Enoksen Cathrine H, Wik Tina S, Klaksvik Jomar, Arthursson Astvaldur J, Husby Otto S, Gjerdet Nils R
1 Department of Orthopaedic Surgery, Stavanger University Hospital, Stavanger, Norway.
2 Institute of Neuromedicine and Movement Science, Norwegian University of Technology and Science, Trondheim, Norway.
Proc Inst Mech Eng H. 2017 Dec;231(12):1195-1203. doi: 10.1177/0954411917737804. Epub 2017 Nov 2.
There are principally two fixation methods in total hip arthroplasty, cemented and uncemented. Both methods have in general good long-time survival. Studies comparing cemented and uncemented femoral stems indicate that the cemented stems perform somewhat better, at least in the elderly population. The aim of this study was to compare load transfer and the initial micromotion pattern for an uncemented and a cemented stem. A total of 12 human cadavers were tested in a hip simulator during single leg and stair climbing. Strain was measured on the proximal femur before and after implantation of the prostheses, and the values were presented as percentage of physiological strain. The micromovements between the stem and bone were measured and a total point motion was calculated. The results showed small statistically significant differences between the fixation methods, the largest difference being 8.1 percentage points. The uncemented stem had somewhat higher micromotion than the cemented stem, but less than 10 µm. Both stems thus had acceptable primary stability. The main finding of this study is the strain and micromotion pattern of a cemented and an uncemented stem of similar geometry is overall equal. There were small statistical significant differences between the two fixation methods regarding strain and micromotion levels. The differences are considered too small to be clinically relevant.
全髋关节置换术主要有两种固定方法，即骨水泥固定和非骨水泥固定。总体而言，这两种方法都具有良好的长期生存率。比较骨水泥固定和非骨水泥固定股骨柄的研究表明，骨水泥固定柄的表现略好一些，至少在老年人群中如此。本研究的目的是比较非骨水泥柄和骨水泥柄的载荷传递及初始微动模式。在髋关节模拟器中对12具人体尸体进行了单腿站立和爬楼梯测试。在植入假体前后测量股骨近端的应变，并将这些值表示为生理应变的百分比。测量柄与骨之间的微动，并计算总点运动。结果显示，两种固定方法之间存在微小的统计学显著差异，最大差异为8.1个百分点。非骨水泥柄的微动略高于骨水泥柄，但小于10微米。因此，两种柄都具有可接受的初始稳定性。本研究的主要发现是，几何形状相似的骨水泥柄和非骨水泥柄的应变和微动模式总体上是相同的。两种固定方法在应变和微动水平方面存在微小的统计学显著差异。这些差异被认为太小，不具有临床相关性。
