Service d'orthopédie, hôpital Pitié-Salpêtrière, 47-83, boulevard de Hôpital, 75013 Paris, France.
Inserm UMR S 1146, CNRS UMR 7371, laboratoire d'imagerie biomédicale, Sorbonne université, 75006 Paris, France.
Orthop Traumatol Surg Res. 2020 May;106(3):543-550. doi: 10.1016/j.otsr.2019.11.030. Epub 2020 Apr 4.
Three-dimensional planning (3DP) in total hip arthroplasty using computed tomography (CT) to analyze bone mineral density (BMD) at the stem-femur interface has a high reported accuracy and excellent mid-term results in the literature. However, 3DP does not take into account the effect of femoral rasping on BMD distribution within the rasped cavity. Characterizing the impact of femoral rasping on BMD may help avoid mechanical failures, but this data is not accurately investigated. Therefore, we set out a cadaveric study to identify if: (1) Femoral rasping modified regional BMD in areas considered critical for bone anchorage of cementless metaphyseally fixed anatomic stems. (2) In areas of bone-implant contact with an initial high BMD, does femoral rasping increase BMD?
Femoral rasping increases BMD in some zones considered critical for bone anchorage of cementless metaphyseally fixed anatomic stems within the rasped femoral cavity.
Four cadaveric femurs were selected to undergo a rasping procedure similar to surgical techniques used for metaphyseally fixed anatomic stems. Images of femurs before and after rasping were obtained with a micro-CT scanner (pixel size 35μm). BMD values before and after rasping were compared in a trabecular bone ring of 3mm thickness around the cavity created by the rasps, in a region extending 3cm above and 2cm below the middle of the lesser trochanter.
Average BMD increased significantly after rasping in 3 of the 4 femurs (13% (0.27 to 0.30) (p=0.004)), 12% (0.32 to 0.36 (p=0.034)) and 15% (0.4 to 0.46 (p=0.001)), while there was no significant variation in the last femur (0.32 to 0.32 (p>0.05)). Increases in regional BMD were significantly higher in the lateral and medial areas, as well as in the most distal femoral regions. There were significantly lower variations of BMD in regions with initially higher BMD.
Current opinion considers trabecular bone debris from femoral rasping to have an impact on final stem position and outcome. Our study has demonstrated an overall positive effect of femoral rasping on BMD in the rasped cavity. Understanding this in the context of 3DP may help avoid mechanical failures such as, suboptimal implant fit, fill, and stability as well as femoral fractures during stem implantation.
IV, Prospective in vitro study.
在全髋关节置换术中使用计算机断层扫描（CT）进行三维规划（3DP）可以分析股骨柄-骨界面的骨矿物质密度（BMD），文献报道其具有较高的准确性和良好的中期结果。然而，3DP 并未考虑股骨锉削对锉削腔内 BMD 分布的影响。描述股骨锉削对 BMD 的影响有助于避免机械故障，但目前尚未对此数据进行准确研究。因此，我们进行了一项尸体研究，以确定：（1）股骨锉削是否改变了被认为对非骨水泥皮质内固定解剖柄骨锚定至关重要的区域的局部 BMD。（2）在与初始高 BMD 有骨-植入物接触的区域，股骨锉削是否会增加 BMD？
股骨锉削会增加在锉削股骨腔内被认为对非骨水泥皮质内固定解剖柄骨锚定至关重要的一些区域的 BMD。
选择 4 个尸体股骨进行类似于用于皮质内固定解剖柄的手术技术的锉削操作。使用微 CT 扫描仪（像素大小 35μm）获得股骨锉削前后的图像。在由锉刀形成的腔周围的 3mm 厚的骨小梁骨环中，在小转子中部上方 3cm 和下方 2cm 的区域中，比较了锉削前后的 BMD 值。
在 4 个股骨中有 3 个（13%（0.27 至 0.30）（p=0.004））、12%（0.32 至 0.36（p=0.034））和 15%（0.4 至 0.46（p=0.001））的 BMD 显著增加，而最后一个股骨的 BMD 没有明显变化（0.32 至 0.32（p>0.05））。在外侧和内侧区域以及股骨的最远端区域，区域 BMD 的增加更为显著。在初始 BMD 较高的区域，BMD 的变化显著较小。
目前的观点认为股骨锉削产生的骨小梁碎屑会影响最终的柄位置和结果。我们的研究表明，股骨锉削对锉削腔内的 BMD 有整体积极影响。在 3DP 的背景下了解这一点有助于避免机械故障，例如，植入物配合、填充和稳定性不佳以及在柄植入过程中发生股骨骨折。
IV，前瞻性体外研究。
