Search Results (157)

Orthodontic implants (OIs) are endosseous devices designed to provide stable skeletal anchorage in orthodontic treatment. A variety of terms have been proposed for these devices; however, such terminology may lead to OIs being confused with conventional dental implants. Therefore, the similarities and distinctions between OIs and dental implants will be examined in this research. Three representative clinical cases will be presented, illustrating the application of OIs for mandibular incisor teeth lingualizations, distalization of a maxillary canine tooth, and palatal flap protection for palatoschizis closure in a cat, describing a custom-made protection shield held in place with four OIs. This article will cover the criteria for OI selection, the determination of optimal insertion sites, and the placement technique. Given that a key prerequisite for a successful outcome is primary stability, several complications may occur such as local inflammation, injury to adjacent anatomical structures, implant fracture, loss of stability, or challenges in attaching elastic chains due to interference from surrounding soft tissues. The prevention and management of such complications will be addressed. Full article

Background: Megaprosthetic replacement is widely used following tumour resection but remains challenged by periprosthetic joint infection (PJI) and variable functional outcomes. This narrative review aims to summarise current evidence on infection rates, prevention strategies, and functional outcomes following proximal humerus megaprosthetic reconstruction. We hypothesise that antibacterial coatings and improved soft-tissue techniques reduce infection rates and enhance functional recovery. Methods: A comprehensive narrative review of PubMed, Web of Science, and the Cochrane Library was performed using the terms proximal humerus, shoulder, bone tumor, sarcoma, neoplasm, infection, megaprosthesis, and endoprosthetic replacement. Reference lists were screened manually. Case reports and series with fewer than five patients were excluded. Twenty-seven clinical studies (more than 1100 patients; mainly osteosarcoma, chondrosarcoma, and metastatic lesions) were included and qualitatively analyzed. Results: The reported infection rates ranged from 4% to 20%, with higher risk in patients receiving adjuvant therapy. Silver-coated implants reduced PJI compared with uncoated designs (e.g., 11.2% → 9.2% in primary implants; 29.2% → 13.7% in revisions) without systemic toxicity. Alternative antibacterial coatings (e.g., silver- or copper-enriched hydroxyapatite) showed promising early results but remain supported by limited clinical data. Soft-tissue stabilization with Trevira tube or synthetic mesh improved joint stability and did not increase infection risk. Functional outcomes, usually assessed by MSTS or TESS, were moderate to good (≈60–80%) overall, with better scores when the deltoid and axillary nerve were preserved or when reverse total shoulder arthroplasty was possible. Conclusions: Proximal humerus megaprosthetic reconstruction benefits from meticulous soft-tissue handling, selective use of antibacterial technologies, and multidisciplinary management. The current literature is mainly retrospective, heterogeneous, and non-comparative. Prospective multicenter studies are needed to clarify the long-term effectiveness of silver or alternative coatings, soft-tissue reconstruction techniques, and emerging custom-made 3D-printed prostheses. Full article

Background/Objectives: Postoperative infection is a significant complication following cranioplasty procedures. This study aimed to assess infection risk factors and clinical outcomes in patients undergoing cranioplasty with custom-made porous hydroxyapatite (PHA) implants, with a particular focus on treatment strategies used to manage infections and avoid implant explantation. Methods: This retrospective multicenter analysis included 984 patients who underwent PHA cranioplasty as part of a post-market clinical follow-up. Clinical data included demographics, surgical characteristics, infection features, microbiological results, infection management strategies, and outcomes. Associations with infection risk and implant explantation were assessed using chi-square tests. Results: Seventy-six patients (7.7%) developed postoperative infections. Infection risk was significantly associated with second-line procedures (p = 0.011) and implant location (p = 0.037). Most infections were superficial (92.1%) and early-onset (≤2 months from the surgery, 61.9%), with Staphylococcus spp. as the predominant pathogens. Explantation occurred in 77.6% of infected cases. The infection management strategy—whether initial conservative treatment with antibiotics alone (n = 18 of which 11.1% explanted) or surgical reoperation (n = 58 of which 93.8% explanted)—along with surgical cleaning and local (in situ) antibiotic use alone, was significantly associated with explantation outcomes (all p < 0.001). Among 18 patients treated with systemic antibiotics alone, 88.9% retained their implants. Notably, all successful cases had received broad-spectrum antibiotics for at least 4 weeks. Local antibiotic therapy was administered in 13 patients; no explants occurred among those who also received prolonged systemic treatment. Pathogen type was not significantly associated with the risk of explantation. Conclusions: Prolonged systemic antibiotic therapy, especially when combined with local treatment, may allow implant retention in selected infections, supporting individualized, conservative management strategies. Full article

Background: Severe glenoid bone loss presents a major challenge in both primary and revision reverse shoulder arthroplasty (RSA). Standard implants often fail to achieve reliable fixation in these cases. Custom-made, 3D-printed glenoid components have emerged as a potential solution, offering anatomically tailored fit and fixation. This study evaluates the clinical and radiographic outcomes of custom-made glenoid implants in managing severe glenoid bone loss. Methods: A retrospective, multicenter study was conducted on 23 shoulders (11 primary and 12 revision RSAs) that received a custom-made glenoid component using the Enovis ProMade System (San Daniele del Friuli, Udine, Italy) between 2017 and 2022, with a minimum follow-up of 24 months. Preoperative planning utilized CT-based 3D modeling to design implants with patient-specific instrumentation. Clinical outcomes (ROM, pain, Constant–Murley score) and radiographic results were assessed. Statistical comparisons were made between primary and revision groups. Results: Both groups demonstrated significant improvements in shoulder mobility, pain relief, and Constant–Murley scores (all p < 0.001), with no significant differences between primary and revision groups in delta scores. Radiographically, no loosening was observed, with minimal radiolucent lines and low complication rates. Four cases of instability occurred, all in the revision group, with only one requiring conversion to hemiarthroplasty. No differences in radiographic outcomes were observed between groups. Conclusions: Custom-made glenoid implants provide a reliable solution for severe glenoid bone loss in both primary and revision RSA, yielding consistent functional improvement and implant stability. Further prospective studies with larger cohorts and long-term follow-up are warranted to confirm these findings and assess cost-effectiveness. Full article

During the investigation, the effect of screw tightening torque on the potential loosening of screws under load was examined in the case of custom-made subperiosteal implants. The study focused on the connection screws between the implant components, testing the commonly applied tightening torques of 15 Ncm and 30 Ncm. Mastication was simulated using a custom-designed, PLC-controlled testing device, which allowed for the reproduction of variable numbers, forces, and speeds of bite cycles. With this device, six different scenarios were tested, including 500, 2000, and 10,000 bite cycles, under both constant and variable bite forces. A caliper was used to record potential length changes of the screws, force sensors measured the bite forces, and calibrated torque screwdrivers were used to verify the loosening torques. Based on the analysis of the measured data, it was concluded that for the M1.8 screws tested, a tightening torque of 15 Ncm does not provide sufficient resistance against loosening, whereas 30 Ncm offers adequate stability. Full article

Introduction: Two-stage revision with an antibiotic-loaded, temporary static cement spacer is a common treatment for periprosthetic joint infection (PJI) of the knee. However, limited data exists on in vivo antibiotic elution kinetics after spacer implantation. This pilot study uses the technique of microdialysis (MD) to collect intra-articular knee samples. The aim was to evaluate MD as an intra-articular sampling method to detect spacer-eluted antibiotics within 72 h after surgery and to determine whether they show specific elution kinetics. Methods: Ten patients (six male, four female; age median 71.5 years) undergoing two-stage revision for knee PJI were included. A MD catheter was inserted into the joint during explantation of the infected inlying implant and implantation of a custom-made static spacer coated with COPAL cement (0.5 g gentamicin (G) and 2 g vancomycin (V)). Over 72 h postoperatively, samples were collected and analyzed for spacer-eluted antibiotics, intravenously administered antibiotics (e.g., cefazolin and cefuroxime), metabolic markers (glucose and lactate), and Interleukin-6 (IL-6). Local and systemic levels were compared. Results: All catheters were positioned successfully and well tolerated for 72 h. Antibiotic concentrations in MD samples peaked within the first 24 h (G: median 9.55 µg/mL [95% CI: 0.4–17.36]; V: 37.57 µg/mL [95% CI: 3.26–81.6]) and decreased significantly over 72 h (for both p < 0.05, G: 4.27 µg/mL [95% CI: 2.26–7.2]; V: 9.69 µg/mL [95% CI: 3.86–24]). MD concentrations consistently exceeded blood levels (p < 0.05), while intravenously administered antibiotics showed higher blood concentrations. Glucose in MD samples decreased from 17.71 mg/dL to 0.89 mg/dL (p < 0.05). IL-6 and lactate concentrations showed no difference between MD and blood samples. Conclusions: Monitoring antibiotics eluted by a static spacer with intra-articular MD for 72 h is feasible. Gentamicin and vancomycin levels remained above the minimal inhibitory concentration. Differentiating infection from surgical response using metabolic and immunological markers remains challenging. Prolonged in vivo studies with MD are required to evaluate extended antibiotic release in two-stage exchanges. Full article

Background/Objectives: Severe jawbone atrophy, particularly in elderly or medically compromised patients, presents a significant challenge for conventional implant placement. In cases where bone augmentation is not feasible, alternative techniques—such as short, narrow, tilted, and zygomatic implants—may be indicated for the rehabilitation of the atrophic jaw. Subperiosteal implants have re-emerged as a further viable alternative, especially with recent advancements in digital planning and custom fabrication. This study aims to evaluate the clinical outcomes and complications associated with subperiosteal implants through a literature review and a supporting case series, and to propose clinical preliminary guidelines for their use. Methods: Fourteen studies—including case reports, case series, retrospective studies, and systematic reviews—were analyzed to assess the effectiveness and risk profile of subperiosteal implants. Additionally, we present a case series of nine patients with advanced vertical and horizontal alveolar bone atrophy treated using custom-made, digitally-designed subperiosteal implants. Surgical techniques, prosthetic workflows, and complications were recorded and assessed. Results: Subperiosteal implants were found to be particularly suitable for patients with narrow alveolar crests and severe atrophy where traditional implants are contraindicated. Literature and case series data indicated favorable outcomes, with early complications such as soft tissue inflammation and prosthetic misfit being manageable. A low complication rate was recorded in our series, with digital workflows contributing to improved implant fit and reduced technical errors. Conclusions: Subperiosteal implants could offer an effective solution for complex atrophic cases, provided that patient selection, surgical precision, and prosthetic design are meticulously managed. Based on our findings, clinical recommendations are proposed to guide their application in contemporary practice. Full article

Background/Objectives: We sought to demonstrate the versatility and economy of physician-modified endograft (PMEG) fenestrated endovascular aortic repair (FEVAR) based on the Treo (Terumo Aortic) platform for patients referred for custom-made device (CMD) FEVAR due to a complex abdominal aortic aneurysm (CAAA). Endovascular planning was performed utilizing a standardized design incorporating all visceral arteries with a low supra-celiac landing zone. The pure cost of the aortic components was compared between the PMEG and CMD designs. Methods: A total of 39 consecutive patients treated with CMD FEVAR due to a CAAA between September 2018 and December 2023 were recruited at a tertiary vascular center for a retrospective evaluation. Endovascular planning was performed on readily available computed tomography angiography (CTA) datasets using 3Mensio Vascular (Pie Medical Imaging) software. The actual cost of the major components was compared between the implanted CMD platform produced by Cook and the planned Treo-based PMEG repair. Results: A total of 155 fenestrations were planned on 3 triple-, 34 quadruple-, and two quintuple-fenestrated devices. The 90 mm distance between the proximal edge and the flow divider of the 120 mm long main body of the Treo graft allowed for the placement of all necessary fenestrations of the target arteries without the need to reduce the 3 cm supra-celiac landing zone while also preserving a safety distance of >1 cm to the flow divider. The costs of the components were EUR 33896 for CMD and EUR 8878 for a PMEG. Conclusions: This retrospective study suggests that a quadruple-fenestrated PMEG based on the Treo bifurcation is a highly versatile alternative with a significant price advantage over custom-made devices for the treatment of complex abdominal aortic aneurysms. Full article

Temporomandibular joint replacement is a critical intervention for severe temporomandibular joint disorders, enhancing pain levels, jaw function and overall quality of life. In this study, we compare two finite element method-based simulation workflows from both academic and industrial perspectives, focusing on a patient-specific case involving a custom-made temporomandibular joint prosthesis. Using computed tomography data and computer-aided design data, we generated different 3D models and performed mechanical testing, including wear and static compression tests. Our results indicate that the academic workflow, which is retrospective, purely image-based and applied post-operatively, produced peak stress values within 9–20% of those obtained from the industrial workflow. The industrial workflow is prospective, pre-operative, computer-aided design-based and guided by stringent regulatory standards and approval protocols. Observed differences between workflows were attributed primarily to distinct modelling assumptions, simplifications and constraints inherent in each method. To explicitly quantify these differences, multiple additional models were generated within the academic workflow using partial data from the industrial process, revealing specific sources of variation in stress distribution and implant performance. The findings underscore the potential of patient-specific simulations not only to refine temporomandibular joint prosthesis design and enhance patient outcomes, but also to highlight the interplay between academic research methodologies and industrial standards in the development of medical devices. Full article

Background: Modern dentistry demands accurate finish line designs for abutments. CAD/CAM systems enable the fabrication of thin prosthetic structures to fulfill this requirement. The aim of this study is to research the mechanical resistance of customized implant abutments with different types of marginal design in laboratory environment. The null hypothesis is there is no difference in fatigue loading and compression strength in custom implant abutments with chamfer or vertical marginal design. Methods: The study model includes 60 specimens of implant suprastructures, organized into four test groups, by the margin design and used material: Group A—suprastructures, made of monolithic zirconia implant crown and titanium custom abutment with vertical marginal design; Group B—suprastructures, monolithic lithium disilicate implant crown and titanium custom abutment with vertical marginal design; Group C—suprastructures, made of monolithic zirconia implant crown and titanium custom abutment with chamfer marginal design; and Group D—suprastructures, made of monolithic lithium disilicate implant crown and titanium custom abutment with chamfer marginal design. All samples were subjected to fatigue loading test in chewing Simulator CS-4 (SD-Mechatronik, Westerham, Germany) for 1250,000 cycles, at a frequency of 2 Hz. The specimens, which survived, was conducted to compressive strength test in universal testing machine Instron M 1185 (Instron, Norwood, MA, USA). Results: The results analysis highlighted Group A as the most resistant to compressive forces (4411 MPa). Group D was with lowest values (1864 MPa)—twice than Group A. Group B (3314 MPa) had lower results than Group A, but higher than Groups C (3130 MPa) and D. Conclusion: Compression strength significantly depends on the choice of marginal design of implant abutments. Vertical margin design has better performance, that chamfer one. Full article

Background/Objectives: The structural integrity and strength of the transgingival soft tissue seal around dental implant surfaces remain critical challenges. Therefore, animal models should include all three implant/tissue interfaces: bone, connective tissue, and epithelium. Thus, we sought to explore the rabbit mandibular diastema as a site for candidate intra-oral implant placement. Methods: Ninety-six custom mini-implants (with one of four different surfaces: machined, acid-etched, and with or without a nanotube coating) made from titanium 6/4 alloy were placed in the mandibular diastemas of twenty-four 16-week-old New Zealand white rabbits, with the implant collar above the alveolar crest. After 7, 21, and 42 days, the bony and connective tissue/implant interfaces were examined by light and scanning electron microscopy (SEM). Results: Of ninety-six implants, eight implants were found exposed to the oral cavity, with no evidence of soft tissue inflammation, suggesting that transmucosal implant placement would have been feasible. No significant differences were observed in collagen fiber orientation and fibrous tissue thickness by polarized light microscopy. However, SEM images showed that at all three time points, topographically complex nanotube surfaces had a profound effect on soft tissue peri-implant deposition, although functionally oriented collagen fibers were not identified attached to the implant surface. These surfaces also showed reparative peri-implant bone in the collar region. An intramembranous form of de novo bone formation was observed, together with tartrate-resistant acid-phosphatase-positive osteoclasts and multinucleate giant cells in the peri-implant endosseous compartment. Conclusions: Our results demonstrate that the rabbit mandibular diastema provides an intra-oral method of implant placement without the necessity of an extra-oral approach, tooth extractions, or bone augmentation procedures. Furthermore, given that three implant tissue interfaces can potentially be studied (bone, connective tissue, and epithelium) this model provides advantages over more traditional implant placement sites in the appendicular skeleton. Full article

Background/Objectives: A novel 3D-printed, bioresorbable bone graft, made of nanohydroxyapatite (nHAP) covered by poly(lactide-co-glycolide) (PLGA), showed strongly expressed osteoinductive properties in our previous investigations. The current study examines its application in the dual regeneration of bone and cartilage by combining with nHAP gel obtained by nHAP enrichment with hydroxyethyl cellulose, sodium hyaluronate, and chondroitin sulfate. Methods: In the in vitro part of the study, the mitochondrial activity and osteogenic and chondrogenic differentiation of stem cells derived from apical papilla (SCAPs) in the presence of nHAP gel were investigated. For the in vivo part of the study, three rabbits underwent segmental osteotomies of the lateral condyle of the femur, and defects were filled by 3D-printed grafts customized to the defect geometry. Results: In vitro study revealed that nHAP gel displayed significant biocompatibility, substantially increasing mitochondrial activity and facilitating the osteogenic and chondrogenic differentiation of SCAPs. For the in vivo part of the study, after a 12-week healing period, partial resorption of the graft was observed, and lamellar bone tissue with Haversian systems was detected. Histological and stereological evaluations of the implanted grafts indicated successful bone regeneration, marked by the infiltration of new bone and cartilaginous tissue into the graft. The existence of osteocytes and increased vascularization indicated active osteogenesis. The hyaline cartilage near the graft showed numerous new chondrocytes and a significant layer of newly formed cartilage. Conclusions: This study demonstrated that tailored 3D-printed bone grafts could efficiently promote the healing of substantial bone defects and the formation of new cartilage without requiring supplementary biological factors, offering a feasible alternative for clinical bone repair applications. Full article

Background: Technological advancements have made three-dimensional printing prevalent in orthopedic surgery. It facilitates the production of customized implants and tailored patient instruments, enhancing surgical planning and results. This review focuses on the uses and effectiveness of patient-specific products manufactured using three-dimensional printing in ankle surgery. Methods: A search of databases—PubMed, Embase, Cochrane Library, and Google Scholar—yielded 41 articles for review. Results: Total talus replacement offers a viable alternative to standard treatments like arthrodesis and total ankle arthroplasty. Custom implants and patient-specific instrumentation in total ankle arthroplasty procedures guarantee a tailored fit and accurate alignment. For arthrodesis, three-dimensional printing enables the production of cages, effectively solving issues associated with conventional bone grafts, such as poor bone quality, significant defects, and nonunion. Additionally, patient-specific instrumentation facilitates the swift and accurate placement of Kirschner wires at the correct sites. When performing supramalleolar osteotomy, patient-specific instrumentation leads to shorter operation times, reduced blood loss, and less radiation exposure. Conclusions: Three-dimensional printing is increasingly employed in ankle surgeries, and as technology advances, it is anticipated to become critical for addressing complex ankle issues. Full article

The treatment of Paprosky Type III acetabular defects is a significant challenge in orthopedic surgery, as standard components often do not fit properly. This study aims to evaluate the biomechanical efficacy of a custom 3D-printed PEEK acetabular prosthesis compared to a conventional titanium implant. A 3D model of the pelvis was created using a computed tomography scanner and a custom-made acetabular implant was designed. Finite element analysis (FEA) was performed using Ansys Workbench to evaluate the stress and strain distribution of two materials on the pelvic bone. The results showed that the titanium prosthesis model had less strain transmitted to the bone, while the PEEK model had better stress transmission and bone stimulation. The use of custom implants reduced the risk of stress shielding, potentially improving long-term bone health. Three-dimensional-printed acetabular prostheses therefore offer significant advantages over traditional implants, suggesting improved implant stability and reduced failure rates. Full article

The advent of 3D printing technology has revolutionized various manufacturing sectors, including the medical field, particularly in the production of prosthetic limbs. Traditional prosthetic manufacturing processes are often time-consuming and expensive, causing amputees to endure long waiting periods and high costs. In contrast, 3D printing offers a rapid, cost-effective alternative, enabling the creation of custom-made prosthetics tailored to the specific needs and measurements of each wearer. Integrating 3D printing technology into prosthetics and orthopedics has ushered in a new era of customization and innovation. This advanced approach facilitates the creation of personalized prosthetics and bone replacements tailored to individual patients’ needs. With the latest advancements in software and 3D printing, the use of custom orthopedic implants for complex surgical cases has gained significant popularity. This paper explores the advantages of using 3D printing for prosthetic limb production, highlighting its ability to significantly reduce the production time and costs while maintaining high functionality and quality. By leveraging 3D scanning and computer-aided design (CAD), precise digital models of a patient’s residual limb can be created, ensuring a perfect fit and improved comfort. Additionally, the flexibility of 3D printing allows for the incorporation of advanced materials and design features, enhancing the durability and performance of the prosthetics. The study also examines the potential for 3D printing to democratize access to prosthetic care, especially in low-resource settings. The affordability and accessibility of 3D printers, coupled with open-source designs, empower local communities and healthcare providers to produce prosthetics on demand, reducing dependency on centralized manufacturing facilities. By addressing the current limitations and challenges, including material constraints and regulatory hurdles, this paper highlights the transformative impact of 3D printing on the prosthetics industry. Full article