Progress of interference screw in the reconstruction of anterior cruciate ligament / 中华骨科杂志

ABSTRACT

The anterior cruciate ligament (ACL) injury in sports is a common knee joint injury.It is widely accepted to reconstruct ACL under arthroscopy with autologous patellar ligament or popliteal ligament fixed in tibial or femoral tunnel with interference screws.Interference screws are widely used as intra-articular fixation devices in ACL reconstruction.The ideal materials for interference screw provide rigid fixation of graft with high mechanical strength,long-lasting stiffness and the bioactivity to stimulate osteointegration and tendon-bone healing.Current interference screws are made of metals and bio-absorbable polymers.Metallic interference screws provide high mechanical strength and stiffness for tendon graft fixation,but require a second surgery for removal.Bioabsorbable interference screws made of polymers avoid second surgery for removal,but have lower mechanical strength and might cause aseprtic inflammation during its degradation as well as screw slip,tunnel enlargement and many other complications.Magnesium (Mg) has been investigated as a novel and potential biomaterials for biodegradable interference screws.Mg is essential nutrient element and has good biocompatibility.Its mechanical strength and related stiffness are much higher than that of biodegradable polymers and are close to cortical bone.Furthermore,the degradation rate of Mg in vivo could be modulated via techniques such as alloying.In previous studies,the relationship between screw design and its pull-out force has been investigated,based on which the design of interference screw is optimized.The mechanical properties (the ultimate load to failure and the related stiffness) of interference screws proved to be higher than that of bioabsorbable interference screws sharing the same design both in vitro and in vivo.Furthermore,Mg performs good biocompatibility without severe intra-articular inflammatory reactions,as well as unique bioactivities to promote osteointegration,mineral deposition and the regeneration of fibrocartilaginous entheses.The present study reviews the researches of Mg interference screws both in vitro and in vivo,gives reference for further research and has great importance for the application of Mg interference screws in ACL reconstruction.