Li Bo-Yao, Shi Zhang-Zhi, Li Xiang-Min, Liu Xiao-Long, Yan Yu, Wang Lu-Ning
Beijing Advanced Innovation Center for Materials Genome Engineering, State Key Laboratory for Advanced Metals and Materials, School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing, 100083, China.
Institute of Materials Intelligent Technology, Liaoning Academy of Materials, Shenyang, 110004, China.
Bioact Mater. 2025 Sep 7;54:666-685. doi: 10.1016/j.bioactmat.2025.07.036. eCollection 2025 Dec.
Biodegradable Zn alloy interference screws are promising for anterior cruciate ligament reconstruction. However, previous studies not only predominantly focus on short-term (≤30 days) immersion, but also neglect influence of crevice corrosion in bone tunnel. This study develops a Zn-0.45Mn-0.2 Mg alloy with yield strength of 288.3 MPa, ultimate tensile strength of 325.4 MPa and elongation of 26.3 %. The alloy is fabricated into screws, inserted into polyurethane bone blocks and immersed in Hank's balanced salt solution for 180 days. The alloy degraded at a corrosion rate of 0.07 mm/y, with its yield strength and elongation eventually decreasing to 229 MPa and 4.3 %, respectively. Second phase detachment during long-term corrosion reduces alloy's surface fracture toughness ( ) and increases stress intensity ( ) at corrosion pits. This causes premature fracture of the alloy ( > ) and a larger decrease in the alloy's ductility (70 %) than that in strength (30 %). Crevice corrosion of the screws originates deep within the bone tunnel and spreads outward over time. Accumulation of Cl ions exacerbates corrosion severity in the narrow thread tops of the screws. This study provides a foundation for quasi-equivalent studies of Zn alloy implants, and highlights the necessity of developing ductility-attenuation-resistant Zn alloys.
可生物降解的锌合金干涉螺钉在重建前交叉韧带方面具有广阔前景。然而，以往的研究不仅主要集中在短期（≤30天）浸泡，而且忽略了骨隧道中缝隙腐蚀的影响。本研究开发了一种锌-0.45锰-0.2镁合金，其屈服强度为288.3兆帕，极限抗拉强度为325.4兆帕，伸长率为26.3%。将该合金制成螺钉，插入聚氨酯骨块中，并在汉克平衡盐溶液中浸泡180天。该合金以0.07毫米/年的腐蚀速率降解，其屈服强度和伸长率最终分别降至229兆帕和4.3%。长期腐蚀过程中的第二相分离降低了合金的表面断裂韧性（ ），并增加了腐蚀坑处的应力强度（ ）。这导致合金过早断裂（ ＞ ），并且合金延展性的下降幅度（70%）大于强度的下降幅度（30%）。螺钉的缝隙腐蚀起源于骨隧道深处，并随时间向外扩展。氯离子的积累加剧了螺钉窄螺纹顶部的腐蚀严重程度。本研究为准等效研究锌合金植入物提供了基础，并强调了开发抗延展性衰减锌合金的必要性。
