Vengust R, Daniel M, Antolic V, Zupanc O, Iglic A, Kralj-Iglic V
Department of Orthopaedic Surgery, Medical Center, Ljubljana, Slovenia.
Arch Orthop Trauma Surg. 2001 Oct;121(9):511-6. doi: 10.1007/s004020100282.
The biomechanical state of the hip after a Salter innominate osteotomy was investigated by using the radiographic data of 38 operated and 21 contralateral nonoperated hips from our archives. The centre-edge angle of Wiberg was determined from the radiographs taken shortly after the operation. From the radiographs of the latest follow-up (7-13 years after the operation), we also determined the peak value of contact hip joint stress normalized by the body weight, and the functional angle of the weight-bearing area. A mathematical model was used. We show that the geometrical parameters aside from the centre-edge angle may considerably influence the contact hip stress distribution. We also show that the functional angle of the weight-bearing area is a more relevant parameter than the normalized peak stress if the exact magnification of the images is not known and if there is considerable variation of the image size within the sample. The development of the centre-edge angle of the operated hips and of the contralateral hips was also studied. We found that the centre-edge angle increases on average during the follow-up time in the operated hips as well as in the contralateral nonoperated hips, but the average increase is smaller in the former. It is shown that an unfavorable stress distribution is connected to the decrease of the centre-edge angle over time. Finally, we found a weak positive correlation between the centre-edge angle shortly after the operation and the functional angle of the weight-bearing area at the of the latest follow-up.
通过使用我们存档的38例接受手术的髋关节和21例对侧未手术髋关节的影像学数据，研究了Salter髋臼截骨术后髋关节的生物力学状态。Wiberg中心边缘角由术后不久拍摄的X线片确定。从最新随访（术后7 - 13年）的X线片中，我们还确定了以体重归一化的髋关节接触应力峰值以及负重区的功能角度。使用了一个数学模型。我们表明，除中心边缘角外的几何参数可能会显著影响髋关节接触应力分布。我们还表明，如果图像的确切放大倍数未知且样本内图像大小存在相当大的变化，负重区的功能角度比归一化峰值应力是更相关的参数。还研究了手术侧髋关节和对侧髋关节中心边缘角的发育情况。我们发现，在随访期间，手术侧髋关节以及对侧未手术髋关节的中心边缘角平均都有所增加，但前者的平均增加幅度较小。结果表明，随着时间推移，中心边缘角的减小与不利的应力分布有关。最后，我们发现术后不久的中心边缘角与最新随访时负重区的功能角度之间存在弱正相关。
