, 3280 Hospital Drive NW, Calgary, Alberta T2N 4Z6, Canada.
Bone Joint Res. 2012 Oct 1;1(10):263-71. doi: 10.1302/2046-3758.110.2000117. Print 2012 Oct.
Numerous complications following total knee replacement (TKR) relate to the patellofemoral (PF) joint, including pain and patellar maltracking, yet the options for in vivo imaging of the PF joint are limited, especially after TKR. We propose a novel sequential biplane radiological method that permits accurate tracking of the PF and tibiofemoral (TF) joints throughout the range of movement under weightbearing, and test it in knees pre- and post-arthroplasty.
A total of three knees with end-stage osteoarthritis and three knees that had undergone TKR at more than one year's follow-up were investigated. In each knee, sequential biplane radiological images were acquired from the sagittal direction (i.e. horizontal X-ray source and 10° below horizontal) for a sequence of eight flexion angles. Three-dimensional implant or bone models were matched to the biplane images to compute the six degrees of freedom of PF tracking and TF kinematics, and other clinical measures.
The mean and standard deviation for the six degrees of freedom of PF tracking and TF kinematics were computed. TF and PF kinematics were highly accurate (< 0.9 mm, < 0.6°) and repeatable.
The developed method permitted measuring of in vivo PF tracking and TF kinematics before and after TKR throughout the range of movement. This method could be a useful tool for investigating differences between cohorts of patients (e.g., with and without pain) impacting clinical decision-making regarding surgical technique, revision surgery or implant design.
全膝关节置换术（TKR）后许多并发症与髌股（PF）关节有关，包括疼痛和髌骨轨迹不良，但 PF 关节的活体成像选择有限，尤其是在 TKR 之后。我们提出了一种新的序贯双平面放射学方法，该方法允许在负重下整个运动范围内准确跟踪 PF 和胫股（TF）关节，并在关节置换术前和术后进行测试。
共研究了 3 例终末期骨关节炎膝关节和 3 例 TKR 后 1 年以上随访的膝关节。在每只膝关节中，从矢状面（即水平 X 射线源和水平以下 10°）获取连续双平面放射图像，以获得 8 个屈曲角度的序列。将三维植入物或骨骼模型与双平面图像匹配，以计算 PF 跟踪和 TF 运动学的六个自由度以及其他临床指标。
计算了 PF 跟踪和 TF 运动学的六个自由度的平均值和标准差。TF 和 PF 运动学具有高度的准确性（<0.9mm，<0.6°）和可重复性。
所开发的方法允许在 TKR 前后在整个运动范围内测量活体 PF 跟踪和 TF 运动学。该方法可以成为一种有用的工具，用于研究影响手术技术、翻修手术或植入物设计等临床决策的患者队列之间的差异（例如，有无疼痛）。
