Porous Implants Research Articles

Synthesis methods of Mg-based scaffolds and their applications in tissue engineering: A review.

Repair and regeneration of damaged tissues due to disease and accidents have become a severe challenge to tissue engineers and researchers. In recent years, biocompatible metal materials such as stainless steels, cobalt alloys, titanium alloys, tantalum alloys, nitinol, and Mg alloys have been studied for tissue engineering applications; as suitable candidates in orthopedic and dentistry implants. These materials and their alloys are used for load-bearing and physiological roles in biological applications. Due to the suitable conditions provided by a porous material, many studies have been performed on the porous implants, including Mg-based scaffolds. Mg alloy scaffolds are attractive due to some outstanding features and susceptibilities, such as providing a cell matrix for cell proliferation, migration, and regeneration, providing metabolic substances for bone tissue growth, biocompatibility, good biodegradability, elastic modulus comparable to the natural bone, etc. Accordingly, in the present study, a general classification of all the production methods of Mg-based scaffolds is provided. Strengths and weaknesses, the effect of the production approach on the final properties of scaffolds, including mechanical and biological capabilities, and the impact of alloying elements and process parameters have been reviewed, and discussed. Finally, the manufacturing methods have been compared and the upcoming challenges have been stated.

Extrusion of High-density Porous Polyethylene Implants in the Nose.

Few alloplastic implant materials have been successfully used in nasal reconstruction. The high-density porous polyethylene (HDPE) implant is the most widely accepted alloplastic material for reconstructing the nasal structure. Some authors suggest that the problems associated with using grafts and biocompatible materials are often due to errors on the part of the surgeon or the technique used. This study aims to report several cases of complications related to using HDPEs in the nose. A total of 23 patients who reacted negatively to alloplastic implants were treated. The removal of HDPE is complex due to the formation of connective tissue within it. These complications can cause permanent atrophic changes to the skin of the nose. Most of the patients presented with extrusion of their HDPE implants in the nasal columella region. All patients underwent implant removal, cleaning, disinfection, and secondary rhinoplasty. Surgeons must be able to recognize these possible complications and manage them successfully. Even today, many professionals use alloplastic grafts for reconstruction and esthetics of the nasal region. The potential for permanent damage to the skin and soft tissues, as well as complications such as infection and extrusion of the implant, makes the use of autogenous tissue preferable over alloplastic implants. Early detection and immediate treatment of complications are essential to minimize the severity of the deformity.

Efficacy of a saline wash plus vancomycin/tobramycin-doped PVA composite (PVA-VAN/TOB-P) in a mouse pouch infection model implanted with 3D-printed porous titanium cylinders.

The efficacy of saline irrigation for treatment of implant-associated infections is limited in the presence of porous metallic implants. This study evaluated the therapeutic efficacy of antibiotic doped bioceramic (vancomycin/tobramycin-doped polyvinyl alcohol composite (PVA-VAN/TOB-P)) after saline wash in a mouse infection model implanted with titanium cylinders. Air pouches created in female BalBc mice by subcutaneous injection of air. In the first of two independent studies, pouches were implanted with titanium cylinders (400, 700, and 100 µm pore sizes) and inoculated with Staphylococcus aureus (1 × 103 or 1 × 106 colony-forming units (CFU)/pouch) to establish infection and biofilm formation. Mice were killed after one week for microbiological analysis. In the second study, pouches were implanted with 400 µm titanium cylinders and inoculated with S. aureus (1 × 103 or 1 × 106 CFU/pouch). Four groups were tested: 1) no bacteria; 2) bacteria without saline wash; 3) saline wash only; and 4) saline wash plus PVA-VAN/TOB-P. After seven days, the pouches were opened and washed with saline alone, or had an additional injection of PVA-VAN/TOB-P. Mice were killed 14 days after pouch wash. The first part of the study showed that low-grade infection was more significant in 400 µm cylinders than cylinders with larger pore sizes (p < 0.05). The second part of the study showed that saline wash alone was ineffective in eradicating both low- and high-grade infections. Saline plus PVA-VAN/TOB-P eradicated the titanium cylinder-associated infections, as manifested by negative cultures of the washouts and supported by scanning electron microscopy and histology. Porous titanium cylinders were vulnerable to bacterial infection and biofilm formation that could not be treated by saline irrigation alone. Application of PVA-VAN/TOB-P directly into the surgical site alone or after saline wash represents a feasible approach for prevention and/or treatment of porous implant-related infections.

Short-Term Outcomes of High-Density Porous Polyethylene Orthoses for Chin and Gonial Angle Augmentation.

This retrospective observational study evaluated 100 patients over 18years. Data on age, sex, aesthetic complaints, surgery types, and postoperative complications were collected and analyzed using the two-proportion z-test and descriptive statistics in RStudio 4.3.3. All patients with neuropraxia underwent neurosensory evaluation. The average age was 35.92years for males and 33.71years for females, with a male predominance (76%). Aesthetic complaints were prevalent in 72% of patients (p < 0.01). Chin surgery was performed on 56% of patients, jaw angle surgery on 17%, and both on 39%. Complications included one case of suture dehiscence, three wound infections, and four transient cases of paresthesia, all resolving within 30days. Overall, patient satisfaction with outcomes was high. High-density porous polyethylene implants proved effective and safe in enhancing facial aesthetics and correcting mandibular deformities. Further research should focus on long-term outcomes to consolidate these findings. This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

A comprehensive study of LPBF parameter influence in 316L stainless steel mechanical properties, macrostructure, and printability

Additive manufacturing, particularly using Laser Powder Bed Fusion (LPBF) technologies with 316L stainless steel, has proven highly promising in biomedical engineering due to the material’s exceptional mechanical properties and biocompatibility. This study, which is a foundational step towards developing porous bone implants, focuses on assessing the influence of a broad range of parameters - spot size, scanning speed, laser power, and energy density - on the mechanical performance and structural integrity of 316L stainless steel parts across three distinct specimen geometries: fully dense parallelepipedic, fully dense cubic, and cellular (lattice) specimens. By analysing 17 different parameter sets and producing over 150 specimens, a thorough series of experimental tests were conducted, including flexural tests, compression tests, hardness tests, macroscopic evaluation of the surface of fully dense specimens, and macroscopic evaluation of the lattice structures.e in powder accumulation within the pores of cellular structures, with higher energy densities (100 J/mm3) leading to a significantly greater retention compared to lower energy densities (66 J/mm3). This underexplored phenomenon has significant implications for the selection of parameters in the fabrication of bone implants. Further research is needed to refine LPBF printing parameters and enhance the quality of porous bone implants.

Optimization Design and SLM Manufacturing of Porous Titanium Alloy Femoral Stem.

In order to solve the loosening problem caused by stress shielding of femoral stem prostheses in clinical practice, an optimization design method of a personalized porous titanium alloy femoral stem is proposed. According to the stress characteristics of the femur, the porous unit cell structures (TO-C, TO-T, TO-B) under three different loads of compression, torsion, and bending were designed by topology optimization. The mechanical properties and permeability of different structures were studied. Combined with the porous structure optimization, a personalized radial gradient porous titanium alloy femoral stem was designed and manufactured by selective laser melting (SLM) technology. The results show that the TO-B structure has the best comprehensive performance among the three topologically optimized porous types, which is suitable for the porous filling structure of the femoral stem, and the SLM-formed porous femoral stem has good quality. The feasibility of the personalized design and manufacture of porous titanium alloy implants is verified, which can provide a theoretical basis for the optimal design of implants in different parts.

Engineering of multilayered coating on additively manufactured Ti-6Al-4V porous implants to promote tribological and fatigue performances

Despite the numerous advantages of additively manufactured Ti-6Al-4V porous implants surface modified by plasma electrolyte oxidation (PEO) coatings in biomedical applications, several challenges still persist regarding their tribological and fatigue performances. To address these challenges, this study aims to engineer an innovative multilayered coating based on physical vapor deposited (PVD) Nb/NbN coatings on PEO-treaded Ti-6Al-4V porous implants. Three configurations of Nb/NbN coatings, including one, two, and three PVD layers were deposited on PEO-treated Ti-6Al-4V implants to simultaneously assess the effects of both increased coating thickness and configuration on the surface topography and mechanical performances of Ti-6Al-4V implants. Results showed that increasing the thickness and number of coatings changed the surface morphology and reduced the surface roughness. The PVD/PEO treatment demonstrated enhanced wear resistance of Ti-6Al-4V samples compared to the PEO treatment, depending on the coating conditions. Noticeably, the samples with 2 Nb/NbN layers exhibited the highest wear resistance and decreased the wear rate by 90 % compared to the Ti-6Al-4V samples. Although PEO treatment resulted in a decrease in fatigue life, the deposition of Nb/NbN coatings, especially those with 2 and 3 layers, markedly improved fatigue resistance compared to the PEO-treated samples. These modified samples attained approximately 81 % and 84 % of the fatigue life of the not-treated Ti-6Al-4V samples, respectively. Overall, the deposition of multilayered PVD Nb/NbN coatings on PEO-treated Ti-6Al-4V implants demonstrated an effective improvement in wear resistance while maintaining acceptable fatigue life under cyclic loading, making it promising for biomedical implants.

3D-printed porous titanium rods equipped with vancomycin-loaded hydrogels and polycaprolactone membranes for intelligent antibacterial drug release

Implant-related infections pose significant challenges to orthopedic surgeries due to the high risk of severe complications. The widespread use of bioactive prostheses in joint replacements, featuring roughened surfaces and tight integration with the bone marrow cavity, has facilitated bacterial proliferation and complicated treatment. Developing antibacterial coatings for orthopedic implants has been a key research focus in recent years to address this critical issue. Researchers have designed coatings using various materials and antibacterial strategies. In this study, we fabricated 3D-printed porous titanium rods, incorporated vancomycin-loaded mPEG750-b-PCL2500 gel, and coated them with a PCL layer. We then evaluated the antibacterial efficacy through both in vitro and in vivo experiments. Our coating passively inhibits bacterial biofilm formation and actively controls antibiotic release in response to bacterial growth, providing a practical solution for proactive and sustained infection control. This study utilized 3D printing technology to produce porous titanium rod implants simulating bioactive joint prostheses. The porous structure of the titanium rods was used to load a thermoresponsive gel, mPEG750-b-PCL2500 (PEG: polyethylene glycol; PCL: polycaprolactone), serving as a novel drug delivery system carrying vancomycin for controlled antibiotic release. The assembly was then covered with a PCL membrane that inhibits bacterial biofilm formation early in infection and degrades when exposed to lipase solutions, mimicking enzymatic activity during bacterial infections. This setup provides infection-responsive protection and promotes drug release. We investigated the coating’s controlled release, antibacterial capability, and biocompatibility through in vitro experiments. We established a Staphylococcus aureus infection model in rabbits, implanting titanium rods in the femoral medullary cavity. We evaluated the efficacy and safety of the composite coating in preventing implant-related infections using imaging, hematology, and pathology. In vitro experiments demonstrated that the PCL membrane stably protects encapsulated vancomycin during PBS immersion. The PCL membrane rapidly degraded at a lipase concentration of 0.2 mg/mL. The mPEG750-b-PCL2500 gel ensured stable and sustained vancomycin release, inhibiting bacterial growth. We investigated the antibacterial effect of the 3D-printed titanium material, coated with PCL and loaded with mPEG750-b-PCL2500 hydrogel, using a rabbit Staphylococcus aureus infection model. Imaging, hematology, and histopathology confirmed that our composite antibacterial coating exhibited excellent antibacterial effects and infection prevention, with good safety in trials. Our results indicate that the composite antibacterial coating effectively protects vancomycin in the hydrogel from premature release in the absence of bacterial infection. The outer PCL membrane inhibits bacterial growth and prevents biofilm formation. Upon contact with bacterial lipase, the PCL membrane rapidly degrades, releasing vancomycin for antibacterial action. The mPEG750-b-PCL2500 gel provides stable and sustained vancomycin release, prolonging its antibacterial effects. Our composite antibacterial coating demonstrates promising potential for clinical application.

Preparation and Biological Evaluation of Porous Tantalum Scaffolds Coated with Hydroxyapatite.

Orthopedic implants, such as porous scaffolds, are an effective way to repair bone defects. However, the lack of osseointegration and osteoinduction limits the achievement of an ideal therapeutic effect. This study aimed to prepare hydroxyapatite (HA) coatings for the surface of porous tantalum (Ta) scaffolds and to assess the effectively improved biological activities of the coated scaffolds. The porous Ta scaffolds were prepared by chemical vapor deposition, and then the porous Ta scaffolds were coated with HA via electrochemical deposition. The elements and phase compositions of the coatings were analyzed by energy-dispersive X-ray spectroscopy, X-ray diffraction, and X-ray photoelectron spectroscopy. The results showed that the coating covered the whole surfaces of porous Ta scaffolds with a uniform and compact distribution and did not exert any obvious effect on the porous structure. The biological activity of porous Ta scaffolds after surface modification increased and the water contact angle decreased, indicating that hydrophilicity was significantly improved. Cell live/dead staining, cytoskeletal fluorescence staining, and alkaline phosphatase immunofluorescence staining showed that the coating exhibited no cytotoxicity and notably improved cell proliferation, spreading, and osteogenic differentiation. In addition, in vivo experiments in animals have demonstrated that HA-coated porous Ta scaffolds contribute to bone formation. In conclusion, the HA coating notably improves the biological activities of the porous Ta scaffolds, achieving the goal of the present study. The HA coating presents great potential for the modification of porous Ta implants to improve their osteogenesis and osseointegration.

Structural optimization design and compression performance of porous titanium prepared by laser powder bed fusion

Porous implants composed of periodically-repeating porous units have been applied in orthopedic surgeries to replace damaged bones. An important requirement for bone implants is to find a balance between biological and mechanical properties, that is, to ensure high pore connectivity and a certain strength. In this work, center-supported and perimeter-supported porous optimization models were established by a swarm intelligence optimization algorithm, and the corresponding titanium porous samples were fabricated by laser powder bed fusion (L-PBF). The effects of cell topology and porosity on the compressive behavior of L-PBF titanium porous structures were systematically investigated by a combination of compression simulation and experiments. Compression simulation shows that the deformation failure behavior of center-supported and perimeter-supported porous structures consists of three stages: elastic deformation, plastic deformation and compression collapse, showing the characteristics of elastic-plastic porous materials. According to the compression test results, the compressive strength of center-supported and perimeter-supported structure samples are 151–188 MPa and 178–196 MPa, respectively, and the compressive stability of the perimeter-supported structure is better than that of the center-supported structure. The porosity error of center-supported structure is 1.6%–2.9%, and the porosity error of perimeter-supported structure is 3.1%–4.5%. The compressive strength of the same type of structure decreases with the increase of the porosity of the porous structure. The simulation/experimental compressive strength errors of center-supported and perimeter-supported structures are less than 6% and 5.9%, respectively. The constructed quasi-static compression model has certain guiding significance for the study of the fracture of the titanium implants under external force.

Prediction of micro-scale bone adaptation of human trabecular bone under different implanted conditions

Background and objectiveDifferent bone remodeling algorithms are used to predict bone adaptation and to understand how bones respond to the mechanical stimuli altered by implants. This paper introduces a novel micro-scale bone remodeling algorithm, which deviates from conventional methods by focusing on structure-based bone adaptation instead of density-based approaches. MethodsThe proposed model simulated cellular activities such as bone resorption, new bone formation, and maturation of newly formed bone. These activities were assumed to be triggered by mechanical stimuli. Model parameters were evaluated for the 3D geometries of trabecular bone from intact femur developed from micro computed tomography (CT) scan data. Two different hip implants, solid and porous were used, and two different bone remodeling methods were performed using the proposed and conventional methods. ResultsResults showed that micro CT scan-based finite element (FE) models accurately captured the microarchitecture and anisotropy of trabecular bone. The predicted bone resorption rate at the peri-prosthetic regions for the solid and porous implants was in the range of 17–27% and 4.5–7.3%, respectively, for a simulated period of four years. ConclusionsThe results obtained from FE analysis strongly align with clinical findings, confirming the effectiveness of the proposed algorithm. By emphasizing the structural aspect of bone adaptation, the proposed algorithm brings a fresh perspective on bone adaptation at the peri-prosthetic bone. This method can help researchers and clinicians to improve implant designs for better clinical outcomes.

Compressive properties and biocompatibility of additively manufactured lattice structures by using bioactive materials

Porous bioactive materials were widely used in orthopedic implant fields because of their excellent mechanical properties and porous spaces. However, most porous types are predominantly stacked in two-dimensional configurations, which significantly limits their mechanical property range and adversely affects the modulus matching between the porous implants and surrounding bone tissues. Hence, various lattice structures were prepared using 3D printing technology with bioactive materials, and characterized by mechanical and biological tests. Numerical simulations were conducted to analyze the effect of relative density and geometric parameters on the equivalent compressive properties of the lattice structures. The results showed that the lattice structure exhibited a broad elastic modulus range, which can be adjusted to align with the mechanical properties of human cortical and cancellous bones, thereby helping to mitigate stress shielding in orthopedic implants. The biocompatibility of the 3D-printed solid materials was assessed in vitro using a cell counting assay kit-8 (CCK-8). The results indicated that poly-ether-ether-ketone (PEEK), carbon fiber reinforced PEEK (CFR/PEEK), nylon, and titanium (Ti) alloy all exhibited good biocompatibility, with no significant differences observed among the four materials. This study further enhances the understanding of bioactive lattice structures in the biomedical field and offers new possibilities for orthopedic repair.

Influence of Porosities of 3D Printed Titanium Implants on the Tensile Properties in a Rat Tendon Repair Model.

There is a desire in orthopaedics to have soft tissue, particularly tendon, grow into metallic implants. With the introduction of three-dimensional (3D) printed porous metal implants, we hypothesized that tendons could directly attach to the implants. However, the effects of the porous metal structure on tissue growth and penetration into the pores are unknown. Using a rat model, we investigated the effect of pore size on tendon repair fixation using 3D printed titanium implants. There were three experimental groups of eight Sprague Dawley rats (n = 24) plus control (n = 3). Implants had defined pore sizes of 400µm (n = 8), 700µm (n = 8), and 1000µm (n = 8). A defect was created in the Achilles tendon and the implant positioned between cut ends and secured with suture. Specimens were harvested at twelve weeks. Half the specimens underwent mechanical testing to assess tensile load to failure. The remaining specimens were fixed and processed for hard tissue histological analysis. The average load to failure was 72.6N for controls (SD 10.04), 29.95N for 400µm (SD 17.95), 55.08N for 700µm (SD 13.47), and 63.08N for 1000µm (SD 1.87). The load to failure was generally better in the larger pore sizes. The 700µm and 1000µm specimens performed similarly, while the 400µm showed significant differences vs control (p = 0.039), vs 1000µm (p = 0.010), and approached significance vs 700µm (p = 0.066). There was increasing ingrowth as pore size increased. Histology showed fibrous tendon tissue within and around the implants, with collagen fibers organized in bundles. Tendon repair utilizing implants with 700µm and 1000µm pores exhibited similar load to failure as controls. Using a defined pore structure at the attachment points of tendons to implants may allow predictable tendon ingrowth onto/into an implant at the time of revision arthroplasty.

Unveiling the safety landscape: A comprehensive review of the toxicological profile of facial aesthetic implants and biomaterials

Exploring diverse biomaterials and implants in the ear, nose, and throat by understanding adverse effects and post-usage events. Literature was obtained from Scopus, PubMed, Google Scholar, and Web of Science. A comprehensive analysis was conducted on original research studies, case reports, and case series spanning from December 2010 to May 2022. Our analysis underscores that the effectiveness of cochlear implants (CIs) relies on factors such as biocompatibility, anti-inflammatory measures, and fibrosis reduction. Although silicone is employed in otologic applications, allergic reactions leading to CI extrusion are rare. In the context of partial ossicular replacement prostheses or total ossicular replacement prostheses, polyethylene grafts (Teflon) are utilized, and Nitinol-pistons are employed in stapedotomy, with adverse consequences encompassing graft extrusion and residual perforation. Chronic sphenoid sinusitis is linked to the use of Medpor porous polyethylene implants in sellar reconstruction during skull-based surgeries. Injectable collagen preparations in vocal cord paralysis lead to submucosal deposits and resultant dysphonia. Montgomery T-tubes are employed for subglottic stenosis but are associated with granulation tissue formation. Metallic tracheostomy tubes give rise to secondary foreign bodies, and double-lumen tracheostomy tubes are prone to biofilm formation. Despite numerous research studies, there remains a necessity for the refinement of implant designs to mitigate complications and enhance the overall quality of life for patients.

Long-term enophthalmos after complex orbital bone loss successfully treated with patient-specific porous titanium implants: A case series

IntroductionLong-term enophthalmos and diplopia resulting from orbital bone loss pose significant challenges in reconstructive surgery. This study evaluated the effectiveness of patient-specific porous titanium implants (PSIs) for addressing these conditions. Materials and methodsThis retrospective study involved 12 patients treated at Croix-Rousse Hospital, Lyon, from April 2015 to April 2022 who underwent late reconstruction via PSI for unilateral complex orbital bone loss. These implants were customized via 3D mirroring techniques on the basis of high-resolution computed tomography (CT) scans of the patients' unaffected orbits. ResultsAll 12 patients presented with significant preoperative enophthalmos, with an average displacement of 3.24 mm, which was effectively corrected postoperatively to an average of 0.17 mm (p < 0.001). Orbital volume notably improved from a preoperative average of 3.38 mL to 0.37 mL postsurgery (p < 0.001). Functional improvements were evident as both enophthalmos and diplopia resolved completely. The Lancaster test revealed an improvement in the visual field, with 83.3 % of patients achieving normal results postoperatively. DiscussionBy ensuring anatomical accuracy, patient-specific porous titanium implants, tailored from patient-specific imaging and fabricated via advanced 3D printing technology, provide a precise, effective, and reliable solution for reconstructing complex orbital defects and performing complicated revision surgeries.

Long-Term Mental Health after High-Density Polyethylene-Based Porous Orbital Implant in Enucleated and Eviscerated Patients

Objectives: To assess the overall mental health of enucleated or eviscerated patients after high-density porous polyethylene OCULFIT implantation and external prosthesis over a 1-year follow-up. Methods: Patients with an indication of enucleation or evisceration with OCULFIT implantation were included in a prospective study. The patients completed four questionnaires regarding mental health at three different visits (baseline, 3–6 months, and 9–12 months post-surgery). The questionnaires used were the following: SF-12 for multidimensional health-related quality of life (scale 0–100); Rosemberg self-esteem scale (scale 0–40); Patients Health Questionnaire-4 (PHQ-4) (scale 0–6); and a Lifetime Major Depression and Anhedonia questionnaire (categorised in groups with/without symptoms). Results: A total of 33 patients (16 enucleations and 17 eviscerations) were included in the study. The physical domain of the SF-12 questionnaire did not change between visits, but the mental domain significantly improved from the baseline to the last visit (41.71 ± 12.72 vs. 46.80 ± 10.68, p = 0.04). The number of patients with high, moderate, and low self-esteem (Rosemberg scale) was similar between the baseline and the last visit. The depression and anxiety scores of the PHQ-4 were not significantly different among visits. The number of patients with no symptoms (depression or anhedonia) improved from the baseline (42.2%) throughout the follow-up (66.7% at the last visit). Conclusions: OCULFIT orbital implant and external prosthesis placement maintained and/or improved the quality of life related to mental health in eviscerated and enucleated eyes. The number of patients with no symptoms improved from the baseline throughout the follow-up. The patients’ self-esteem was already high before implantation and remained stable over the follow-up.

Auricle reconstruction with autologous costal cartilage versus polyethylene implants in microtia patients: a meta-analysis.

Auricle reconstruction is among the most challenging procedures in plastic and reconstructive surgery, and the choice of framework material is a critical decision for both surgeons and patients. This meta-analysis compared the outcomes of autologous auricle reconstruction using costal cartilage with those of alloplastic reconstruction using porous polyethylene implants. A literature review was conducted using the PubMed and Embase databases to retrieve articles published between January 2000 and June 2024. The outcomes analyzed included postoperative complications such as framework exposure, infection, skin necrosis, hematoma, and hypertrophic scars, as well as patient satisfaction. The proportions of reconstructive outcomes from each selected study were statistically analyzed using the "metaprop" function in R software. Fourteen articles met our inclusion criteria. The group undergoing polyethylene implant reconstruction exhibited higher rates of framework exposure, infection, and skin necrosis, whereas the autologous reconstruction group experienced higher rates of hematoma and hypertrophic scars. Of all the complications, framework exposure was the only one to show a statistically significant difference between the two groups (p < 0.0001). In terms of patient satisfaction, those who underwent autologous cartilage reconstruction reported a higher rate of satisfaction, although this difference did not reach statistical significance in the meta-analysis (p = 0.076). There is no statistically significant difference in postoperative complications such as infection, hematoma, skin necrosis, and hypertrophic scars between auricle reconstructions using autologous costal cartilage and those using polyethylene implants. However, reconstructions with polyethylene implants show a significantly higher rate of framework exposure.

Biocompatibility and osteogenic capacity of additively manufactured biodegradable porous WE43 scaffolds: An in vivo study in a canine model

Magnesium is the most promising absorbable metallic implant material for bone regeneration and alloy WE43 is already FDA approved for cardiovascular applications. This study investigates the cyto- and biocompatibility of novel additively manufactured (AM) porous WE43 scaffolds as well as their osteogenic potential and degradation characteristics in an orthotopic canine bone defect model. The cytocompatibility was demonstrated using modified ISO 10993-conform extract-based indirect and direct assays, respectively. Additionally, degradation rates of WE43 scaffolds were quantified in vitro prior to absorption tests in vivo. Complete blood cell counts, blood biomarker analyses, blood trace element analyses as well as multi-organ histopathology demonstrated excellent biocompatibility of porous y WE43 scaffolds for bone defect repair. Micro-CT analyses further showed a relatively higher absorption rate during the initial four weeks upon implantation (i.e., 36 % ± 19 %) than between four and 12 weeks (41 % ± 14 %), respectively. Of note, the porous WE43 implants were surrounded by newly formed bony tissue as early as four weeks after implantation when unmineralized trabecular ingrowth was detected. After 12 weeks, a substantial amount of mineralized bone was detected inside and around the gradually disappearing implants. This first study on AM porous WE43 implants in canine bone defects demonstrates the potential of this alloy for in vivo applications in humans. Our data further underscore the need to control initial bulk absorption kinetics through surface modifications.

Do the porous custom implants have a position consistent with the planning and allow anatomical reconstruction of hip center of rotation in complex acetabular revisions Paprosky III?

IntroductionIn revision total hip arthroplasty (THA), the advent of porous custom-made triflange acetabular implants with 3D scan planning offers a new perspective to improve implantation accuracy and anatomical restoration of the center of rotation (COR). This issue was investigated using CT-scan as the measurement tool, but in limited series (±10 cases) and without investigating the factors that may influence errors in positioning. Therefore we performed a retrospective study aiming to: (1) assess the placement accuracy of such implants with respect to the preoperative planning, (2) examine whether the volume of bone to be resected in order to apply the implant had an impact on this accuracy, (3) assess if errors in position at surgery had any influence on function, complications and survival. HypothesisPreoperative planning could be accurately reproduced when implanting porous custom-made acetabular implants, and that accuracy would decrease in proportion to the volume of bone to be resected MethodTwenty patients undergoing THA revision with porous custom-made acetabular implants were included in this single-center retrospective study. Mean follow-up was 17.9 months ± 9.4 [2–45.1]. Preoperative planning was performed using 3D scanographic modeling. A post-operative CT scan was performed to assess implantation accuracy in terms of orientation and COR restitution. Demographic data, Oxford scores, complications and survival were recorded. ResultsMean deviation from the preoperative planning in inclination, anteversion and rotation were 4.3 ° ± 2.5, 6.1 ° ± 4.7, and 7 ° ± 4.6, respectively. Restoration of the COR showed a mean deviation of 2.1 ± 1.3 mm anteroposteriorly, 2.5 ± 2 mm mediolaterally and 2.2 ± 1.3 mm proximodistally. In total, 45% (9/20) of implants were positioned with perfect restoration of orientation (±10 °) and COR (±5 mm). The mean planned bone resection was 8.1 ± 4.9 cm3, with placement accuracy and COR restitution decreasing significantly when the volume of bone to be resected exceeded 2.7 cm3. One dislocation was found (5%, 1/20). Survival at last follow-up was 100%, the mean Oxford score at follow-up was 31.7 ± 7.9 [16–52], without being influenced by errors in position or COR restitution. ConclusionIn total 45% of the implants restored an orientation and a COR as planned, particularly when the volume of bone to be resected is less than 2.7 cm3. Although these are complex cases with large amounts of bone loss, 3D manufacturing could give us hope of greater precision. The link between better precision and low bone resection volume could be an area to develop with the manufacturer in order to improve results. Level of evidenceIII; diagnostic using CT in transversal retrospective study

Electrophoretic Deposition of Chitosan Coatings on the Porous Titanium Substrate.

Medicine is looking for solutions to help implant patients recover more smoothly. The porous implants promote osteointegration, thereby providing better stabilization. Introducing porosity into metallic implants enhances their biocompatibility and facilitates osteointegration. The introduction of porosity is also associated with a reduction in Young's modulus, which reduces the risk of tissue outgrowth around the implant. However, the risk of chronic inflammation remains a concern, necessitating the development of coatings to mitigate adverse reactions. An interesting biomaterial for such modifications is chitosan, which has antimicrobial, antifungal, and osteointegration properties. In the present work, a porous titanium biomaterial was obtained by powder metallurgy, and electrophoretic deposition of chitosan coatings was used to modify its surface. This study investigated the influence of ethanol content in the deposition solution on the quality of chitosan coatings. The EPD process facilitates the control of coating thickness and morphology, with higher voltages resulting in thicker coatings and increased pore formation. Ethanol concentration in the solution affects coating quality, with higher concentrations leading to cracking and peeling. Optimal coating conditions (30 min/10 V) yield high-quality coatings, demonstrating excellent cell viability and negligible cytotoxicity. The GIXD and ATR-FTIR analysis confirmed the presence of deposited chitosan coatings on Ti substrates. The microstructure of the chitosan coatings was examined by scanning electron microscopy. Biological tests showed no cytotoxicity of the obtained materials, which allows for further research and the possibility of their use in medicine. In conclusion, EPD offers a viable method for producing chitosan-based coatings with controlled properties for biomedical applications, ensuring enhanced patient outcomes and implant performance.