Musculoskeletal Research Laboratory, Department of Orthopaedics &Traumatology, The Chinese University of Hong Kong, Hong Kong SAR, PR China.
Department of Orthopedics, Affiliated Zhongshan Hospital of Dalian University, Dalian, China.
Sci Rep. 2017 Jan 10;7:40369. doi: 10.1038/srep40369.
The incorporation of tendon graft into bone tunnel is one of the most challenging clinical issues in anterior cruciate ligament (ACL) reconstruction. As a biodegradable metal, Mg has appropriate mechanical strength and osteoinductive effects, thus may be a promising alternative to commercialized products used for graft fixation. Therefore, it was hypothesized that Mg based interference screws would promote tendon graft-bone junction healing when compared to Ti screws. Herein, we compared the effects of Mg and Ti screws on tendon graft healing in rabbits with ACL reconstruction via histological, HR-pQCT and mechanical analysis. The histological results indicated that Mg screws significantly improved the graft healing quality via promoting mineralization at the tendon graft enthesis. Besides, Mg screws significantly promoted bone formation in the peri-screw region at the early healing stage. Importantly, Mg screws exhibited excellent corrosion resistance and the degradation of Mg screws did not induce bone tunnel widening. In tensile testing, there were no significant differences in the load to failure, stress, stiffness and absorption energy between Mg and Ti groups due to the failure mode at the midsubstance. Our findings demonstrate that Mg screws can promote tendon graft healing after ACL reconstruction, implying a potential alternative to Ti screws for clinical applications.
肌腱移植物与骨隧道的整合是前交叉韧带（ACL）重建中最具挑战性的临床问题之一。作为一种可生物降解的金属，镁具有适当的机械强度和成骨作用，因此可能是一种有前途的替代商业化产品用于移植物固定的材料。因此，我们假设与钛螺钉相比，基于镁的干涉螺钉将促进肌腱移植物与骨的结合处愈合。在此，我们通过组织学、高分辨率 pQCT 和力学分析比较了镁和钛螺钉对 ACL 重建中兔肌腱移植物愈合的影响。组织学结果表明，镁螺钉通过促进肌腱移植物结合处的矿化，显著改善了移植物的愈合质量。此外，镁螺钉在早期愈合阶段显著促进了螺钉周围区域的骨形成。重要的是，镁螺钉表现出优异的耐腐蚀性，镁螺钉的降解不会引起骨隧道增宽。在拉伸试验中，由于在中体处发生了失效模式，镁和钛组之间的失效负荷、应力、刚度和吸收能量没有显著差异。我们的研究结果表明，镁螺钉可促进 ACL 重建后的肌腱移植物愈合，为临床应用提供了一种替代钛螺钉的潜在选择。
