Advances in non-biodegradable metallic pedicular screw: From asubstrate material prospective

Pedicle screws are essential for spinal surgeries, offering stability and support for spinal fusion anddeformity correction. Titanium alloys, particularly Ti-۶Al-۴V and Ti-۶Al-۷Nb, are commonly used due to theirfavorable mechanical properties, including strength, low elastic modulus, and excellent biocompatibility. Ti-۶Al-۷Nboffers superior corrosion resistance and enhanced biocompatibility compared to Ti-۶Al-۴V, making it a preferredoption for long-term medical implants. These alloys are effective in reducing stress shielding and improving boneintegration due to their reduced stiffness, although surface treatments are often needed to improve biocompatibilityand wear resistance. ۳۱۶L stainless steel, with its superior strength and corrosion resistance, is another material used inspinal implants. However, its higher elastic modulus compared to titanium alloys can lead to stress shielding, whichmay affect long-term implant success. Despite this, it remains a cost-effective alternative to titanium alloys, especially inless critical applications. Nitinol, a nickel-titanium alloy with unique superelastic and shape memory properties, hasshown potential for spinal implants, particularly in osteoporotic bone. Its flexibility and reduced stiffness reduce stressshielding, and its ability to adapt to the bone structure helps in preventing adjacent segment disease. However, Nitinol’ssusceptibility to fretting corrosion, particularly when paired with titanium, requires careful consideration and surfacetreatments like electropolishing or DLC coatings to improve its long-term stability and biocompatibility.Overall, ongoing research and advancements in surface treatments and hybrid materials are crucial for optimizing theperformance of pedicle screws and improving long-term outcomes for patients.

کلیدواژه ها:

Pedicle screws ، pull-out force ، inflammation ، Ti alloys ، Stress shielding