Papers by Keyword: Orthopedic Implants

Abstract: Background: Knee joint replacement surgery is a widely used procedure for managing severe knee osteoarthritis, rheumatoid arthritis, and traumatic arthritis. The selection of implant materials plays a crucial role in the long-term success of the procedure, influencing biomechanical stability, biocompatibility, and wear resistance. Polyether ether ketone (PEEK), a high-performance thermoplastic polymer, has recently gained attention as a potential alternative to conventional metal and polymer implants due to its closer elastic modulus to human bone, excellent biocompatibility, and radiolucency. However, the intrinsic bio-inertness and wear resistance limitations of PEEK have raised concerns regarding its early osseointegration and long-term durability. Methods: To overcome these challenges, researchers have explored various modifications, including bioactive coatings, composite reinforcement, and porous structuring, to enhance it clinical performance. This review evaluates the current applications of PEEK in knee surgery, comparing its properties with commonly used materials such as ultra-high-molecular-weight polyethylene (UHMWPE), cobalt-chromium (CoCr), and titanium. Results: We analyze its role in procedures such as high tibial osteotomy (HTO) and anterior cruciate ligament reconstruction (ACLR). While PEEK demonstrates promising mechanical and biological advantages, further studies on long-term performance, wear behavior, and improved osseointegration techniques are essential to determine its suitability as a standard implant material in knee surgery. Conclusions: PEEK has the potential to serve as an alternative implant material for knee joint replacement due to its biomechanical compatibility and favorable biological properties. However, addressing its bio-inertness and wear resistance limitations through material modifications remains a key area for future research.

Abstract: This paper explores the application of Abrasive Flow Machining (AFM) as an innovative technique to enhance the finishing process of fracture plate implants. The study aims to deepen the understanding of AFM machining dynamics, optimize process parameters, and assess the effectiveness of AFM through advanced modeling and simulation. The major contributions include detailed simulation frameworks and validation through practical applications on SS316L implants, highlighting AFM’s effectiveness in achieving high-precision finishes essential for biomedical applications.

Abstract: This work employed biocompatible and antibacterial materials to coat a commercial pure titanium (Cp-Ti) substrate for orthopedic implants applications. Three sorts of coatings were utilized using the electrophoretic deposition (EPD) technique: collagen, yttria-partially stabilized zirconia (YPSZ), and a composite of collagen/YPSZ (denoted as CZ). Surface microstructure before and after coating was examined using scanning electron microscopy (SEM). Results presented that homogeneous and uniform coating layers were successfully deposited on all samples’ surface. A relatively low pores density was observed in the surface microstructure of composite-coated sample (CZ). The chemical composition of coatings was evaluated via energy-dispersive X-ray spectroscopy (EDX), confirming that all spectra matched those of standard materials, with no signs of contaminations. Adhesion strength of coatings was evaluated using a tape test. CZ-coated sample exhibited the smallest removal area at 11.81%, demonstrating superior adhesion strength. Wettability tests were conducted on the Cp-Ti substrate before and after coating. The results showed that the application of the collagen/YPSZ composite coatings significantly enhanced surface wettability by diminishing the contact angle, making the samples surface more hydrophilic. Post-deposition antibacterial activity was estimated against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) pathogenic bacteria. All coated samples demonstrated improved antibacterial performance compared to the uncoated Cp-Ti, with the CZ-coated sample exhibiting the largest inhibition zone of 32 mm and 37 mm against both E. coli and S.aureus bacteria respectively.

Abstract: During the last decades, biomaterials have been deeply studied to perform and improve coatings for biomedical devices. Metallic materials, especially in the orthopedic field, represent the most common material used for different type of devices thanks to their good mechanical properties. Nevertheless, low/medium resistance to corrosion and low osteointegration ability characterizes these materials. To overcome these problems, the use of biocoatings on metals substrate is largely diffused. In fact, biocoatings have a key role to confer biocompatibility properties, to inhibit corrosion and thus improve the lifetime of implanted devices. In this work, the attention was focused on Hydroxyapatite-Chitosan (HA/CS) and Hydroxyapatite-Polyvinylacetate (HA/PVAc) composites, that have been studied as biocoatings for 304 SS based devices. Hydroxyapatite was selected for its osteoconductivity thanks to its chemical structure similar to bones. Furthermore, Chitosan and Polyvinylacetate are largely used yet in medical field (e.g. antibacterial agent or drug deliver) and in this work were used to create a synergic interaction with hydroxyapatite to increase the strength and bioactivity of coating. Biocotings were obtained by galvanic deposition process that does not require an external power supply. It is a spontaneous electrochemical deposition in which materials with different standard electrochemical potential were short-circuited and immersed in an electrolytic solution. Electrons supply for the cathodic reaction in the noblest material comes from oxidation of the less noble material. SEM, EDS, XRD and RAMAN were performed for chemical-physics characterization of biocoatings. Polarization and impedance measurements have been carried out to evaluate corrosion behavior. Besides, in-vitro cytotoxicity assays have been done for the biological features.