Michel Adrien, Bosc Romain, Meningaud Jean-Paul, Hernigou Philippe, Haiat Guillaume
CNRS, Laboratoire de Modélisation et de Simulation Multi-Echelle, Créteil, France.
INSERM U955, IMRB Université Paris-Est, Créteil, France.
PLoS One. 2016 Nov 28;11(11):e0166778. doi: 10.1371/journal.pone.0166778. eCollection 2016.
The primary stability of the acetabular cup (AC) implant is an important determinant for the long term success of cementless hip surgery. However, it remains difficult to assess the AC implant stability due to the complex nature of the bone-implant interface. A compromise should be found when inserting the AC implant in order to obtain a sufficient implant stability without risking bone fracture. The aim of this study is to evaluate the potential of impact signals analyses to assess the primary stability of AC implants inserted in cadaveric specimens.
AC implants with various sizes were inserted in 12 cadaveric hips following the same protocol as the one employed in the clinic, leading to 86 different configurations. A hammer instrumented with a piezoelectric force sensor was then used to measure the variation of the force as a function of time produced during the impact between the hammer and the ancillary. Then, an indicator I was determined for each impact based on the impact momentum. For each configuration, twelve impacts were realized with the hammer, the value of the maximum amplitude being comprised between 2500 and 4500 N, which allows to determine an averaged value IM of the indicator for each configuration. The pull-out force F was measured using a tangential pull-out biomechanical test.
A significant correlation (R2 = 0.69) was found between IM and F when pooling all data, which indicates that information related to the AC implant biomechanical stability can be retrieved from the analysis of impact signals obtained in cadavers.
These results open new paths in the development of a medical device that could be used in the future in the operative room to help orthopedic surgeons adapt the surgical protocol in a patient specific manner.
髋臼杯（AC）植入物的初始稳定性是无骨水泥髋关节手术长期成功的重要决定因素。然而，由于骨-植入物界面的复杂性，评估AC植入物的稳定性仍然很困难。在插入AC植入物时应找到一个折衷方案，以获得足够的植入物稳定性而不冒骨折风险。本研究的目的是评估冲击信号分析在评估尸体标本中插入的AC植入物初始稳定性方面的潜力。
按照与临床相同的方案，将各种尺寸的AC植入物插入12具尸体髋关节中，产生86种不同的配置。然后使用配备压电式力传感器的锤子来测量锤子与附件之间冲击过程中力随时间的变化。然后，根据冲击动量为每次冲击确定一个指标I。对于每种配置，用锤子进行12次冲击，最大振幅值在2500至4500N之间，这使得可以为每种配置确定指标的平均值IM。使用切向拔出生物力学试验测量拔出力F。
汇总所有数据时，发现IM与F之间存在显著相关性（R2 = 0.69），这表明可以从尸体中获得的冲击信号分析中检索与AC植入物生物力学稳定性相关的信息。
这些结果为一种医疗设备的开发开辟了新途径，该设备未来可在手术室中使用，以帮助骨科医生以患者特定的方式调整手术方案。
