Stem subsidence of polished and rough double-taper stems
Stem subsidence of polished and rough double-taper stems
复制标题
抛光和粗糙双锥度阀杆的阀杆下沉
作者：
A. Kaneuji;Kengo Yamada;K. Hirosaki;M. Takano;Tadami Matsumoto
背景和目的许多临床报告表明，抛光股骨柄比相同几何形状的粗糙股骨柄显示出更好的临床结果。然而，在骨水泥-骨界面处，不同表面处理对骨水泥的机械影响仍然未知。我们比较了体外骨水泥髋关节置换术模型的机械效应。方法将两种规格的双锥度抛光股骨柄和磨砂抛光股骨柄（粗糙股骨柄）固定在复合股骨上。对股骨柄施加1 Hz动态载荷，进行100万次循环。在每16小时的负载后设置8小时的空载期。测量股骨柄在骨水泥内的下沉、骨水泥-骨界面处的压缩力和水平骨水泥蠕变。结果与粗糙股骨柄相比，抛光股骨柄的股骨柄下沉、压缩力和骨水泥蠕变最大分别为4、12和7倍。对于抛光股骨柄，股骨柄下沉与压缩力之间存在强正相关性。相反，粗糙股骨柄的股骨柄下沉和压缩力之间存在很强的负相关性。对于抛光股骨柄，骨水泥上的压缩力与骨水泥蠕变之间也存在统计学显著相关性，但对于粗糙股骨柄，未发现显著相关性。解释这是第一个证据表明，不同的股骨柄表面处理对骨水泥-骨界面的骨水泥具有不同的机械效应。抛光股骨柄中的股骨柄下沉导致骨水泥上的压缩力和骨水泥蠕变。抛光锥形股骨柄在骨水泥-骨界面处对骨水泥的机械作用可能有助于其良好的长期固定和出色的临床结局。
Background and purpose Many clinical reports have indicated that polished hip stems show better clinical results than rough stems of the same geometry. It is still unknown, however, what the mechanical effects are of different surface finishes on the cement at the cement-bone interface. We compared mechanical effects in an in vitro cemented hip arthroplasty model. Methods Two sizes of double-taper polished stems and matt-processed polished stems (rough stems) were fixed into composite femurs. A 1-Hz dynamic load was applied to the stems for 1 million cycles. An 8-h no-load period was set after every 16 h of load. Stem subsidence within the cement, and compressive force and horizontal cement creep at the cement-bone interface, were measured. Results Compared to rough stems, stem subsidence, compressive force and cement creep for polished stems were a maximum of 4, 12, and 7-fold greater, respectively. There was a strong positive correlation between stem subsidence and compressive force for polished stems. In contrast, a strong negative correlation was found between stem subsidence and compressive force for rough stems. There was also a statistically significant relationship between compressive force on the cement and cement creep for the polished stems, but no significant relationship was found for rough stems. Interpretation This is the first evidence that different surface finishes of stems can have different mechanical effects on the cement at the cement-bone interface. Stem subsidence in polished stems resulted in compressive force on the cement and cement creep. The mechanical effects that polished taper stems impart on cement at the cement-bone interface probably contribute to their good long-term fixation and excellent clinical outcome.