Implants In Orthopaedic Surgery Research Articles

The effects of adding Si3N4 as a nitrogen source on the properties of Ni-Free Co-28Cr-6Mo-xN alloy powders developed by mechanical alloying

Co-Cr-Mo alloys, which also contain Ni, are often used as materials for implants in orthopedic surgery due to their excellent mechanical properties and resistance to corrosion. However, when these alloys are implanted into the body, they can release nickel ions into the host tissues, which can pose health risks over time. To address this issue, nitrogen can be substituted for nickel. This study involves the synthesis of cobalt-based alloy powders, following the chemical composition specified by ASTM F1537, using different percentages of silicon nitride as a nitrogen source via the mechanical alloying method in an argon atmosphere. The effects of increasing silicon nitride content on the particle morphology, particle size, phase transformations, microstructure, and hardness of the synthesized powders were investigated using XRD, SEM, TEM, and microhardness tests. The results obtained from the X-ray diffraction analysis indicate that the alloying process was conducted effectively. It was observed that the silicon nitride underwent decomposition, and a portion of its nitrogen reacted with chromium to form the chromium nitride phase. Additionally, it was observed that an increase in the silicon nitride content resulted in a decrease in crystallite size and an increase in lattice strain. Adding silicon nitride in varying percentages resulted in crystal sizes within the nanometer range. The SEM results indicated that the size of powder particles decreased with an increase in the content of silicon nitride, and there was a more uniform distribution of particle sizes, with less variation in size. The TEM images showed that all percentages of silicon nitride resulted in a fine-grained polycrystalline phase, where the size of the crystallites decreased with an increase in the amount of silicon nitride. The corresponding SAED patterns supported this observation. Moreover, the hardness of the material increased as the silicon nitride content increased.

Bio-integrative vs Metallic Screws in Calcaneus Osteotomies: A Non-Inferiority Randomized Clinical Trial

Category: Hindfoot; Other Introduction/Purpose: The use of bio-integrative implants in orthopedic surgery is growing exponentially. Advantages, such as reduced implant-related artifact production, lower removal rates, and superior bone interaction, have been advocated. However, while many biomechanical and histological reports could sustain its structural and biological properties, only some clinical studies were produced that could support its use. Therefore, this trial intended to determine the bio-integrative screws' capacity to reach the same clinical and radiographical outcomes of current metallic screws in calcaneus osteotomies. Our main hypothesis was that metallic and bio-integrative screws would not present differences when comparing bone healing and complications. Methods: This was a single center, in parallel groups, randomized non-inferiority clinical trial (NCT05018130) that included patients undergoing a calcaneal sliding osteotomy from November 2021 to January 2023. Patients were randomized in a 1 to 1 ratio by software in the metallic or bio-integrative groups, and allocation occurred after anesthesia was carried out. Surgeries were performed by a single surgeon respecting the same technique, using two canulated 4mm screws, either titanium or fiber, according to the treatment group. The primary outcome was determined by bone using weight-bearing computed tomography (WBCT) in the 6th postoperative week. At least 50% of bone trabeculae crossing the osteotomy site needed to be observed to be considered positive. Secondary outcomes included minor and major complications and bone healing, assessed in the 2nd, 4th, 6th, 12th, 24th, and 48th weeks of follow-up. Two assessors performed readings. Between-group differences were measured with ANOVA and chi-square tests. Results: After twenty-nine patients were assessed initially, 22 subjects were found eligible and included in the study. Groups were similar demographically (ps>0.37), with ten patients allocated to the bio-integrative and 12 to the metallic group. The mean follow- up was 31.64 weeks (min 6; max 48) with no losses through the endpoints. Considering WBCT bone healing at six weeks, the bio (80%) and the metallic (75%) groups had similar rates (p=0.58). At 12 weeks, bone healing was slightly higher in the bio-integrative group (100% vs. 92%; p=0.004). No major complications were observed. Minor complications were similar between groups (10% in bio; 16% in metallic; p=0.56) and composed of superficial infections (one bio, one metallic) and delayed wound healing (one metallic), all resolved by six weeks. Conclusion: Bio-integrative screws presented similar results to metallic screws when used in calcaneus osteotomies, considering bone healing and complications. No differences were found in a medium to long-term follow-up, and no major complications were reported. This non-inferiority clinical trial could contribute to the body of literature supporting the use of bio-integrative screws in clinical practice. Larger and longer trials are necessary to determine the superiority of any implant and its impact on orthopedic surgery.

Prediction of mechanical strength of magnesium alloy AZ31 with calcium addition using a neural network based model

The aim of the research is to develop a neural network model to predict the mechanical strength of AZ31 magnesium alloy in addition with Calcium. This would help researchers or academicians to fabricate the magnesium alloy AZ31+x wt. % Ca which finds more importance in making biodegradable implants in orthopedic surgery. As the yield strength of human bone lies between 104.9 – 114.3 MPa whereas for pure Mg it is very lesser, it is needed to make alloys suitable for biomedical applications which are to be satisfied with their mechanical properties and biocompatibility. An artificial neural network-based model is used to predict the mechanical properties of Mg alloys AZ31+x wt. % Ca with compositions of Al, Zn, Mn and Ca as countable parts with various proportions. The compositions and properties of twenty different as cast alloys were used for training and prediction of the desired mechanical properties using Artificial Neural Network and the outputs are compared with the experimental results. The results show that the Levenberg-Marquardt (LM) algorithm serves better in prediction of mechanical properties of Mg alloys AZ31 and AZ31+1 wt. % Ca. Also the results were found significant at 90%, 95% and 99% confidence limits.

Karakterizacija prevlake cirkonijum oksida stabilizovanog cerijum i itrijum oksidom deponovane na veznoj prevlaci nikl hrom aluminijum kobalt itrijum oksid

Zirconium dioxide ZrO2 is used as a basic material for thermal barriers and as a biomaterial for manufacturing parts for hip implants in orthopedic surgery and in dentistry for making crowns. Use of ZrO2 ceramics as an insulating material and biomaterial is due to its good chemical and dimensional stability, mechanical strength, toughness and elastic modulus. The aim of this study was to analyze the characteristics of zirconium oxide coating of stabilized cerium and yttrium oxide deposited by atmospheric plasma spraying (APS) process on the bond coating of nickel chromium cobalt yttrium oxide. Coatings were deposited on cold substrates and on substrates preheated to 180°C. Composite powder nickel chromium/aluminum/cobalt/yttrium oxide was used for the production of bond layers and for the ceramic layers zirconium oxide stabilized with cerium and yttrium oxide powder. Testing the quality of coatings was done by measuring microhardness of layers using the HV method and for bond tensile strength of the coating system tensile testing was applied. Metallographic evaluation of the share of pores in the bond and ceramic layers was performed with image analysis - processing of images from a light microscope. Powder particle morphology and EDS analysis were performed on the SEM. The obtained results confirm that the preheating temperature of the substrate has a significant impact on structural mechanical properties of the tested coatings system.

Weight-Bearing CT Hounsfield Unit Algorithm Assessment of Calcaneal Osteotomy Healing: A Prospective Study Comparing Metallic and Bio-Integrative Screws

Category: Basic Sciences/Biologics; Hindfoot; Other Introduction/Purpose: The use of bio-integrative implants in orthopedic surgery is growing rapidly. While many biomechanical and histological studies have been able to demonstrate their structural and biological properties, few clinical reports are available to support their advantages, such as good osteosynthesis, lower rates of removal, and diminished implant-related artifact in imaging studies. This clinical information is vital to providers when choosing the proper material and planning postoperative treatment. Hounsfield Units (HU) algorithms have been used as an objective assessment of joint space width. This pilot data analysis intends to test the capacity of the bio-integrative screws in reaching similar radiographical outcomes of the current metallic screws when analyzing medial displacement calcaneus osteotomies (MDCO). Our hypothesis is that both types of implants would present similar results. Methods: In this prospective comparative IRB-approved study, three patients undergoing MDCO with bio-integrative screws were compared to two patients undergoing the same surgery with metallic screws. Surgeon, primary diagnosis, technique, and displacement were the same for both groups. Patients were assessed using weight-bearing computed tomography at weeks 2, 6, and 12 postoperatively. Using a dedicated software, a 40x40x40mm cube, which defines a volume of interest (VOI), is centered at the osteotomy site. Within the VOI, initial computational analysis focused on image intensity (Hounsfield Units) profiles along lines perpendicular to the osteotomy line, crossing the osteotomy line and spanning approximately 8mm on either side. The HU intensity profiles were recorded, and graphical plots of the HU distributions were generated for each line. The plots were then used to calculate the HU contrast, a proxy for bone healing at the osteotomy site. Results: At 2 weeks, mean HU intensity in the metallic and bio-integrative were respectively 403.25 and 416.28 at the centerline (p=0.312), 513.24 and 386.57 at the inferior (p<0.001), 438.97 and 487.92 at the superior line (p=0.020). With 6 weeks, a mean HU intensity of 318.40 and 414.22 was observed at the centerline (p<0.001), 340.41 to 356.86 (p=0.315) at the inferior, and 401.72 and 449.88 at the superior (p=0.018). At 12 weeks, HU intensity of -85.01 and 64.59 was found at the center (p<0.001), - 111.36 and 139.19 at the inferior (p<0.001), and 225.95 and 166.05 at the superior line respectively (p=0.010). Overall HU units decrease from the second to the twelfth week in both groups (ps<0.001). The contrast was higher in the metallic patients (0.66 to 0.26). Conclusion: Comparison among bone healing between metallic and bio-integrative screws through HU algorithms found similar results. The absence of valleys on the HU graphical plots at 2 weeks postoperatively could be a direct sign of osteotomy compression. Diffuse osteopenia might explain lower amounts at the 12-week evaluation. Maximum HU values were similar, indicating equivalent results at the osteotomy sites, a finding compatible with consolidation. Presence of metallic implants across the osteotomy site hindered both HU intensity and contrast evaluation, presenting a challenge when calculating bone healing through indirect and direct assessments.

Price Transparency and Consumer Perceptions of Generic and Brand-name Implants in Orthopaedic Surgery.

Some have suggested the use of generic surgical implants to curb rising costs of orthopaedic care. However, there is evidence that patients are reluctant to use generic pharmaceuticals as compared to their brand name equivalents for fear of inferior quality. Public perception of the use of generic implants remains unknown. We conducted a cross-sectional survey using Amazon MTurk to identify factors associated with a consumer preference for generic orthopaedic screws and total hip. While much of the public (52%) sees the value of generic implants, fewer (26%) would prefer them in their own care. Most respondents (75%) trust their surgeon's choice, yet the vast majority (83%) want to be informed about the cost of their implant, even if it makes no difference in what they pay. The agreement that older implants are safer than newer implants (OR 1.9 for screws; 2.5 for hip arthroplasty), and that generics are a better value than brand name implants (OR 3.0 for screws; 4.3 for hip arthroplasty) were independently associated with a preference for generics. The observation that many people view generic implants as being a good value, yet fewer would prefer to use them in their own care indicates that concerns over quality may initially limit utilization of generic implants. More evidence is needed to reassure most consumers of the safety and effectiveness of generic implants. Additionally, our findings demonstrate a desire for more implant price transparency when undergoing orthopaedic surgery.

The effect of etched 3D printed Cu-bearing titanium alloy on the polarization of macrophage

3D printed titanium alloys have been widely used as implants in orthopedic surgery and dentistry. In recent years, Cu-bearing titanium alloys have shown great advantages in tissue engineering due to their excellent antibacterial activity and biological effect. In the current study, three alloys, namely, TC4 alloy, TC4-5Cu alloy, and TC4-6Cu alloy were fabricated by the use of selective laser melting (SLM) technology. Acid etching treatment was used to remove the metal powders on the samples and modify the surface of the manufactured alloys. The effect of different etched alloys on the biological behavior of macrophages (RAW 264.7) was studied comprehensively. Results showed that acid etching had no effect on the hydrophilicity, while contributing to the adhesion and polarization of macrophages with a lower ROS level. Moreover, Cu-bearing titanium exhibited better cell adhesion, macrophage polarization potential, and a lower ROS level. In summary, acid etching treatment provided a promising strategy to improve the biological properties of the Cu-bearing titanium alloys by SLM.

Magnesium implants in orthopaedic surgery create a diagnostic conundrum: A radiology case series and literature review.

During a routine post-operative orthopaedic radiograph reading session, repeated unusual radiographic soft tissue and bone appearances became evident. It was discovered that these patients had received biodegradable magnesium implants which have recently been introduced into orthopaedic clinical practice. To the untrained eye, the combination of peri-metallic bone resorption with associated soft tissue gas, could easily be mistaken for post-operative infection. The aim of this study is to properly characterise the radiographic post-operative appearances of biodegradable magnesium orthopaedic hardware. We retrospectively evaluated radiographs of all patients who underwent magnesium screw implantation for fractures over a 6 month period. Four patients, mean age of 9.75 (range: 6-15) years who underwent magnesium screw fixation following fracture were included in the study. Follow up duration was 100 days (range: 75-122) with a mean of 2.5 postoperative radiographs being performed per patient during this period. All cases demonstrated post-operative peri-metallic radiolucency which developed around the magnesium screws on x-ray, which subsequently resorbed over time. Peri-metallic soft tissue gas was observed in all patients. In two cases, magnesium implants fractured. As the use of biodegradable metal implants becomes more common, it is important for radiologists to be aware of their imaging characteristics. Prior to reporting a case, it would be prudent to know if biodegradable screws have been utilised and whether there exists a clinical concern for post-operative infection in patients with these particular implants, in which case it would be critical not to dismiss peri-prosthetic radiolucencies and soft tissue gas as merely a sequela of the natural metal degradation process.

Optimization and evaluation of precision distribution of loaned instruments and implants for orthopedic surgery

Optimization and evaluation of precision distribution of loaned instruments and implants for orthopedic surgery

Three-Dimensionally Printed Ti2448 With Low Stiffness Enhanced Angiogenesis and Osteogenesis by Regulating Macrophage Polarization via Piezo1/YAP Signaling Axis.

Previous studies have found that the novel low-elastic-modulus Ti2448 alloy can significantly reduce stress shielding and contribute to better bone repair than the conventional Ti6Al4V alloy. In this study, the promotion of osteogenesis and angiogenesis by three-dimensionally printed Ti2448 were also observed in vivo. However, these were not significant in a series of in vitro tests. The stiffness of materials has been reported to greatly affect the response of macrophages, and the immunological regulation mediated by macrophages directly determines the fate of bone implants. Therefore, we designed more experiments to explore the role of three-dimensionally printed Ti2448 in macrophage activation and related osteogenesis and angiogenesis. As expected, we found a significant increase in the number of M2 macrophages around Ti2448 implants, as well as better osteogenesis and angiogenesis in vivo. In vitro studies also showed that macrophages pre-treated with Ti2448 alloy significantly promoted angiogenesis and osteogenic differentiation through increased PDGF-BB and BMP-2 secretion, and the polarization of M2 macrophages was enhanced. We deduced that Ti2448 promotes angiogenesis and osteogenesis through Piezo1/YAP signaling axis-mediated macrophage polarization and related cytokine secretion. This research might provide insight into the biological properties of Ti2448 and provide a powerful theoretical supplement for the future application of three-dimensionally printed Ti2448 implants in orthopaedic surgery.

A systematic review of the use of titanium versus stainless steel implants for fracture fixation.

Background:Controversy exists regarding the use of titanium and stainless steel implants in fracture surgery. To our knowledge, no recent, comprehensive review on this topic has been reported.Purpose:To perform a systematic review of the evidence in the current literature comparing differences between titanium and stainless steel implants for fracture fixation.Methods:A systematic review of original research articles was performed through the PubMed database using PRISMA guidelines. Inclusion criteria were English-language studies comparing titanium and stainless steel implants in orthopaedic surgery, and outcome data were extracted.Results:The search returned 938 studies, with 37 studies meeting our criteria. There were 12 clinical research articles performed using human subjects, 11 animal studies, and 14 biomechanical studies. Clinical studies of the distal femur showed the stainless steel cohorts had significantly decreased callus formation and an increased odds radio (OR 6.3, 2.7-15.1; P < .001) of nonunion when compared with the titanium plate cohorts. In the distal radius, 3 clinical trials showed no implant failures in either group, and no difference in incidence of plate removal, or functional outcome. Three clinical studies showed a slightly increased odds ratio of locking screw breakage with stainless steel intramedullary nails compared with titanium intramedullary nails (OR 1.52, CI 1.1-2.13).Conclusion:Stainless steel implants have equal or superior biomechanical properties when compared with titanium implants. However, there is clinical evidence that titanium plates have a lower rate of failure and fewer complications than similar stainless steel implants in some situations. Although our review supports the use of titanium implants in these clinical scenarios, we emphasize that further prospective, comparative clinical studies are required before the conclusions can be made.

Orthopedics and 3D technology in Turkey: A preliminary report.

Objectives In this study, we present the use of case specific three- dimensional (3D) printed plastic models and custom-made acetabular implants in orthopedic surgery.Materials and methods Between March 2018 and September 2020, surgeries were simulated using plastic models manufactured by 3D printers on the two patients with pilon fractures. Also, custom-made acetabular implants were used on two patients with an acetabular bone defect for the revision of total hip arthroplasty (THA).Results More comfortable surgeries were experienced in pilon fractures using preoperative plastic models. Similarly, during the follow-up period, the patients that applied custom-made acetabular implants showed a fixed and well-positioning in radiographic examination. These patients did not experience any surgical complications and achieved an excellent recovery.Conclusion Preoperative surgical simulation with 3D printed models can increase the comfort of fracture surgeries. Also, custom-made 3D printed acetabular implants can perform an important task in patients treated with revision THA surgery due to severe acetabular defects.

Sarcomas Associated with Metal Implants in Orthopedic Surgery and Traumatology. A Report of 3 Cases in 2 Patients

Sarcomas Associated with Metal Implants in Orthopedic Surgery and Traumatology. A Report of 3 Cases in 2 Patients

Implant contamination as a cause of surgical site infection in spinal surgery: are single-use implants a reasonable solution? \u2013 a systematic review

BackgroundIn spine surgery, surgical site infection (SSI) is one of the main perioperative complications and is associated with a higher patient morbidity and longer patient hospitalization. Most factors associated with SSI are connected with asepsis during the surgical procedure and thus with contamination of implants and instruments used which can be caused by pre- and intraoperative factors. In this systematic review we evaluate the current literature on these causes and discuss possible solutions to avoid implant and instrument contamination.MethodsA systematic literature search of PubMed addressing implant, instrument and tray contamination in orthopaedic and spinal surgery from 2001 to 2019 was conducted following the PRISMA guidelines. All studies regarding implant and instrument contamination in orthopaedic surgery published in English language were included.ResultsThirty-five studies were eligible for inclusion and were divided into pre- and intraoperative causes for implant and instrument contamination. Multiple studies showed that reprocessing of medical devices for surgery may be insufficient and lead to surgical site contamination. Regarding intraoperative causes, contamination of gloves and gowns as well as contamination via air are the most striking factors contributing to microbial contamination.ConclusionsOur systematic literature review shows that multiple factors can lead to instrument or implant contamination. Intraoperative causes of contamination can be avoided by implementing behavior such as changing gloves right before handling an implant and reducing the instruments’ intraoperative exposure to air. In avoidance of preoperative contamination, there still is a lack of convincing evidence for the use of single-use implants in orthopaedic surgery.

Is Preoperative Planning for Hip Surgery Using Three-Dimensional Printed Models Associated with Improved Intra- and Postoperative Outcomes? A Systematic Review

AbstractUse of three-dimensional (3D) printed models for preoperative planning, patient-specific surgical guides, and implants in orthopaedic surgery is a burgeoning technology. It has not been established if 3D-printed models for preoperative planning are associated with improved clinical outcomes or if they are cost-effective for hip surgeries including total hip arthroplasty (THA), periacetabular osteotomy (PAO), proximal femoral osteotomy (PFO), and/or hip fractures. The purpose of this study was to conduct a systematic search and literature review to determine if preoperative planning for hip surgery using 3D-printed models was associated with improved intra- and postoperative outcomes. Specific aims were to determine the (1) types of applications and studies conducted, (2) types of 3D printing/materials used, (3) specific outcomes evaluated, (4) efficacy of 3D printing in planning for hip surgery, and (5) limitations of current research. The authors searched Medline, Embase, Cochrane Database of Systematic Reviews, CINAHL, and PubMed from inception through July 2017. Original research publications were included if the primary purpose was to evaluate 3D-printed models' ability to assist with the planning of hip surgeries. Papers were excluded if they were reviews, abstracts, and not available in English, their models were not patient-specific, or their research did not evaluate surgery of the acetabulofemoral joint or pelvis. Of the 3,369 unique papers identified, 21 met inclusion criteria after full-text review. Among the included studies, six evaluated 3D printing in THA, seven in PAO/PFO, and eight in fracture repairs/reconstruction. The research included nine case reports, three case series, one retrospective uncontrolled study, six prospective uncontrolled studies, and two prospective controlled studies. 3D printed models resulted in: reduced intraoperative improvisation, operating room time, blood loss/transfusions, improved positioning of plates/screws/implants, clinical scores, measures of realignment, and functional status. Recent innovations in 3D printing are promising but unproven to improve clinical outcomes in hip surgeries due to limitations of published research. This may impact utilization and reimbursement of 3D-printed models in hip surgery. Studies of resource utilization, cost-effectiveness, and controlled trials with standardized methods and clinical outcomes of relevance are needed.

First Clinical Experience with a Carbon Fibre Reinforced PEEK Composite Plating System for Anterior Cervical Discectomy and Fusion.

Carbon fibre reinforced polyether ether ketone (CFR-PEEK) is a suitable material to replace metal implants in orthopaedic surgery. The radiolucency of CFR-PEEK allows an optimal visualisation of the bone and soft tissue structures. We aimed to assess the performance and radiological and clinical outcomes of anterior cervical discectomy and fusion (ACDF) with CFR-PEEK anterior cervical plating (ACP) under first use clinical conditions. We retrospectively studied the prospectively-collected data of 42 patients who underwent ACDF with CFR-PEEK ACP between 2011 and 2016. We assessed clinical outcome (Odom’s criteria, complications) and radiological parameters (global and segmental cervical lordosis, Bridwell score for fusion, adjacent segment degeneration) preoperatively, immediately post-operatively, and after a 12-month follow-up period. Patients’ satisfaction was excellent, good, fair, and poor in 12, 19, 3, and 1 patients, respectively. Two patients developed dysphagia. No hardware failure occurred. Compared with preoperative radiographs, we observed a gain of global cervical lordosis and segmental lordosis (7.4 ± 10.1 and 5.6 ± 7.1 degrees, respectively) at the 12-month follow-up. Bridwell IF grades I, II, and III were observed in 22, 6, and 7 patients, respectively. The 12-month adjacent segment degeneration-free and adjacent segment disease-free survival rates were 93.1% and 96.3%, respectively. We observed a dysphagia rate of 5.7% and a reoperation rate of 4.8%. In conclusion, CFR-PEEK ACP shows positive outcomes in terms of implant safety, restoration of cervical lordosis, and functional recovery, and is suitable for ACDF.

Policy and Ethical Considerations for Widespread Utilization of Generic Orthopedic Implants.

In 2015, the United States spent $3.2 trillion on healthcare, representing 18% of the nation’s gross domestic product [1]. As prices continue to climb, physicians, healthcare policymakers, and industry leaders alike have sought varied means to lower costs while maintaining the quality of care. Coverage expansion, shifts toward bundled care payments, and the implementation of Medicare Payment Reform (Medicare Access and Children’s Health Insurance Program Reauthorization Act of 2015 [MACRA]) are indicative of shifting dynamics in the American healthcare system prioritizing outcomes, value, and cost-containment over the fee-for-service model [2], [3]. Orthopedic implant expenditures are considerable in the overall cost of care for surgical patients. The cost of total joint arthroplasty implants between 1996 and 2006 increased an estimated 130%. Implant and medical device costs comprise up to 60% of hospital reimbursements for primary procedures [4]. Most implants are proprietary in nature and vary substantially in their price and features depending on the industry manufacturer [5], [6], [7]. Control of implant costs is thus a necessary focus for cost containment in orthopedic surgery. To that end, as patents on many brand name implants begin to expire, “generic” implants present a unique opportunity to improve the value of orthopedic care. Although generic drugs have been used for decades in the pharmaceutical industry, the use of generic implants has only recently been considered in the field of orthopedic surgery [8], [9], [10]. In the pharmaceutical sector, an estimated $33 billion has been saved by Medicare in the United States through utilization of generic medications [11]. There could be potential for an analogous substantial reduction in healthcare expenditures via the use of generic orthopedic implants. There is some literature describing the favorable economic possibilities for use of generic orthopedic implants [9], [10], [12]. However, the ethical issues, policy implications, and potential unanticipated consequences of such a paradigm shift have not been investigated. This article discusses the pros and cons of generic implant usage from economic, clinical, and ethical perspectives.

Segmental induction heating of orthopaedic metal implants.

ObjectivesProsthetic joint infection (PJI) is a devastating complication following total joint arthroplasty. Non-contact induction heating of metal implants is a new and emerging treatment for PJI. However, there may be concerns for potential tissue necrosis. It is thought that segmental induction heating can be used to control the thermal dose and to limit collateral thermal injury to the bone and surrounding tissues. The purpose of this study was to determine the thermal dose, for commonly used metal implants in orthopaedic surgery, at various distances from the heating centre (HC).MethodsCommonly used metal orthopaedic implants (hip stem, intramedullary nail, and locking compression plate (LCP)) were heated segmentally using an induction heater. The thermal dose was expressed in cumulative equivalent minutes at 43°C (CEM43) and measured with a thermal camera at several different distances from the HC. A value of 16 CEM43 was used as the threshold for thermal damage in bone.ResultsDespite high thermal doses at the HC (7161 CEM43 to 66 640 CEM43), the thermal dose at various distances from the HC was lower than 16 CEM43 for the hip stem and nail. For the fracture plate without corresponding metal screws, doses higher than 16 CEM43 were measured up to 5 mm from the HC.ConclusionSegmental induction heating concentrates the thermal dose at the targeted metal implant areas and minimizes collateral thermal injury by using the non-heated metal as a heat sink. Implant type and geometry are important factors to consider, as they influence dissipation of heat and associated collateral thermal injury.Cite this article: B. G. Pijls, I. M. J. G. Sanders, E. J. Kuijper, R. G. H. H. Nelissen. Segmental induction heating of orthopaedic metal implants. Bone Joint Res 2018;7:609–619. DOI: 10.1302/2046-3758.711.BJR-2018-0080.R1.

Smart implants in orthopedic surgery, improving patient outcomes: a review.

Smart implants are implantable devices that provide not only therapeutic benefits but also have diagnostic capabilities. The integration of smart implants into daily clinical practice has the potential for massive cost savings to the health care system. Applications for smart orthopedic implants have been identified for knee arthroplasty, hip arthroplasty, spine fusion, fracture fixation and others. To date, smart orthopedic implants have been used to measure physical parameters from inside the body, including pressure, force, strain, displacement, proximity and temperature. The measurement of physical stimuli is achieved through integration of application-specific technology with the implant. Data from smart implants have led to refinements in implant design, surgical technique and strategies for postoperative care and rehabilitation. In spite of decades of research, with very few exceptions, smart implants have not yet become a part of daily clinical practice. This is largely because integration of current sensor technology necessitates significant modification to the implants. While the technology underlying smart implants has matured significantly over the last several decades, there are still significant technical challenges that need to be overcome before smart implants become part of mainstream health care. Sensors for next-generation smart implants will be small, simple, robust and inexpensive and will necessitate little to no modification to existing implant designs. With rapidly advancing technology, the widespread implementation of smart implants is near. New sensor technology that minimizes modifications to existing implants is the key to enabling smart implants into daily clinical practice.

Vancomycin Functionalized Nanoparticles for Bactericidal Biomaterial Surfaces.

In this paper, we describe a simple and powerful way to synthesize antibacterial biomaterials with applications as implants in orthopedic surgery. Such implants are obtained by covalently grafting onto the Ti90A16 V4 alloy surface with vancomycin-functionalized nanoparticles. Nanoparticles were produced by ring-opening metathesis polymerization of α-norbornenyl-ω-vancomycin poly(ethylene oxide) macromonomers. Vancomycin is an interesting candidate because of its use in the field of implant associated infection as it is a glycopeptide which acts on bacterial walls. As a consequence, vancomycin does not need to be released for it to be active. In the first part of this paper, the synthesis and the complete characterization of these materials are described. In a second part, the in vitro antibacterial behavior is analyzed and discussed.