Kaneuji Ayumi, Chen Mingliang, Takahashi Eiji, Takano Noriyuki, Fukui Makoto, Soma Daisuke, Tachi Yoshiyuki, Orita Yugo, Ichiseki Toru, Kawahara Norio
Department of Orthopaedic Surgery, Kanazawa Medical University, Kahoku-gun 920-0293, Japan.
Department of Orthopaedics, Affiliated Renhe Hospital of China Three Gorges University, Yichang 443000, China.
J Funct Biomater. 2023 May 9;14(5):262. doi: 10.3390/jfb14050262.
Cemented polished tapered femoral stems (PTS) made of cobalt-chrome alloy (CoCr) are a known risk factor for periprosthetic fracture (PPF). The mechanical differences between CoCr-PTS and stainless-steel (SUS) PTS were investigated. CoCr stems having the same shape and surface roughness as the SUS Exeter stem were manufactured and dynamic loading tests were performed on three each. Stem subsidence and the compressive force at the bone-cement interface were recorded. Tantalum balls were injected into the cement, and their movement was tracked to indicate cement movement. Stem motions in the cement were greater for the CoCr stems than for the SUS stems. In addition, although we found a significant positive correlation between stem subsidence and compressive force in all stems, CoCr stems generated a compressive force over three times higher than SUS stems at the bone-cement interface with the same stem subsidence ( < 0.01). The final stem subsidence amount and final force were greater in the CoCr group ( < 0.01), and the ratio of tantalum ball vertical distance to stem subsidence was significantly smaller for CoCr than for SUS ( < 0.01). CoCr stems appear to move more easily in cement than SUS stems, which might contribute to the increased occurrence of PPF with the use of CoCr-PTS.
由钴铬合金（CoCr）制成的骨水泥型抛光锥形股骨柄（PTS）是假体周围骨折（PPF）的一个已知风险因素。研究了CoCr-PTS与不锈钢（SUS）PTS之间的力学差异。制造了形状和表面粗糙度与SUS埃克塞特柄相同的CoCr柄，并对每组三个进行了动态加载试验。记录了柄的下沉情况以及骨水泥界面处的压缩力。将钽球注入骨水泥中，并跟踪其运动以指示骨水泥的运动。CoCr柄在骨水泥中的运动比SUS柄更大。此外，尽管我们发现所有柄的柄下沉与压缩力之间存在显著的正相关，但在相同的柄下沉情况下（<0.01），CoCr柄在骨水泥界面处产生的压缩力比SUS柄高出三倍以上。CoCr组的最终柄下沉量和最终力更大（<0.01），并且CoCr的钽球垂直距离与柄下沉的比值明显小于SUS（<0.01）。CoCr柄在骨水泥中似乎比SUS柄更容易移动，这可能导致使用CoCr-PTS时PPF的发生率增加。
