Joint Replacement Implants Research Articles

Topographical hard protective coating for joint replacement implants

Joint replacement surgery, essential for managing joint diseases, requires improvements in tribocorrosion performance to ensure surgical success and longevity of joint implants. Transition-metal light-element (TMLE) compound coatings, known for their high hardness and chemical stability, have been extensively researched and applied for surface protection of joint implants. However, these coatings typically lack a lubrication phase, leading to high friction coefficients and severe corrosion wear, which makes long-term effective protection challenging. A promising approach is to utilize the natural lubricating proteins present in body fluids, which are continuously available and can thus address long-term service issues of TMLE coatings. In this work, we utilized micro-arc oxidation (MAO) technology to develop an underlying morphology, then conformally deposited a TiB2 layer, resulting in a cratered dual-layer TiB2/MAO coating. This unique cratered dual-layer structure not only preserves the high hardness and wear resistance of TiB2 but also aims to (1) absorb wear particles to prevent abrasive wear and (2) increase surface energy to optimize protein lubrication capacity. Consequently, the TiB2/MAO coating exhibits low friction coefficients and wear rates in protein-containing simulated body fluids. Furthermore, the dual-layer TiB2/MAO coating demonstrates excellent corrosion resistance and biocompatibility. This dual-layer coating design synergistically combines the superior intrinsic properties of material with unique structural construction, while also harnessing continuously available external proteins as lubricants to further optimize performance, thereby introducing an advanced strategy for developing protective coatings for implant materials.

Orthodontic and surgical management of Goldenhar's syndrome, including joint replacement, orthognathic surgery, and polyetheretherketone implants, using virtual surgical planning

Orthodontic and surgical management of Goldenhar's syndrome, including joint replacement, orthognathic surgery, and polyetheretherketone implants, using virtual surgical planning

Evolution of the first metatarsophalangeal joint replacement

Introduction The diseases of the first metatarsophalangeal (1 MTP) joint that require surgical treatment include osteoarthritis (69 %), rheumatoid arthritis (26 %), tumors, tumor-like diseases and purulent arthritis (5 %). The treatment of arthritic 1 MTP is aimed at reducing pain and improving function. Joint replacement implants are meant to support body weight, maintain the length of the first metatarsal, provide metatarsal‑sesamoid joint functioning and restore joint motion. The purpose of the work was to analyze data from foreign and domestic literature on endoprosthetics of the 1 MTP, and briefly present analytical data on the results of using various implants.Material and methods The article presents the summary of the Russian and foreign publications on 1 MTP joint replacement. The original literature search was conducted on key resources including PubMed, eLIBRARY, MedLine, Scopus. The search strategy was comprised of keywords: “replacement of the first metatarsophalangeal joint”, “surgical treatment of hallux rigidus”, “osteoarthrosis of the first metatarsophalangeal joint”, “results of endoprosthetics of the 1st metatarsophalangeal joint”, "modernization of implants of the 1st metatarsophalangeal joint". Publications brought out between 1968 and 2022 inclusive were analyzed.Results and discussion The ideal implant should restore functional range of motion, improve function, maintain joint stability, distribute the stress across joint surfaces being wear-resistant. Over the years, various materials have been used to provide simple and reliable designs. Implants have been improved and divided into groups based on material and design, limited degrees of freedom, tribological pair composition, and the amount of articular surface replacement.Conclusion New generation implants have a more durable design, anatomical shape and improved osseointegration. The advances in joint replacement have resulted in greater patient satisfaction and increased service life. The complication rate for replacement of the 1 MTP joint remains high. This indicates the need for continued research and further work to improve implants to make them more effective and easier to use.

Irradiation Behavior of Analgesic and Nonsteroidal Anti-Inflammatory Drug-Loaded UHMWPE for Joint Replacement.

Local delivery of pain medication can be a beneficial strategy to address pain management after joint replacement, as it can decrease systemic opioid usage, leading to less side and long-term effects. In this study, we used ultrahigh molecular weight polyethylene (UHMWPE), commonly employed as a bearing material for joint implants, to deliver a wide set of analgesics and the nonsteroidal anti-inflammatory drug tolfenamic acid. We blended the drugs with UHMWPE and processed the blend by compression molding and sterilization by low-dose gamma irradiation. We studied the chemical stability of the eluted drugs, drug elution, tensile properties, and wear resistance of the polymer blends before and after sterilization. The incorporation of bupivacaine hydrochloride and tolfenamic acid in UHMWPE resulted in either single- or dual-drug loaded materials that can be sterilized by gamma irradiation. These compositions were found to be promising for the development of clinically relevant drug-eluting implants for joint replacement.

Effect of a retinoic acid analogue on BMP-driven pluripotent stem cell chondrogenesis

Osteoarthritis is the most common degenerative joint condition, leading to articular cartilage (AC) degradation, chronic pain and immobility. The lack of appropriate therapies that provide tissue restoration combined with the limited lifespan of joint-replacement implants indicate the need for alternative AC regeneration strategies. Differentiation of human pluripotent stem cells (hPSCs) into AC progenitors may provide a long-term regenerative solution but is still limited due to the continued reliance upon growth factors to recapitulate developmental signalling processes. Recently, TTNPB, a small molecule activator of retinoic acid receptors (RARs), has been shown to be sufficient to guide mesodermal specification and early chondrogenesis of hPSCs. Here, we modified our previous differentiation protocol, by supplementing cells with TTNPB and administering BMP2 at specific times to enhance early development (referred to as the RAPID-E protocol). Transcriptomic analyses indicated that activation of RAR signalling significantly upregulated genes related to limb and embryonic skeletal development in the early stages of the protocol and upregulated genes related to AC development in later stages. Chondroprogenitors obtained from RAPID-E could generate cartilaginous pellets that expressed AC-related matrix proteins such as Lubricin, Aggrecan, and Collagen II, but additionally expressed Collagen X, indicative of hypertrophy. This protocol could lay the foundations for cell therapy strategies for osteoarthritis and improve the understanding of AC development in humans.

Recent Trends and Scope of Nanotechnology in Orthopaedic Surgery: A Narrative Review

Orthopaedic implants osseointegrate better using nanophase materials because they mimic the natural trabecular bone structure better. Additionally, prostheses with nanophase coatings can lessen bacterial adherence compared to prostheses with traditional surfaces. Improved osseointegration and infection prevention may be possible with nano-coated joint replacement implants. Other potential applications with strong in-vitro findings include rapidly integrating fillers for osteochondral flaws, antitumour seleniumcoated endoprostheses, along with potent targeted Drug Delivery Systems (DDSs) for infection prevention and treatment of chronic overuse injuries. It is significant to focus on the use of nanotechnology in artificial joint replacement prostheses, drug delivery utilising nanotechnology, surgical oncology of the skeleton using nanotechnology, bone cell function using nanotechnology, applications in orthopaedic surgery, and, finally, the use of nanotechnology and its potential new fields of study for human welfare. Before nanophase devices are approved for clinical use, significant progress must be made in comprehending the potential health concerns associated with their creation, implantation, and usage habits. However, they have a lot of potential and will probably be helpful to all of us in the future. Nanotechnology is a fast-advancing area, and its applications in orthopaedic surgery are continually expanding. This review article enables academics, clinicians, and other stakeholders to stay up-to-date on the most recent advancements, innovations, and achievements in the integration of nanotechnology into orthopaedic operations. The article also focuses on the challenges of applying nanotechnology in orthopaedics, such as biocompatibility issues, regulatory hurdles, and financial considerations. Simultaneously, it can discuss potential avenues for further research, collaboration, and progress in overcoming these challenges. Discussing the practical applications and clinical consequences of nanotechnology in orthopaedic surgery is crucial. The evaluation can explore on how these improvements will affect patient outcomes, surgical techniques, and overall healthcare practices.

Cells transiently expressing periostin are required for intramedullary intramembranous bone regeneration

Intramembranous bone regeneration plays an important role in fixation of intramedullary implants used in joint replacement and dental implants used in tooth replacement. Despite widespread recognition of the importance of intramembranous bone regeneration in these clinical procedures, the underlying mechanisms have not been well explored. A previous study that examined transcriptomic profiles of regenerating bone from the marrow space showed that increased periostin gene expression preceded increases in several osteogenic genes. We therefore sought to determine the role of cells transiently expressing periostin in intramedullary intramembranous bone regeneration. We used a genetic mouse model that allows tamoxifen-inducible fluorescent labeling of periostin expressing cells. These mice underwent ablation of the bone marrow cavity through surgical disruption, a well-established intramembranous bone regeneration model. We found that in intact bones, fluorescently labeled cells were largely restricted to the periosteal surface of cortical bone and were absent in bone marrow. However, following surgical disruption of the bone marrow cavity, cells transiently expressing periostin were found within the regenerating tissue of the bone marrow compartment even though the cortical bone remained intact. The source of these cells is likely heterogenous, including cells occupying the periosteal surface as well as pericytes and endothelial cells within the marrow cavity. We also found that diphtheria toxin-mediated depletion of cells transiently expressing periostin at the time of surgery impaired intramembranous bone regeneration in mice. These data suggest a critical role of periostin expressing cells in intramedullary intramembranous bone regeneration and may lead to novel therapeutic interventions to accelerate or enhance implant fixation.

Friend or foe? Inflammation and the foreign body response to orthopedic biomaterials.

The use of biomaterials and implants for joint replacement, fracture fixation, spinal stabilization and other orthopedic indications has revolutionized patient care by reliably decreasing pain and improving function. These surgical procedures always invoke an acute inflammatory reaction initially, that in most cases, readily subsides. Occasionally, chronic inflammation around the implant develops and persists; this results in unremitting pain and compromises function. The etiology of chronic inflammation may be specific, such as with infection, or be unknown. The histological hallmarks of chronic inflammation include activated macrophages, fibroblasts, T cell subsets, and other cells of the innate immune system. The presence of cells of the adaptive immune system usually indicates allergic reactions to metallic haptens. A foreign body reaction is composed of activated macrophages, giant cells, fibroblasts, and other cells often distributed in a characteristic histological arrangement; this reaction is usually due to particulate debris and other byproducts from the biomaterials used in the implant. Both chronic inflammation and the foreign body response have adverse biological effects on the integration of the implant with the surrounding tissues. Strategies to mitigate chronic inflammation and the foreign body response will enhance the initial incorporation and longevity of the implant, and thereby, improve long-term pain relief and overall function for the patient. The seminal research performed in the laboratory of Dr. James Anderson and co-workers has provided an inspirational and driving force for our laboratory's work on the interactions and crosstalk among cells of the mesenchymal, immune, and vascular lineages, and orthopedic biomaterials. Dr. Anderson's delineation of the fundamental biologic processes and mechanisms underlying acute and chronic inflammation, the foreign body response, resolution, and eventual functional integration of implants in different organ systems has provided researchers with a strategic approach to the use of biomaterials to improve health in numerous clinical scenarios.

Efficacy and Safety of Different Trapezium Implants for Trapeziometacarpal Joint Osteoarthritis: A Systematic Review and Meta-Analysis.

Background: The trapeziometacarpal joint (TMCJ) is the most common hand joint affected by osteoarthritis (OA), and trapezium implant arthroplasty is a potential treatment for recalcitrant OA. This meta-analysis aimed to investigate the efficacy and safety of various trapezium implants as an interventional option for TMCJ OA. Methods: Web of Science, PubMed, Scopus, Google Scholar, and Cochrane library databases were searched for relevant studies up to May 28, 2022. Preferred Reported Items for Systematic Review and Meta-Analysis guidelines were adhered to, and the protocol was registered in PROSPERO. The methodological quality was assessed by National Heart, Lung, and Blood Institute tools for observational studies and the Cochrane risk of bias tool. Subgroup analyses were performed on different replacement implants; the analysis was done using Open Meta-Analyst software and P values <.05 were considered statistically significant. Results: A total of 123 studies comprising 5752 patients were included. Total joint replacement (TJR) implants demonstrate greater significant improvements in visual analogue scale pain scores postoperatively. Interposition with partial trapezial resection implants were associated with highest grip strength and highest reduction in the Disabilities of the Arm, Shoulder, and Hand (DASH) score. Revision rates were highest in TJR (12.3%) and lowest in interposition with partial trapezial resection (6.2%). Conclusion: Total joint replacement and interposition with partial trapezial resection implants improve pain score, grip strength, and DASH scores more than other implant options. Future studies should focus on high-quality randomized clinical trials comparing different implants to accumulate higher quality evidence and more reliable conclusions.

Republication of "Current Concepts Review: Hallux Rigidus".

Arthritis of the first metatarsophalangeal (MTP) joint, hallux rigid, is a common and disabling source of foot pain in the adult population. Hallux rigidus is characterized by diseased cartilage and large, periarticular osteophytes that result in a stiff, painful joint. Activity modification, sensible shoes, orthotics, anti-inflammatory medications and occasional intra-articular steroid injections can be attempted to alleviate the discomfort associated with hallux rigidus. A number of surgical options exist for the treatment of recalcitrant hallux rigidus. Cheilectomy is a useful treatment for dorsal impingement pain seen in mild hallux rigidus. A new polyvinyl alcohol hemi-arthroplasty implant has shown promising early and midterm results in the treatment of advanced hallux rigidus; however, arthrodesis of the first MTP joint remains the gold standard treatment for advanced hallux rigidus because of unpredictable outcomes after early-generation joint replacement implants.

Improved visualization of the bone-implant interface and osseointegration in ex vivo acetabular cup implants using photon-counting detector CT

BackgroundSuccessful osseointegration of joint replacement implants is required for long-term implant survival. Accurate assessment of osseointegration could enable clinical discrimination of failed implants from other sources of pain avoiding unnecessary surgeries. Photon-counting detector computed tomography (PCD-CT) provides improvements in image resolution compared to conventional energy-integrating detector CT (EID-CT), possibly allowing better visualization of bone-implant-interfaces and osseointegration. The aim of this study was to assess the quality of visualization of bone-implant-interfaces and osseointegration in acetabular cup implants, using PCD-CT compared with EID-CT.MethodsTwo acetabular implants (one cemented, one uncemented) retrieved during revision surgery were scanned using PCD-CT and EID-CT at equal radiation dose. Images were reconstructed using different reconstruction kernels and iterative strengths. Delineation of the bone-implant and bone-cement-interface as an indicator of osseointegration was scored subjectively for image quality by four radiologists on a Likert scale and assessed quantitatively.ResultsDelineation of bone-implant and bone-cement-interfaces was better with PCD-CT compared with EID-CT (p ≤ 0.030). The highest ratings were given for PCD-CT at sharper kernels for the cemented cup (PCD-CT, median 5, interquartile range 4.25–5.00 versus EID-CT, 3, 2.00–3.75, p < 0.001) and the uncemented cup (5, 4.00–5.00 versus 2, 2–2, respectively, p < 0.001). The bone-implant-interface was 35–42% sharper and the bone-cement-interface was 28–43% sharper with PCD-CT compared with EID-CT, depending on the reconstruction kernel.ConclusionsPCD-CT might enable a more accurate assessment of osseointegration of orthopedic joint replacement implants.Key points• The bone-implant interface ex vivo showed superior visualization using photon-counting detector computed tomography (PCD-CT) compared to energy-integrating detector computed tomography.• Harder reconstruction kernels in PCD-CT provide sharper images with lower noise levels.• These improvements in imaging might make it possible to visualize osseointegration in vivo.

EFFICACY AND SAFETY OF DIFFERENT TRAPEZIUM IMPLANTS FOR TRAPEZIOMETACARPAL JOINT OSTEOARTHRITIS: A SYSTEMATIC REVIEW AND META-ANALYSIS

The trapeziometacarpal joint (TMCJ) is the most common hand joint affected by osteoarthritis (OA), and trapezium implant arthroplasty is a potential treatment for recalcitrant OA. This meta-analysis aimed to investigate the efficacy and safety of various trapezium implants as an interventional option for TMCJ OA. Web of Science, PubMed, Scopus, Google Scholar, and Cochrane library databases were searched for relevant studies up to May 2022. Preferred Reported Items for Systematic Review and Meta-Analysis guidelines were adhered to and registered on PROSPERO. The methodological quality was assessed by National Heart, Lung, and Blood Institute tools for observational studies and the Cochrane risk of bias tool. Subgroup analyses were performed on different replacement implants, the analysis was done via Open Meta-Analyst software and P values &lt; 0.05 were considered statistically significant.A total of 123 studies comprising 5752 patients were included. Total joint replacement (TJR) implants demonstrate greater significant improvements in visual analogue scale pain scores postoperatively. Interposition with partial trapezial resection implants was associated with the highest grip strength and highest reduction in the Disabilities of the Arm, Shoulder, and Hand score. Revision rates were highest in TJR (12.3%), and lowest in interposition with partial trapezial resection (6.2%).Total joint replacement and interposition with partial trapezial resection implants improve pain, grip strength, and DASH scores more than other implant options. Future studies should focus on high-quality randomized clinical trials comparing different implants to accumulate higher quality evidence and more reliable conclusions.

Key Challenges in Diamond Coating of Titanium Implants: Current Status and Future Prospects.

Over past years, the fabrication of Ti-based permanent implants for fracture fixation, joint replacement and bone or tooth substitution, has become a routine task. However, it has been found that some degradation phenomena occurring on the Ti surface limits the life or the efficiency of the artificial constructs. The task of avoiding such adverse effects, to prevent microbial colonization and to accelerate osteointegration, is being faced by a variety of approaches in order to adapt Ti surfaces to the needs of osseous tissues. Among the large set of biocompatible materials proposed as an interface between Ti and the hosting tissue, diamond has been proven to offer bioactive and mechanical properties able to match the specific requirements of osteoblasts. Advances in material science and implant engineering are now enabling us to produce micro- or nano-crystalline diamond coatings on a variety of differently shaped Ti constructs. The aim of this paper is to provide an overview of the research currently ongoing in the field of diamond-coated orthopedic Ti implants and to examine the evolution of the concepts that are accelerating the full transition of such technology from the laboratory to clinical applications.

Investigation and analysis of four countries’ recalls of osteosynthesis implants and joint replacement implants from 2011 to 2021

BackgroundMedical devices are used in almost all orthopedic surgical subspecialties, and the frequency of adverse events is increasing, which should not be ignored. To provide suggestions on how to avoid implant recalls from the perspective of manufacturers, medical institutions and supervisions, as well as how to respond promptly to adverse events.MethodsThe research extracted recalls of osteosynthesis implants and joint replacement implants from January 1, 2011, to June 30, 2021, in the CNMPA, FDA, HC and ATGA websites and collected the information on device name, recall time, recall class, recall manufacturer, device classification and affected areas. Moreover, the McKinsey 7S model and fishbone diagram were used to analyze recall reasons.ResultsA total of 315 cases of osteosynthesis implants and 286 cases of joint replacement implants were reported in China, the USA, Canada and Australia. The recalls number from 2016 to 2021 was more than that from 2011 to 2015 for osteosynthesis implant (p = 0.012) and joint replacement implant (p = 0.002), and both mainly focused on class II (76.19% and 78.32%). There were statistical differences in the four countries for both implants (p = 0.000), especially osteosynthesis implant between China and the USA (p = 0.000), China and Canada (p = 0.001), the USA and Australia (p = 0.002), and joint replacement implant between China and Australia (p = 0.000).ConclusionsTo avoid the recalls of such implants, manufacturers should strictly select implant materials and components, develop detailed labels and instructions, severely control the packaging process and establish the integrity of medical device data. Medical institutions should standardize procurement procedures, use qualified equipment and train medical workers. It also requires supervisions to conduct premarket safety assessments. In addition, regulators should strengthen supervision and establish reporting systems to deal with the occurrence of adverse events promptly.

A novel heat treatment of the additively manufactured Co28Cr6Mo biomedical alloy and its effects on hardness, microstructure and sliding wear behavior

Co28Cr6Mo alloy (ASTM F75 and F1537) is one of the standard biomaterials for permanent orthopedic implants, utilized especially in case of joint replacement, such as knee and ankle prostheses. At the present, innovative Additive Manufacturing (AM) technologies, such as laser-based powder bed fusion (LPBF), also known as selective laser melting (SLM), enable the production of customized medical devices with improved mechanical properties. When dealing with implants for joint replacement, wear resistance is critical and, unlike compressive and tensile properties, the knowledge on wear behavior of the LPBF Co28Cr6Mo alloy is currently limited. Furthermore, the effect of post-process heat treatment on tribological properties, that have to be customized on the peculiar microstructure induced by LPBF, needs to be assessed. In this view, the present work first focuses on a novel direct aging treatment of the LPBF Co28Cr6Mo alloy, performed in the range 600–900 °C up to 180 min, and investigates the effects on hardness and microstructural features, with the optimized heat-treated condition found in case of 850 °C for 180 min aging treatment. Then, the attention is driven to the dry sliding wear behavior of as-built and heat-treated LPBF Co28Cr6Mo alloy, considering the conventional wrought alloy as benchmark. For testing conditions closer to the in-service ones, the as-built LPBF alloy showed a wear resistance higher than the conventional wrought alloy. The optimized aging treatment significantly modified the as-built LPBF microstructure, it improved the alloy hardness and, in general, it positively affected its friction and wear behavior.

Structural optimization of patient-specific temporomandibular joint replacement implants for additive manufacturing: novel metrics for safety evaluation and biomechanical performance

Structural optimization of patient-specific temporomandibular joint replacement implants for additive manufacturing: novel metrics for safety evaluation and biomechanical performance

Management of Non-Prosthetic Peri-Implant Fracture in a Case of Broken Intramedullary Locking Nail - A Rare Case Report and Review of Literature

A non-prosthetic peri-implant fracture (NPPIF) can be defined as a fracture in a bone with an existing non-prosthetic implant such as an extramedullary plate and screws or an intramedullary nail, NPPIFs are mostly reported together with peri-prosthetic fractures (PPFs) that occur around joint replacement implants, but they represent a separate clinical entity with different conceptual and practical considerations1. Our case is a 72-year male with a broken humerus intramedullary Nail in right upper limb who was managed with implant removal and bridge plating with locking plate. The favourable outcome in our case sheds a light in a grey region of non-prosthetic peri implant fractures of upper limbs where no definite management protocol is available. Our patient had very good outcome which was noted by 0/100 on dash scores and complete pain-free range of movement elbow and shoulder. Our case stands as a manifest for NPPIFs of humerus, which can be managed with similar protocol which was used in our case.

Late Failure of a Polyethylene Unicompartmental Knee Insert -Retrieval Analysis Protocol and Results

This study reports the investigation of a degraded polyethylene insert retrieved after the catastrophic failure of a mobile bearing knee implant, occurred after a traumatic event and leading to a late revision. Understanding wear mechanisms of polyethylene components is important to improve the implants for joint replacement. This model of unicompartmental arthroplasty, due to its mobile, congruent insert and design, has the potential to attain low rates of wear, leading to an improved survival of the prosthesis over fixed-bearing knee implants. During the surgical technique, however, it is critical to avoid any source of impingement or incongruent articulation, as this are associated with increased rates of polyethylene wear and may contribute to the early necessity for revision surgery. The investigated insert presented a macroscopic fragmentation, surface and bulk defects and debris. Characterization of the retrieved polyethylene implant fragments was performed by macroscopic examination, by scanning electron microscopy and Fourier transform infrared spectroscopy. Due to a systematic retrieval analysis according to current standards, we can question that, in our case, third body wear is rarely pure bone or pure cement debris related but a combination of the two mentioned. The combination enhanced contribution of polyethylene debris in severe wear initiation and progression. Complete examination of the explants exhibiting breakage or severe wear may help in understanding pathogenic ways of failure in unicompartmental knee.

Development and Validation of a Finite Element Model of Wear in UHMWPE Liner Using Experimental Data From Hip Simulator Studies.

The wear of acetabular liner is one of the key factors determining osseointegration and long-term performance of total hip joint replacement implants. The experimental measurements of wear in total hip replacement components are time and cost-intensive. While addressing this aspect, a finite element model of a hip joint bearing consisting of zirconia-toughened alumina femoral head and ultrahigh molecular weight polyethylene liner was developed to predict the dynamic wear response of the liner. The Archard-Lancaster equation, consisting of surface contact pressure, wear rate, and sliding distance, was employed to predict the wear of the acetabular liner. The contact pressure and wear at the articulating surface were found to decrease over time. A new computational method involving three-dimensional point clouds from the finite element analyzed results were used to construct wear maps. The model was able to predict the linear wear, over 2 × 106 cycles with relative errors ranging from 9% to 36% when compared to the published results. The increasing error percentage occurring primarily from the use of a constant wear rate was reduced to a maximum of 17% by introducing a correction factor. The volumetric rate was predicted with a maximum relative error of 7% with the implementation of the correction factor. When the model was implemented to study acetabular liners of diameters ranging from 28 to 36 mm, the linear wear was seen to decrease with an increase in femoral head diameter, which is in agreement with the clinical data. This study emphasizes the need to develop more such FEA-based computational studies to reliably predict and correlate with experimentally measured temporal evolution of wear of load-bearing articulating joints.

Nickel-free high-nitrogen austenitic steel outperforms CoCrMo alloy regarding tribocorrosion in simulated inflammatory synovial fluids.

CoCrMo alloys are well-established biomaterials used for orthopedic joint replacement implants. However, such alloys have been associated with clinical problems related to wear and corrosion. A new generation of austenitic high-nitrogen steels(AHNSs) has been developed for biomedical applications. Here, we have addressed influences of hyaluronic acid, combined with inflammatory (oxidizing) conditions, on tribocorrosion of the high-nitrogen FeCrMnMoN0.9 steel (DIN/EN X13CrMnMoN18-14-3, 1.4452), and of the low carbon CoCrMo0.03 alloy (ISO 5832-12). We aimed to elucidate critical and clinically relevant conditions affecting the implant's performance in certain orthopedic applications. Tribocorrosion tests were conducted in triplicate, with discs under reciprocating sliding wear against a ceramic ball. Different lubricants were prepared from standardized bovine serum solution (ISO 14242-1), with variable additions of hyaluronic acid (HA) and hydrogen peroxide (H2 O2 ). Test conditions were: 37°C, 86,400 cycles, 37 N load (20-40 MPa after run-in phase). Volumetric wear was quantified; surfaces were evaluated by electrochemical parameters and microscopy/spectroscopy analyses (SEM/EDS). Factorial analysis of variancetests was conducted to examine the effects of HA, H2 O2 , and test material on wear- and corrosion-related dependent variables. Tribocorrosion performances of CoCrMo0.03 and FeCrMnMoN0.9 were comparable in fluids without H2 O2 . With higher H2 O2 concentrations, tribocorrosion increased for CoCrMo0.03 , while this was not the case for FeCrMnMoN0.9 . HA significantly enhanced wear of CoCrMo0.03 in the absence of H2 O2 , while it mitigated the tribocorrosive action of 3 mM H2 O2 ; HA had no impact on FeCrMnMoN0.9 . These results indicate a favorable performance of FeCrMnMoN0.9 compared to CoCrMo0.03 , and encourage further research on AHNS for certain orthopedic applications.