Orthopedic Devices Research Articles

The Influence of Social Media in Orthopaedics

Social media's presence has extended to almost every industry in the world. In orthopaedics, this lends benefits to practitioners, allowing them to interact with patients, build their practice, recruit research subjects, advertise residency programs, and disperse research findings. It also allows advantages to patients, allowing them to learn about their conditions and potential treatments as many patients use social media to get health information. However, patients can also be heavily influenced by what they read online. Much of this information is not vetted by governing bodies such as the Food and Drug Administration (FDA) and Centers for Disease Control and Prevention (CDC), organizational bodies such as the American Academy of Orthopaedic Surgeons (AAOS), or the social media companies themselves. Manufacturers have started to exploit this lack of oversight by marketing products to patients with false claims that do not have rigorous clinical data behind them, creating the potential for harm. Patients are not well equipped to understand what is appropriate for the specifics of their conditions but are convinced by these powerful marketing techniques. They then come to appointments requesting treatments that are not indicated for their conditions. This strains the patient-physician relationship and can cause worse patient outcomes. Products are marketed in many fields of medicine, and orthopaedic device companies are increasingly targeting patients. This review, therefore, explores the potential benefits and drawbacks of social media in medicine in general and orthopaedics specifically and possible solutions to these issues. Namely, the introduction of some form of filtering from the FDA, CDC, other orthopaedic governing bodies, or social media platforms.

Biofilm Formation, Antibiotic Resistance, and Infection (BARI): The Triangle of Death.

Fracture-related infection (FRI) is a devastating event, directly affecting fracture healing, impairing patient function, prolonging treatment, and increasing healthcare costs. Time plays a decisive role in prognosis, as biofilm maturation leads to the development of antibiotic resistance, potentially contributing to infection chronicity and increasing morbidity and mortality. Research exploring the association between biofilm maturation and antibiotic resistance in orthopaedics primarily addresses aspects related to quality of life and physical function; however, little exists on life-threatening conditions and mortality. Understanding the intrinsic relationship between biofilm maturation, bacterial resistance, and mortality is critical in all fields of medicine. In the herein narrative review, we summarize recent evidence regarding biofilm formation, antibiotic resistance, and infection chronicity (BARI), the three basic components of the "triangle of death" of FRI, and its implications. Preoperative, perioperative, and postoperative prevention strategies to avoid the "triangle of death" of FRI are presented and discussed. Additionally, the importance of the orthopaedic trauma surgeon in understanding new tools to combat infections related to orthopaedic devices is highlighted.

Clinical evolution of patients with infection associated with orthopedic devices in treatment with continuous negative pressure

To describe the use of negative pressure therapy with (TPNi) and without instillation (TPNs) as adjuvant treatment in the management of orthopedic device-associated infections (IADO). Analytic observational study of records of patients with IADO managed with TPNi and TPNs with 0.9% saline solution, in patients > 18 years, operated on in 2018-2021. Clinical characteristics of infection, infectious agent as well as sociodemographic variables were evaluated. TPN was performed with the V.A.C. VERAFLO™ system. Analysis with χ2, Fisher and t-Student. Statistically accepted value p < 0.05. Sample 40 patients. 75% male. Fractures 42.5% exposed and 57.5% closed. 92.5% applied prophylactic antibiotic (30-120 min). 35% plate implants, 12.5% centromedullary nail, 10% knee prosthesis and 12.5% hip. 47.5% bleeding < 500 ml. 72.5% surgical time of 2-4 hours. Previous hospitalization time, TPNs 3 weeks 55.9% and 4 weeks 26.5%; TPNi, 3 weeks 50% and 4 weeks 33.3%. Conservation of the implant 73.5% TPNs and 50% TPNi (p = 0.341). Wound closure 91.2% with TPNs and 100% with TPNi (p = 1.000). The use of TPNs and TPNi were useful as adjuvant treatments in the management of IADO, in addition they allowed to preserve the implant and wound closure in a large part of the patients.

Platelet interaction and performance of antibacterial bioinspired nanostructures passivated with human plasma

The ever-increasing ageing of the world population is demanding superior orthopedic devices. Issues such as implant infection, poor osseointegration, or chronic inflammation remain problematic to the lifespan and long-term efficacy of implants. Fabrication of materials with bioinspired nanostructures is one emerging antibacterial strategy to prevent implant infection, however their interactions with blood components, and whether they retain their bactericidal properties in an environment displaying a complex protein corona, remains largely unexplored. In the present study, titanium alloy, commercially pure and plasma-sprayed titania were hydrothermally etched, passivated with human native plasma to develop a protein corona, and then incubated with either Staphylococcus aureus, Pseudomonas aeruginosa or human platelets. Surface analysis was first used to characterize the topography, chemical composition or crystallinity of each material. Fluorescence staining and SEM were performed to evaluate the nanostructure bactericidal properties, as well as to study platelet attachment and morphology. Composition of platelet supernatant was studied using ELISA and flow cytometry. Overall, our study showed that the bioinspired nanostructured surfaces displayed both impressive antibacterial properties in a complex environment, and a superior blood biocompatibility profile in terms of platelet activation (particularly for titanium alloy). Additionally, the amount of pro-inflammatory cytokines released by platelets was found to be no different to that found in native plasma (background levels) and, in some cases, presented a more pro-healing profile with an increased secretion of factors such as TGF-β, PDGF-BB or BMP-2. The nanostructured surfaces performed equally, or better, than hydroxyapatite-coated titanium which is one of the current gold standards in orthopedics. Although further in vivo studies are required to validate these results, such bioinspired nanostructured surfaces certainly show promise to be safely applied to medical device surfaces used in orthopedics and other areas.

Thirty-five Years of Reporting of Sex and Race in Clinical Studies of U.S. FDA-Authorized Orthopaedic Devices.

At the U.S. Food and Drug Administration (FDA), the mission of the Center for Devices and Radiological Health (CDRH) is to ensure that all patients and providers have timely and continued access to safe, effective, and high-quality medical devices and safe radiation-emitting products. Although the CDRH has observed enrollment differences in some clinical trials, no systematic analysis has been conducted regarding enrollment differences in baseline demographics, to our knowledge. The CDRH has summarized information on study participants and their baseline demographics in public-facing documentation for all authorized medical devices that involved orthopaedic clinical studies from 1985 to 2020. Descriptive analyses and exploratory statistical testing have been conducted to investigate the reported percentages by sex and race compared with those reported in the U.S. National Census and the American Joint Replacement Registry (AJRR), respectively. We identified 94 submissions and corresponding combined clinical trials from 261 original clinical study arms with 34,193 participants. Most of the submissions reported age and sex, while only 36 submissions (38.3%) reported racial demographics. Among the 88 trials providing enrollment by sex, the female enrollment percentage ranged from 22.2% to 88.7%, with a mean of 55.0%. In the submissions that reported racial data (38.3%), White and Black patients had a mean enrollment of 89.2% (range, 64.8% to 98.7%) and 6.2% (range, 0.4% to 20.7%), respectively. The enrollment for other minority groups ranged from 0% to 3.0%. These clinical trials have shown numerically lower female representation (55.0%) but higher White representation (89.2%) than what has been reported in the AJRR. The other racial groups have participated much less than their corresponding percentages in the U.S. population, but they are similarly represented in the AJRR. The clinical trials supporting the FDA's authorization of orthopaedic devices had a wide range of sex and racial enrollments. It appears that female enrollment mirrors the percentage of women in the U.S. population. However, despite prior efforts, some racial groups are still underrepresented. The FDA has made a commitment to advancing health equity as part of the 2022-2025 Strategic Priorities of the CDRH. We hope that the results of this study will help health-care professionals make informed clinical decisions when using medical devices.

Three-Stage Non-Surgical Treatment of Skeletal Class III Malocclusion in Adolescents—A Report of Four Cases with Long-Term Follow-Up

(1) Background: Postponing orthodontic treatment in Class III malocclusion until deterioration and growth cessation to perform orthognathic surgery does not seem to be an optimal solution for every patient. This report describes short- and long-term outcomes for nonsurgical treatment of four adolescents with severe Class III malocclusion. (2) Methods: Four patients (aged 13–15 y) with skeletal Class III (Wits appraisal below 7.5 mm) started a three-stage treatment, consisting of a six-month-long phase I and involving orthopedic treatment with an individual chin-cup. Phase II involved orthopedic treatment with a bonded Haas-type expander on acrylic splints, a face-mask, a lower fixed appliance and Class III elastics; phase III involved full fixed appliance, elastics and reuse of the individual chin-cup. Pre and posttreatment cephalograms were analyzed and superimposed. (3) Results: Improved skeletal and dental relationships and facial appearance was achieved in all patients. Wits appraisal, angles ANB, ANPg and lower face height increased; an improvement of overbite was noted. (4) Conclusions: Severe skeletal Class III in adolescents may be successfully treated with combined orthopedic/camouflage treatment with a Haas-type expander on acrylic splints, Class III elastics, fixed appliance and orthopedic devices (individual chin-cup and facemask) with a very good compliance.

Ten-year occlusion comparison of patients with cleft palate who received treatment with active or passive pre-surgical orthopedic devices

Ten-year occlusion comparison of patients with cleft palate who received treatment with active or passive pre-surgical orthopedic devices

Performance of a NLP Tool for Text Classification from Orthopaedic Operative Reports, Using Data from the Large Network of Clinical Data Warehouses of the West of France: The HACRO-HUGORTHO Project.

Electronic health data concerning implantable medical devices (IMD) opens opportunities for dynamic real-world monitoring to assess associated risks related to implanted materials. Due to population ageing and expanding demands, total hip, knee, and shoulder arthroplasties are increasing. Automating the collection and analysis of orthopedic device features could benefit physicians and public health policies enabling early issue detection, IMD monitoring and patient safety assessment. A machine learning tool using natural language processing (NLP) was developed for the automated extraction of operation information from medical reports in orthopedics. A corpus of 959 orthopaedic operative reports from 5 centres was manually annotated using the Prodigy software® with a strong inter-annotator agreement of 0.80. Data to extract concerned key clinical and procedure information (n= 9) selected by a multidisciplinary group based on the French health authority checklist. Performances parameters of the NLP model estimated an overall strong precision and recall of respectively 97.0 and 96.0 with a F1-score 96.3. Systematic monitoring of orthopedic devices could be ensured by an automated tool, leveraging clinical data warehouses. Traceability of medical devices with implantation modalities will allow detection of implant factors leading to complications. The evidence from real-world data could provide concrete and dynamic insights to surgeons and infectious disease specialists concerning implant follow-up, guiding therapeutic decision-making, and informing public health policymakers. The tool will be applied on clinical data warehouses to automate information extraction and presentation, providing feedback on mandatory information completion and contents of operative reports to support improvements, and thereafter implant research projects.

Amorphous TiO2 nano-coating on stainless steel to improve its biological response

This study delves into the potential of amorphous titanium oxide (aTiO2) nano-coating to enhance various critical aspects of non-Ti-based metallic orthopedic implants. These implants, such as medical-grade stainless steel (SS), are widely used for orthopedic devices that demand high strength and durability. The aTiO2 nano-coating, deposited via magnetron sputtering, is a unique attempt to improve the osteogenesis, the inflammatory response, and to reduce bacterial colonization on SS substrates. &#xD;The study characterized the nanocoated surfaces (SS-a TiO2) in topography, roughness, wettability, and chemical composition. Comparative samples included uncoated SS and sandblasted/acid-etched Ti substrates (Ti). The biological effects were assessed using human mesenchymal stem cells (MSCs) and primary murine macrophages. Bacterial tests were carried out with two aerobic pathogens (S. aureus and S. epidermidis) and an anaerobic bacterial consortium representing an oral dental biofilm.&#xD;Results from this study provide strong evidence of the positive effects of the aTiO2 nano-coating on SS surfaces. The coating enhanced MSC osteoblastic differentiation and exhibited a response similar to that observed on Ti surfaces. Macrophages cultured on aTiO2 nano-coating and Ti surfaces showed comparable anti-inflammatory phenotypes. Most significantly, a reduction in bacterial colonization across tested species was observed compared to uncoated SS substrates, further supporting the potential of aTiO2 nano-coating in biomedical applications.&#xD;The findings underscore the potential of magnetron-sputtering deposition of aTiO2 nano-coating on non-Ti metallic surfaces such as medical-grade SS as a viable strategy to enhance osteoinductive factors and decrease pathogenic bacterial adhesion. This could significantly improve the performance of metallic-based biomedical devices beyond titanium.

Toward Fully Automated Personalized Orthopedic Treatments: Innovations and Interdisciplinary Gaps.

Personalized orthopedic devices are increasingly favored for their potential to enhance long-term treatment success. Despite significant advancements across various disciplines, the seamless integration and full automation of personalized orthopedic treatments remain elusive. This paper identifies key interdisciplinary gaps in integrating and automating advanced technologies for personalized orthopedic treatment. It begins by outlining the standard clinical practices in orthopedic treatments and the extent of personalization achievable. The paper then explores recent innovations in artificial intelligence, biomaterials, genomic and proteomic analyses, lab-on-a-chip, medical imaging, image-based biomechanical finite element modeling, biomimicry, 3D printing and bioprinting, and implantable sensors, emphasizing their contributions to personalized treatments. Tentative strategies or solutions are proposed to address the interdisciplinary gaps by utilizing innovative technologies. The key findings highlight the need for the non-invasive quantitative assessment of bone quality, patient-specific biocompatibility, and device designs that address individual biological and mechanical conditions. This comprehensive review underscores the transformative potential of these technologies and the importance of multidisciplinary collaboration to integrate and automate them into a cohesive, intelligent system for personalized orthopedic treatments.

Improved assessment of radiofrequency electromagnetic field power deposition near orthopaedic device using a bone-inclusive ASTM phantom under 1.5T and 3T MRI

Objective. A bone-inclusive ASTM phantom is proposed to improve the assessment of radiofrequency electromagnetic field (RF-EMF) power deposition near orthopedic device under 1.5 T and 3 T magnetic resonance imaging (MRI). Approach. A phantom is created by introducing a cylindrical bone structure inside the American Society for Testing and Materials (ASTM) phantom. Four orthopaedic implant families—rod, nailing system, plate system, and hip replacement—are used in the study. RF-EMF power deposition (in terms of peak averaged specific absorption rate over 1 gram) near these implants are evaluated by placing these implants inside the standard ASTM phantom, the developed bone-inclusive ASTM phantom, and two anatomically representative human body phantoms, known as Duke and Ella. Numerical simulations are performed to calculate the RF-EMF power deposition near various orthopaedic devices within these phantoms. Main Results. For devices implanted inside or near bone tissue, the evaluation of RF-EMF power deposition using the developed bone-inclusive ASTM phantom shows better correlations to the human body phantoms than the ASTM phantom. This improvement is attributed to the portion of the devices implanted within the bone tissue. Significance. The bone-inclusive ASTM phantom has the different tissue of interests surrounding the implants compared to the ASTM phantom. This variation can lead to the different resonance frequency under RF-EMF exposure. This leads to better correlation of RF-EMF power deposition near orthopaedic implants inside human body, making the bone-inclusive ASTM phantom more suitable for evaluating RF-EMF power deposition than ASTM phantom in MRI scans.

Worrying Presence of Asymptomatic Bacterial Colonisation on Implanted Orthopedic Devices.

Background Bacterial infection after hardware implantation in orthopedic and trauma surgery is devastating, resulting in increased hospital costs and stays, multiple revision surgeries, and prolonged use of antibiotics. The present study aims to determine whether a symbiotic relationship between the human organism and bacteria in hardware implantation may be present, without clinically evident infection. Materials and methods We studied explanted devices for microbiological analysis, using the sonication technique, from patients who underwent surgical removal of musculoskeletal hardware for mechanical reasons. None of the patients included in the study had clinical or biochemical signs of infection. Results Forty-nine patients were enrolled. Cultures tested positive for bacteria in 42.8% of the 49 patients (21 of 49). In 13 patients, Gram-positive bacteria were isolated, while Gram-negative bacteria were isolated from nine patients. The most frequent bacterial species found was Pseudomonas aeruginosa, with six positive cultures (28.5%). Coagulase-negative staphylococci were isolated from ten implants (47%). Conclusion A pacific coexistence between humans and bacteria is possible following the implantation of metallic devices for trauma or orthopedic ailments. It is still unclear how strong or unstable this equilibrium is.

Prevalence of Staphylococcus aureus Infections in the Implantation of Orthopedic Devices in a Third-Level Hospital: An Observational Cohort Study.

Using orthopedic devices or prosthetic joints to treat various conditions is expected in a Traumatology and Orthopedics Unit. Recently, the materials used to build these different devices have evolved; however, pathogens can still infect these materials. Additionally, the immune system has limitations when defending against these pathogens, which results in bacterial infections like Staphylococcus aureus, Methicillin-susceptible Staphylococcus aureus (MSSA) and Methicillin-resistant Staphylococcus aureus (MRSA). A total of 276 patients who attended the Traumatology and Orthopedics Unit of our hospital from 1 June 2018 to 1 June 2019, were included in the present study. Our study analyzed the incidence of S. aureus and other bacterial pathogens in the surgical sites of patients with orthopedic implants, as well as the most used types of implants and implant materials. The specimens obtained from the surgical sites of the patients were cultured in anaerobic and aerobic media for subsequent identification using their phenotypic characteristics. Subsequently, antibiotic susceptibility tests were performed to establish the appropriate treatment. The primary pathogens identified were Staphylococcus aureus (26.4%), followed by Escherichia coli (21.0%) and Staphylococcus epidermidis (15.8%). The most commonly used implants were plates (41.7%), followed by endomedullary nails (20%), Kirschner wires (14.1%), and fixators (10.1%). As for the anatomical regions of the implants, the most frequent sites were the legs, followed by the thighs, wrists, and ankles. The pathogens were more susceptible to ciprofloxacin (95%), clindamycin (89%), and cefotaxime (86%). S. aureus is the primary infectious agent in our hospital, with an incidence of 26.4% after the placement of orthopedic implants. Although its incidence was lower compared to other tertiary hospitals, it is necessary to improve aseptic techniques in such a way as to reduce the incidence of this pathogen further.

Understanding immune-mediated titanium allergy to in situ orthopaedic implants: a narrative review of the current literature.

Clinical recognition of potential immune-mediated allergic responses to implanted metal devices is increasing. For orthopaedic implants, while 'pure' compounds are used in specific circumstances, the majority of components are alloys - a combination of two or more distinct metals. Titanium is found commonly in many orthopaedic devices and is often championed as a 'hypoallergenic' option or inclusion. In the absence of a relevant previously published summary on the topic, this paper explores the current state-of-understanding of titanium allergy and proposes a patient management algorithm whereby such immune reactions are clinically-suggested. A structured, systematic literature review was performed following PRISMA search principles to provide a contemporary summary-of-understanding in this area and to highlight clinical and knowledge deficiencies. Thirty-five topic-related articles were identified, the majority reflecting small case series' or proof-of-concept studies. The general standard of scientific evidence available was poor. Justification for arthroplasty utilization of titanium as a 'hypoallergenic' option is largely extrapolated from non-orthopaedic domains. Both ionic and conjugated titanium particles released from implant surfaces have the potential to trigger innate immune responses and true allergy. There exists no simple, high-sensitivity, screening test for titanium allergy. Conventional skin-patch testing is unreliable due to poor dermal penetration. Given established lymphocyte and macrophage activation pathways for allergy responses, in vitro methods using both cell-types show diagnostic promise. Surgical biopsy analysis from host-implant interfaces remains the contemporary 'gold-standard', however this represents an invasive, costly and highly-specialized approach not readily available in most settings. Further research to establish reliable/accessible diagnostic methods are indicated.

Evaluation of the Mechanical and Corrosion Properties of New Ti Alloys for Orthopedic Devices

Evaluation of the Mechanical and Corrosion Properties of New Ti Alloys for Orthopedic Devices

Impact of musculoskeletal disorders in patients using orthopedic equipment on sternotomy wound healing after cardiac surgery - preliminary report.

The presence of locomotive disorders may negatively impact the outcome of cardiac surgeries. This retrospective study aimed to assess the effect of preoperative diagnosis of locomotive disorders requiring the continuous use of orthopedic devices on postoperative rehabilitation and stable sternum adhesion. The study included 122 patients who underwent cardiac surgery, with 68 patients in the study group having a musculoskeletal disorder and 54 patients in the control group without such disorders. Preoperative demographic, clinical, and laboratory data as well as postoperative rehabilitation and sternum adhesion were evaluated. The results showed that patients in the study group had lower levels of calcium (p < 0.001), vitamin D (p < 0.001), and creatine kinase (p = 0.022) prior to the surgery. In the early postoperative period, 8 patients from the study group and 4 from the control group required reoperation due to sternal instability (p = ns). In the late postoperative period, sternal instability was present in 2 patients from the study group and 3 from the control group (p = ns). The survey study revealed a significantly better (p = 0.029) evaluation of postoperative rehabilitation among the study group patients. Overall, the results indicated that a preoperative locomotive disorder has no significant impact on sternal instability in the early or late postoperative periods. However, patients with such disorders have a better understanding of the importance, purpose, and course of rehabilitation after cardiac surgery and exhibit lower levels of calcium, vitamin D, and creatinine.

Multiaxial filament winding of biopolymer microfibers with a collagen resin binder for orthobiologic medical device biomanufacturing

Multiaxial filament winding is an additive manufacturing technique used extensively in large industrial and military manufacturing yet unexplored for biomedical uses. This study adapts filament winding to biomanufacture scalable, strong, three-dimensional microfiber (3DMF) medical device implants for potential orthopedic applications. Polylactide microfiber filaments were wound through a collagen ‘resin’ bath to create organized, stable orthobiologic implants, which are sized for common ligament (e.g. anterior cruciate ligament) and tendon (e.g. rotator cuff) injuries and can be manufactured at industrial scale using a small footprint, economical, high-output benchtop system. Ethylene oxide or electron beam sterilized 3DMF samples were analyzed by scanning electron microscopy (SEM), underwent ASTM1635-based degradation testing, tensile testing, ISO 10993-based cytocompatibility, and biocompatibility testing, quantified for human platelet-rich plasma (PRP) absorption kinetics, and examined for adhesion of bioceramics and lyophilized collagen after coating. 3DMF implants had consistent fiber size and high alignment by SEM. Negligible mass and strength loss were noted over 4 months in culture. 3DMF implants initially exceeded 1000 N hydrated tensile strength and retained over 70% strength through 4 months in culture, significantly stronger than conventionally produced implants made by fused fiber deposition 3D printing. 3DMF implants absorbed over 3x their weight in PRP within 5 min, were cytocompatible and biocompatible in vivo in rabbits, and could readily bind tricalcium phosphate and calcium carbonate coatings discretely on implant ends for further orthobiologic material functionalization. The additive manufacturing process further enabled engineering implants with suture-shuttling passages for facile arthroscopic surgical delivery. This accessible, facile, economical, and rapid microfiber manufacturing platform presents a new method to engineer high-strength, flexible, low-cost, bio-based implants for orthopedic and extended medical device applications.

Opinion: What are the barriers to innovation in medicine?

Opinion: What are the barriers to innovation in medicine? Thomas J. Webster, PhD provides a firsthand account of the obstacles hindering innovation in medicine, covering publishing, conferences, politics, funding, universities, and industry. Innovation is hard. Such a simple word, but so many obstacles exist to innovate and, more importantly, to turn your innovation into a medical product that actually improves human health for ultimate technology validation. As I look back at my almost 25-year career innovating in medicine, I find myself continuously reflecting on how I was able to develop innovative solutions for improving medicine despite constant obstacles. One particular innovation that I am extremely proud of involves my efforts to integrate nanotechnology into orthopedic implants. How did my team and I develop nanotextured orthopedic devices now in over 30,000 patients in which zero implants have failed to date (no infection, no chronic inflammation, and no implant loosening) when the industry average shows orthopedic implant failure rates over 10%, increasing daily (Figure 1)?(1, 2)

A 3D-printed, dynamic, patient-specific knee simulator

Purpose3D-printed devices proved their efficacy across different clinical applications, helping personalize medical treatments. This paper aims to present the procedure for the design and production of patient-specific dynamic simulators of the human knee. The scope of these simulators is to improve surgical outcomes, investigate the motion and load response of the human knee and standardize in-vitro experiments for testing orthopedic devices through a personalized physical representation of the patient’s joint.Design/methodology/approachThis paper tested the approach on three volunteers. For each, a patient-specific mathematical joint model was defined from an magnetic resonance imaging (MRI) of the knee. The model guided the CAD design of the simulators, which was then realized through stereolithography printing. Manufacturing accuracy was tested by quantifying the differences between 3D-printed and CAD geometry. To assess the simulator functionality, its motion was measured through a stereophotogrammetric system and compared with the natural tibio-femoral motion of the volunteers, measured as a sequence of static MRI.FindingsThe 3D-printing accuracy was very high, with average differences between ideal and printed parts below ± 0.1 mm. However, the assembly of different 3D-printed parts resulted in a higher average error of 0.97 mm and peak values of 2.33 mm. Despite that, the rotational and translational accuracy of the simulator was about 5° and 4 mm, respectively.Originality/valueAlthough improvements in the production process are needed, the proposed simulators successfully replicated the individual articular behavior. The proposed approach is general and thus extendible to other articulations.

FLAW DEFECTION ANALYSE OF THE SURFACE OF ACRYLIC BASE PLASTICS

This study examines the possibility of assessing the quality of removable orthopedic devices by measuring the smoothness of their surfaces and detecting microscopic defects. The methodology involves comparing standard samples of the base material with samples that have been intentionally defective, using defectoscopy techniques for analysis. Initially, twenty samples of basic acrylic plastic were selected: half of them were perfectly machined to dental standards and the other half were intentionally scratched with sandpaper. These samples were then examined by macrophotography and analyzed using Image J software for quantitative image measurement. This analysis provided numerical data on the polished surface's quality, focusing on metrics such as the total number of defects, and the average size and perimeter of these defects. Statistical evaluation through the JUSP program compared the two sets of samples, highlighting significant differences between them. From the most prominent data points provided by Image J, conclusions were made regarding the surface quality of the acrylic plastic and how it is affected by specific mechanical imperfections. This method of using optical flaw detection offers a new way to clinically evaluate the quality of detachable orthopedic devices (like base plastic) in terms of their susceptibility to bacterial buildup, which could lead to inflammation in the prosthetic bed's mucosal lining. The use of flaw detection analysis allows for a general assessment of the quality of the material surface polishing, detection of surface defects in its structure that may occur during the production stage or during operation, thereby preventing areas of biofilm accumulation. Light-optical flaw detection in the experiment proved its effectiveness and makes us pay attention to the prospects of its improvement and wider implementation in clinical practice.