33 results on '"Implant integration"'
Search Results
2. A New Augmentation Method for Improved Screw Fixation in Fragile Bone
- Author
-
Deepak Bushan Raina, Vetra Markevičiūtė, Mindaugas Stravinskas, Joeri Kok, Ida Jacobson, Yang Liu, Erdem Aras Sezgin, Hanna Isaksson, Stefan Zwingenberger, Magnus Tägil, Šarūnas Tarasevičius, and Lars Lidgren
- Subjects
biomaterial ,osteoporosis ,hip fracture ,implant integration ,implant augmentation ,Biotechnology ,TP248.13-248.65 - Abstract
Pertrochanteric fractures (TF) due to osteoporosis constitute nearly half of all proximal femur fractures. TFs are treated with a surgical approach and fracture fixation is achieved using metallic fixation devices. Poor quality cancellous bone in osteoporotic patients makes anchorage of a fixation device challenging, which can lead to failure of the fracture fixation. Methods to reinforce the bone-implant interface using bone cement (PMMA) and other calcium phosphate cements in TFs have been described earlier but a clear evidence on the advantage of using such biomaterials for augmentation is weak. Furthermore, there is no standardized technique for delivering these biomaterials at the bone-implant interface. In this study, we firstly describe a method to deliver a calcium sulphate/hydroxyapatite (CaS/HA) based biomaterial for the augmentation of a lag-screw commonly used for TF fixation. We then used an osteoporotic Sawbones model to study the consequence of CaS/HA augmentation on the immediate mechanical anchorage of the lag-screw to osteoporotic bone. Finally, as a proof-of-concept, the method of delivering the CaS/HA biomaterial at the bone-implant interface as well as spreading of the CaS/HA material at this interface was tested in patients undergoing treatment for TF as well as in donated femoral heads. The mechanical testing results indicated that the CaS/HA based biomaterial increased the peak extraction force of the lag-screw by 4 times compared with un-augmented lag-screws and the results were at par with PMMA. The X-ray images from the patient series showed that it was possible to inject the CaS/HA material at the bone-implant interface without applying additional pressure and the CaS/HA material spreading was observed at the interface of the lag-screw threads and the bone. Finally, the spreading of the CaS/HA material was also verified on donated femoral heads and micro-CT imaging indicated that the entire length of the lag-screw threads was covered with the CaS/HA biomaterial. In conclusion, we present a novel method for augmenting a lag-screw in TFs, which could potentially reduce the risk of fracture fixation failure and reoperation in fragile osteoporotic patients.
- Published
- 2022
- Full Text
- View/download PDF
3. Effect of Oxidative Stress on Bone Remodeling in Periprosthetic Osteolysis.
- Author
-
Galliera, Emanuela, Massaccesi, Luca, Banfi, Giuseppe, De Vecchi, Elena, Ragone, Vincenza, and Corsi Romanelli, Massimiliano M.
- Subjects
- *
BONE remodeling , *OXIDATIVE stress , *OSTEOCLASTOGENESIS , *REACTIVE oxygen species , *THERAPEUTICS , *INFLAMMATION , *FRACTURE healing , *BONE resorption - Abstract
The success of implant performance and arthroplasty is based on several factors, including oxidative stress-induced osteolysis. Oxidative stress is a key factor of the inflammatory response. Implant biomaterials can release wear particles which may elicit adverse reactions in patients, such as local inflammatory response leading to tissue damage, which eventually results in loosening of the implant. Wear debris undergo phagocytosis by macrophages, inducing a low-grade chronic inflammation and reactive oxygen species (ROS) production. In addition, ROS can also be directly produced by prosthetic biomaterial oxidation. Overall, ROS amplify the inflammatory response and stimulate both RANKL-induced osteoclastogenesis and osteoblast apoptosis, resulting in bone resorption, leading to periprosthetic osteolysis. Therefore, a growing understanding of the mechanism of oxidative stress-induced periprosthetic osteolysis and anti-oxidant strategies of implant design as well as the addition of anti-oxidant agents will help to improve implants' performances and therapeutic approaches. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
- View/download PDF
4. Sequential drug delivery to modulate macrophage behavior and enhance implant integration.
- Author
-
O'Brien, Erin M., Risser, Gregory E., and Spiller, Kara L.
- Subjects
- *
DRUG delivery systems , *MACROPHAGE activation , *SYSTEMS design , *HEALING - Abstract
Macrophages are major upstream regulators of the inflammatory response to implanted biomaterials. Sequential functions of distinct macrophage phenotypes are essential to the normal tissue repair process, which ideally results in vascularization and integration of implants. Improper timing of M1 or M2 macrophage activation results in dysfunctional healing in the form of chronic inflammation or fibrous encapsulation of the implant. Thus, biphasic drug delivery systems that modulate macrophage behavior are an appealing approach to promoting implant integration. In this review, we describe the timing and roles of macrophage phenotypes in healing, then highlight current drug delivery systems designed to sequentially modulate macrophage behavior. Unlabelled Image [ABSTRACT FROM AUTHOR]
- Published
- 2019
- Full Text
- View/download PDF
5. MRI Findings at the Bone-Component Interface in Symptomatic Unicompartmental Knee Arthroplasty and the Relationship to Radiographic Findings.
- Author
-
Kleeblad, Laura Jill, Zuiderbaan, Hendrik A., Burge, Alissa J., Amirtharaj, Mark J., Potter, Hollis G., and Pearle, Andrew D.
- Abstract
Background: The most common modes of failure of cemented unicompartmental knee arthroplasty (UKA) designs are aseptic loosening and unexplained pain at short- to mid-term follow-up, which is likely linked to early fixation failure. Determining these modes of failure remains challenging; conventional radiographs are limited for use in assessing radiolucent lines, with only fair sensitivity and specificity for aseptic loosening.Questions/Purposes: We sought to characterize the bone-component interface of patients with symptomatic cemented medial unicompartmental knee arthroplasty (UKA) using magnetic resonance imaging (MRI) and to determine the relationship between MRI and conventional radiographic findings.Methods: This retrospective observational study included 55 consecutive patients with symptomatic cemented UKA. All underwent MRI with addition of multiacquisition variable-resonance image combination (MAVRIC) at an average of 17.8 ± 13.9 months after surgery. MRI studies were reviewed by two independent musculoskeletal radiologists. MRI findings at the bone-cement interface were quantified, including bone marrow edema, fibrous membrane, osteolysis, and loosening. Radiographs were reviewed for existence of radiolucent lines. Inter-rater agreement was determined using Cohen’s κ statistic.Results: The vast majority of symptomatic UKA patients demonstrated bone marrow edema pattern (71% and 75%, respectively) and fibrous membrane (69% and 89%, respectively) at the femoral and tibial interface. Excellent and substantial inter-rater agreement was found for the femoral and tibial interface, respectively. Furthermore, MRI findings and radiolucent lines observed on conventional radiographs were poorly correlated.Conclusion: MRI with the addition of MAVRIC sequences could be a complementary tool for assessing symptomatic UKA and for quantifying appearances at the bone-component interface. This technique showed good reproducibility of analysis of the bone-component interface after cemented UKA. Future studies are necessary to define the bone-component interface of symptomatic and asymptomatic UKA patients. [ABSTRACT FROM AUTHOR]
- Published
- 2018
- Full Text
- View/download PDF
6. TNF-α-Inhibition Improves the Biocompatibility of Porous Polyethylene Implants In Vivo
- Author
-
Hussain, Timon, Gellrich, Donata, Siemer, Svenja, Reichel, Christoph A., Eckrich, Jonas, Dietrich, Dimo, Knauer, Shirley K., Stauber, Roland H., and Strieth, Sebastian
- Published
- 2021
- Full Text
- View/download PDF
7. Effect of Oxidative Stress on Bone Remodeling in Periprosthetic Osteolysis
- Author
-
Giuseppe Banfi, Elena De Vecchi, Emanuela Galliera, Massimiliano Marco Corsi Romanelli, Luca Massaccesi, Vincenza Ragone, Galliera, E, Massaccesi, L, Banfi, G, De Vecchi, E, Ragone, V, and Romanelli, Mmc
- Subjects
chemistry.chemical_classification ,Reactive oxygen species ,Osteolysis ,business.industry ,Endocrinology, Diabetes and Metabolism ,Inflammatory response ,Osteoblast ,Inflammation ,medicine.disease ,medicine.disease_cause ,Bone resorption ,Implant integration ,Bone remodeling ,Endocrinology ,medicine.anatomical_structure ,chemistry ,Oxidative stress ,medicine ,Cancer research ,Periprosthetic osteolysis ,Orthopedics and Sports Medicine ,Implant ,medicine.symptom ,business - Abstract
The success of implant performance and arthroplasty is based on several factors, including oxidative stress-induced osteolysis. Oxidative stress is a key factor of the inflammatory response. Implant biomaterials can release wear particles which may elicit adverse reactions in patients, such as local inflammatory response leading to tissue damage, which eventually results in loosening of the implant. Wear debris undergo phagocytosis by macrophages, inducing a low-grade chronic inflammation and reactive oxygen species (ROS) production. In addition, ROS can also be directly produced by prosthetic biomaterial oxidation. Overall, ROS amplify the inflammatory response and stimulate both RANKL-induced osteoclastogenesis and osteoblast apoptosis, resulting in bone resorption, leading to periprosthetic osteolysis. Therefore, a growing understanding of the mechanism of oxidative stress-induced periprosthetic osteolysis and anti-oxidant strategies of implant design as well as the addition of anti-oxidant agents will help to improve implants’ performances and therapeutic approaches.
- Published
- 2021
8. Improved bioactivity of GUMMETAL®, Ti59Nb36Ta2Zr3O0.3, via formation of nanostructured surfaces.
- Author
-
Kamini Divakarla, Shiva, Seiji Yamaguchi, Tadashi Kokubo, Dong-Wook Han, Jae Ho Lee, and Chrzanowski, Wojciech
- Abstract
The leading reason for implant revision surgery globally is lack of implant integration with surrounding bone. A new titanium alloy GUMMETAL® (Ti59Nb36Ta2Zr3O0.3) is currently used in biomedical devices and has a Young’s modulus that is better matched to bone. The surface was subject to NaOH, CaCl2, heat and water treatment (BioGum) after which the surfaces were evaluated using atomic force microscope, scanning electron microscope, X-ray diffractometer and elemental analysis using energy dispersive X-ray. To demonstrate enhanced bone bonding ability and cytocompatibility, apatite formation in simulated body fluid and in vitro stem cell attachment, proliferation and cytoskeleton organisation were examined. The formation of a ~200 nm nanoscale needle-like calcium titanate network on the surface following treatment was revealed and upon soaking in simulated body fluid, the formation of a ~5µm layer of apatite. Metabolic activity of rat bone marrow stem cells on BioGum was increased in comparison to control and the cell number appeared greater, with more elongated morphology as early as 2h post-seeding. This positions the modification as a simple and potentially universal technology for the improvement of implant integration. [ABSTRACT FROM AUTHOR]
- Published
- 2018
- Full Text
- View/download PDF
9. TNF-α-Inhibition Improves the Biocompatibility of Porous Polyethylene Implants In Vivo
- Author
-
Donata Gellrich, Dimo Dietrich, Christoph A. Reichel, Shirley K. Knauer, Jonas Eckrich, Timon Hussain, Sebastian Strieth, Roland H. Stauber, and Svenja Siemer
- Subjects
Male ,Biocompatibility ,Angiogenesis ,0206 medical engineering ,Medizin ,Biomedical Engineering ,Medicine (miscellaneous) ,Biocompatible Materials ,02 engineering and technology ,Etanercept ,03 medical and health sciences ,Mice ,0302 clinical medicine ,Tissue engineering ,In vivo ,medicine ,Animals ,Fluorescence microscopy ,Matrigel ,ECM ,Chemistry ,Tumor Necrosis Factor-alpha ,Prostheses and Implants ,020601 biomedical engineering ,Implant integration ,Mice, Inbred C57BL ,Polyethylene ,030220 oncology & carcinogenesis ,Tumor necrosis factor alpha ,Original Article ,Porous polyethylene ,Implant ,Biologie ,Porosity ,Biomedical engineering ,medicine.drug - Abstract
Background: To improve the biocompatibility of porous polyethylene (PPE) implants and expand their application range for reconstructive surgery in poorly vascularized environments, implants were coated with tumor necrosis factor α (TNFα) inhibitor Etanercept. While approved for systemic application, local application of the drug is a novel experimental approach. Microvascular and mechanical integration as well as parameters of inflammation were analyzed in vivo. Methods: PPE implants were coated with Etanercept and extracellular matrix (ECM) components prior to implantation into dorsal skinfold chambers of C57BL/6 mice. Fluorescence microscopy analyses of angiogenesis and local inflammatory response were thrice performed in vivo over a period of 14 days to assess tissue integration and biocompatibility. Uncoated implants and ECM-coated implants served as controls. Results: TNFα inhibition with Etanercept led to a reduced local inflammatory response: leukocyte-endothelial cell adherence was significantly lowered compared to both control groups (n = 6/group) on days 3 and 14, where the lowest values were reached: 3573.88 leukocytes/mm-2 ± 880.16 (uncoated implants) vs. 3939.09 mm-2 ± 623.34 (Matrigel only) vs. 637.98 mm-2 + 176.85 (Matrigel and Etanercept). Implant-coating with Matrigel alone and Matrigel and Etanercept led to significantly higher vessel densities 7 and 14 days vs. 3 days after implantation and compared to uncoated implants. Mechanical implant integration as measured by dynamic breaking strength did not differ after 14 days. Conclusion: Our data show a reduced local inflammatory response to PPE implants after immunomodulatory coating with Etanercept in vivo, suggesting improved biocompatibility. Application of this tissue engineering approach is therefore warranted in models of a compromised host environment.
- Published
- 2021
10. A new augmentation method for improved screw fixation in fragile bone
- Author
-
Raina, Deepak Bushan, Stravinskas, Mindaugas, Markevičiūtė, Vetra, Kok, Joeri, Jacobson, Ida, Liu, Yang, Sezgin, Erdem Aras, Isaksson, Hanna, Zwingenberger, Stefan, Tägil, Magnus, Tarasevičius, Šarūnas, Lidgren, Lars, and Tıp Fakültesi
- Subjects
Hip Fracture ,Implant Integration ,Osteoporosis ,Biomaterial ,Implant Augmentation - Abstract
Pertrochanteric fractures (TF) due to osteoporosis constitute nearly half of all proximal femur fractures. TFs are treated with a surgical approach and fracture fixation is achieved using metallic fixation devices. Poor quality cancellous bone in osteoporotic patients makes anchorage of a fixation device challenging, which can lead to failure of the fracture fixation. Methods to reinforce the bone-implant interface using bone cement (PMMA) and other calcium phosphate cements in TFs have been described earlier but a clear evidence on the advantage of using such biomaterials for augmentation is weak. Furthermore, there is no standardized technique for delivering these biomaterials at the bone-implant interface. In this study, we firstly describe a method to deliver a calcium sulphate/hydroxyapatite (CaS/HA) based biomaterial for the augmentation of a lag-screw commonly used for TF fixation. We then used an osteoporotic Sawbones model to study the consequence of CaS/HA augmentation on the immediate mechanical anchorage of the lag-screw to osteoporotic bone. Finally, as a proof-of-concept, the method of delivering the CaS/HA biomaterial at the bone-implant interface as well as spreading of the CaS/HA material at this interface was tested in patients undergoing treatment for TF as well as in donated femoral heads. The mechanical testing results indicated that the CaS/HA based biomaterial increased the peak extraction force of the lag-screw by 4 times compared with un-augmented lag-screws and the results were at par with PMMA. The X-ray images from the patient series showed that it was possible to inject the CaS/HA material at the bone-implant interface without applying additional pressure and the CaS/HA material spreading was observed at the interface of the lag-screw threads and the bone. Finally, the spreading of the CaS/HA material was also verified on donated femoral heads and micro-CT imaging indicated that the entire length of the lag-screw threads was covered with the CaS/HA biomaterial. In conclusion, we present a novel method for augmenting a lag-screw in TFs, which could potentially reduce the risk of fracture fixation failure and reoperation in fragile osteoporotic patients.
- Published
- 2022
11. Peri-implant bone adaptations to overloading in rat tibiae: experimental investigations and numerical predictions.
- Author
-
Piccinini, Marco, Cugnoni, Joel, Botsis, John, Ammann, Patrick, and Wiskott, Anselm
- Subjects
- *
TIBIA , *BONE remodeling , *LABORATORY rats , *TITANIUM , *BONE density , *ALGORITHMS - Abstract
Objectives (i) To assess the effects of mechanical overloading on implant integration in rat tibiae, and (ii) to numerically predict peri-implant bone adaptation. Materials and methods Transcutaneous titanium implants were simultaneously placed into both tibiae of rats ( n = 40). After 2 weeks of integration, the implants of the right tibiae were stimulated daily for 4 weeks with loads up to 5N (corresponding to peak equivalent strains of 3300 ± 500 με). The effects of stimulation were assessed by ex vivo mechanical tests and quantification of bone mineral density ( BMD) in selected regions of interests ( ROIs). Specimen-specific finite element models were generated and processed through an iterative algorithm to mimic bone adaptation. Results Bilateral implantation provoked an unstable integration that worsened when mild (2-4N) external loads were applied. In contrast, a stimulation at 5N tended to 'counterbalance' the harmful effects of daily activity and, if applied to well-integrated specimens, significantly augmented the implants' resistance to failure (force: +73% P < 0.01, displacement: +50% P < 0.01 and energy: +153% P < 0.01). Specimen-specific numerical predictions were in close agreement with the experimental findings. Both local and overall BMD variations, as well as the implants' lateral stability, were predicted with small errors (0.14 gHA/cm3 and 0.64%, respectively). Conclusions The rats' daily activity detrimentally affects implant integration. Conversely, external stimulations of large magnitudes counterbalance this effect and definitively improve integration. These changes can be predicted using the proposed numerical approach. [ABSTRACT FROM AUTHOR]
- Published
- 2016
- Full Text
- View/download PDF
12. Bone structure characterisation using neutron scattering techniques
- Abstract
Bones have unique mechanical properties that originate from their main constituents: mineral, in the form of hydroxyapatite (HAp) crystals, and collagen type-I. The stiffness of the HAp mineral combined with the flexibility of collagen, and their intricate hierarchical arrangement from the smallest individual building blocks to the organ level, result in a composite tissue with a remarkable ability to withstand complex loading scenarios. The mechanisms behind this fracture resistance are not fully understood, and further insights are necessary to better comprehend the complex interplay between the constituents of bone and their multiscale structural organisation. With such knowledge, improved treatments for injuries and diseases could be developed. X-ray based techniques have long been state-of-the-art when studying bone tissue. This is due to the strong interaction between x-rays and the heavier elements in the mineral compared to lighter elements in the surrounding tissue. However, this strong interaction overshadows the information from the collagen phase. Neutrons interact differently with matter than x-rays and exhibit an especially strong interaction with hydrogen. As hydrogen is abundant in the organic phase in bone, neutron techniques lend themselves as alternatives or complements to their x-ray counterparts for focusing on the collagen rather than the mineral phase. The work presented in this thesis explores the potential of neutron scattering techniques in bone research and elucidates the complementary nature of neutron and x-ray scattering techniques toward the structural characterisation of bone tissue, both on the nano- and microscale. Central to the work are dual modality, i.e., neutron and x-ray, small-angle scattering (SAS) and tomography measurements on the same specimens, allowing comparisons between the two probes. The first two studies in this thesis employed SAS to study the mineralisation process of newly formed bone, and to elucidate the possi
- Published
- 2021
13. Systematic Review on Characteristics and Reporting Quality of Animal Studies in Liver Regeneration Triggered by Portal Vein Occlusion and Associating Liver Partition and Portal Vein Ligation for Staged Hepatectomy: Adherence to the ARRIVE Guidelines
- Author
-
Zoltan Czigany, Dora Krisztina Tihanyi, Ulf P. Neumann, Rene Tolba, Attila Szijártó, Georg Lurje, Bernd Denecke, and András Fülöp
- Subjects
Animal Experimentation ,Research Report ,medicine.medical_specialty ,CARCINOMA ,Reporting quality ,medicine.medical_treatment ,media_common.quotation_subject ,MODELS ,Portal vein occlusion ,Subgroup analysis ,Portal vein ligation ,03 medical and health sciences ,0302 clinical medicine ,Occlusion ,medicine ,Animals ,Hepatectomy ,Quality (business) ,Ligation ,media_common ,IMPLANT INTEGRATION ,Portal Vein ,business.industry ,ARRIVE guidelines ,EMBOLIZATION ,Checklist ,Liver regeneration ,Liver Regeneration ,030220 oncology & carcinogenesis ,Emergency medicine ,030211 gastroenterology & hepatology ,Surgery ,ALPPS ,Animal studies ,business ,Liver tumors - Abstract
Background: Portal vein occlusion and associating liver partition and portal vein ligation for staged hepatectomy techniques are in the spotlight of oncological liver surgery. Research involving animal models is indispensable to study the mechanisms of liver regeneration. Inaccurate reporting acts as a significant barrier during the correct interpretation of preclinical findings. Hence, we performed a systematic review to evaluate the status quo of the reporting standards and to assess the potential factors influencing reporting in animal studies, which are focusing on portal vein occlusion and/or associating liver partition and portal vein ligation for staged hepatectomy techniques. Materials and methods: A systematic review was performed in the PubMed and Ovid MEDLINE databases. Baseline study characteristics were recorded, and quality assessment was performed using the Animals in Research: Reporting in vivo Experiments (ARRIVE) checklist. Results: A total of 107 research articles were included for the comprehensive assessment. In the subgroup analysis, newer reports and studies from the post-ARRIVE era, and reports from Europe were all associated with significantly higher ARRIVE scores (P
- Published
- 2019
14. Systematic Review on Characteristics and Reporting Quality of Animal Studies in Liver Regeneration Triggered by Portal Vein Occlusion and Associating Liver Partition and Portal Vein Ligation for Staged Hepatectomy
- Subjects
CARCINOMA ,Reporting quality ,IMPLANT INTEGRATION ,ARRIVE guidelines ,MODELS ,Portal vein occlusion ,Liver regeneration ,ALPPS ,EMBOLIZATION ,Liver tumors - Abstract
Background: Portal vein occlusion and associating liver partition and portal vein ligation for staged hepatectomy techniques are in the spotlight of oncological liver surgery. Research involving animal models is indispensable to study the mechanisms of liver regeneration. Inaccurate reporting acts as a significant barrier during the correct interpretation of preclinical findings. Hence, we performed a systematic review to evaluate the status quo of the reporting standards and to assess the potential factors influencing reporting in animal studies, which are focusing on portal vein occlusion and/or associating liver partition and portal vein ligation for staged hepatectomy techniques.Materials and methods: A systematic review was performed in the PubMed and Ovid MEDLINE databases. Baseline study characteristics were recorded, and quality assessment was performed using the Animals in Research: Reporting in vivo Experiments (ARRIVE) checklist.Results: A total of 107 research articles were included for the comprehensive assessment. In the subgroup analysis, newer reports and studies from the post-ARRIVE era, and reports from Europe were all associated with significantly higher ARRIVE scores (P Conclusions: Although an improving trend has been observed in reporting quality over the past years, this effect was clearly insufficient. Our results emphasize the need for further measures to improve the methodical quality at all levels of planning, execution, and reporting of preclinical studies in liver regeneration research. (C) 2018 Elsevier Inc. All rights reserved.
- Published
- 2019
15. Bone structure characterisation using neutron scattering techniques
- Author
-
Törnquist, Elin
- Subjects
x-ray tomography ,small-angle x-ray scattering (SAXS) ,Experimental mechanics ,neutron tomography ,small-angle neutron scattering (SANS) ,Medical Engineering ,microscale ,nanoscale ,implant integration ,tomography ,mechanical properties ,biomechanics - Abstract
Bones have unique mechanical properties that originate from their main constituents: mineral, in the form of hydroxyapatite (HAp) crystals, and collagen type-I. The stiffness of the HAp mineral combined with the flexibility of collagen, and their intricate hierarchical arrangement from the smallest individual building blocks to the organ level, result in a composite tissue with a remarkable ability to withstand complex loading scenarios. The mechanisms behind this fracture resistance are not fully understood, and further insights are necessary to better comprehend the complex interplay between the constituents of bone and their multiscale structural organisation. With such knowledge, improved treatments for injuries and diseases could be developed. X-ray based techniques have long been state-of-the-art when studying bone tissue. This is due to the strong interaction between x-rays and the heavier elements in the mineral compared to lighter elements in the surrounding tissue. However, this strong interaction overshadows the information from the collagen phase. Neutrons interact differently with matter than x-rays and exhibit an especially strong interaction with hydrogen. As hydrogen is abundant in the organic phase in bone, neutron techniques lend themselves as alternatives or complements to their x-ray counterparts for focusing on the collagen rather than the mineral phase. The work presented in this thesis explores the potential of neutron scattering techniques in bone research and elucidates the complementary nature of neutron and x-ray scattering techniques toward the structural characterisation of bone tissue, both on the nano- and microscale. Central to the work are dual modality, i.e., neutron and x-ray, small-angle scattering (SAS) and tomography measurements on the same specimens, allowing comparisons between the two probes. The first two studies in this thesis employed SAS to study the mineralisation process of newly formed bone, and to elucidate the possibility of gaining additional information about bone nanostructure by using neutrons. Small-angle x-ray scattering (SAXS) data from cortical bone taken from rabbits at different stages of maturation (from newborn to 6 months of age) showed an increase in thickness and orientational homogeneity of the mineral particles as the tissue matured. Comparison of the SAXS results with techanical data from the same cohort of specimens suggested that changes in mechanical properties are explained by the amount of mineral in the tissue as well as by the dimensions of the mineral particles. Small-angle neutron scattering (SANS) and SAXS were then used to examine the nanostructure of cortical bone from larger animals of different species (cow, pig, and sheep). Comparison of the collected data showcased how neutrons and x-rays scatter in a very similar way when interacting with the bone nanostructure, suggesting that bone can be considered as a two-component composite material at the investigated length scale. The final two studies presented in this thesis focused on the complementarity of neutron and x-ray tomography (NT and XRT) on the microscale, and on the influence of hydration on NT image quality and the mechanical properties of bone. In the first tomographic study, rat tibiae with metallic implants were imaged with both NT and XRT. Using a dual modality image registration algorithm, the image data were compared in terms of visualised structures and the quality of the visualisation. The differences in how neutrons and x-rays interact with skeletal tissues and metallic implants were highlighted. Furthermore, the benefits of using both modalities in combination, to benefit from their complementary strengths, was demonstrated. Possible improvement of the visualisation of internal structures using NT, by regulating the hydration type (H2O or D2O) and quantity in the specimens, was then addressed. Rat tibiae and trabecular bovine bone plugs were imaged at different states of hydration (hydrated, dry, and rehydrated in D2O after drying) to investigate the effects on the visualisation of structures in the NT images. The imaging was combined with mechanical testing of the bone plugs to assess the changes in mechanical properties associated with drying. The trabecular bone plugs showed that drying reduced contrast between bone and soft tissues. However, no negative effects on the mechanical properties for the chosen duration of drying were found. Imaging of the rat tibiae indicated that the contrast between bone and air was high in the dried state but decreased with increasing rehydration. When free D2O was present in the medullary canal, trabecular structures could not be resolved. In summary, the work presented in this thesis has demonstrated bone tissue to be a two-component composite material at the nanoscale, with the inorganic mineral phase affecting the tissue’s mechanical properties through both the quantity and size of the mineral particles. Furthermore, the potential of NT for gaining novel insights about bone on the tissue scale is demonstrated, which paves the way for future neutron applications within the field of musculoskeletal tissue biomechanics. Due to the hydrogen sensitivity, NT can be used to identify the distribution and amount of soft skeletal tissues within a specimen, which could yield greater information about how soft skeletal tissues change, e.g., with age or due to different medical treatments. However, further investigation regarding the state of hydration is needed to optimise the visualisation of structures in the NT images.
- Published
- 2021
16. Influence of gait loads on implant integration in rat tibiae: Experimental and numerical analysis.
- Author
-
Piccinini, Marco, Cugnoni, Joel, Botsis, John, Ammann, Patrick, and Wiskott, Anselm
- Subjects
- *
GAIT in humans , *MECHANICAL loads , *TREATMENT of fractures , *BONE diseases , *DRUG delivery systems , *LABORATORY rats - Abstract
Implanted rat bones play a key role in studies involving fracture healing, bone diseases or drugs delivery among other themes. In most of these studies the implants integration also depends on the animal daily activity and musculoskeletal loads, which affect the implants mechanical environment. However, the tissue adaption to the physiological loads is often filtered through control groups or not inspected. This work aims to investigate experimentally and numerically the effects of the daily activity on the integration of implants inserted in the rat tibia, and to establish a physiological loading condition to analyse the peri-implant bone stresses during gait. Two titanium implants, single and double cortex crossing, are inserted in the rat tibia. The animals are caged under standard conditions and divided in three groups undergoing progressive integration periods. The results highlight a time-dependent increase of bone samples with significant cortical bone loss. The phenomenon is analysed through specimen-specific Finite Element models involving purpose-built musculoskeletal loads. Different boundary conditions replicating the post-surgery bone-implant interaction are adopted. The effects of the gait loads on the implants integration are quantified and agree w ith the results of the experiments. The observed cortical bone loss can be considered as a transient state of integration due to bone disuse atrophy, initially triggered by a loss of bone-implant adhesion and subsequently by a cyclic opening of the interface. [ABSTRACT FROM AUTHOR]
- Published
- 2014
- Full Text
- View/download PDF
17. Ultrasound biomicroscopy (UBM) and scanning acoustic microscopy (SAM) for the assessment of hernia mesh integration: a comparison to standard histology in an experimental model.
- Author
-
Petter-Puchner, A., Gruber-Blum, S., Walder, N., Fortelny, R., Redl, H., and Raum, K.
- Subjects
- *
DIAGNOSIS of abdominal diseases , *ACOUSTIC microscopy , *HERNIA , *ACOUSTIC imaging , *ACOUSTIC holography - Abstract
Background: Mesh integration is a key parameter for reliable and safe hernia repair. So far, its assessment is based on histology obtained from rare second-look operations or experimental research. Therefore, non-invasive high-resolution imaging techniques would be of great value. Ultrasound biomicroscopy (UBM) and scanning acoustic microscopy (SAM) have shown potential in the imaging of hard and soft tissues. This experimental study compared the detection of mesh integration, foreign body reaction and scar formation in UBM/SAM with standard histology. Materials and methods: Ten titanized polypropylene meshes were implanted in rats in a model of onlay repair. 17 days postoperative animals were killed and samples were paraffin embedded for histology (H&E, Cresyl violet) or processed for postmortem UBM/SAM. The observation period was uneventful and meshes appeared well integrated. Results: Relocation of neighboring cross-sectional levels could easily be achieved with the 40-MHz UBM and granulation tissue could be distinguished from adjacent muscle tissue layers. The spatial resolution of approximately 8 μm of the 200-MHz UBM system images was comparable to standard histology (2.5-5× magnification) and allowed a clear identification of mesh fibers and different tissue types, e.g., scar, fat, granulation, and muscle tissues, as well as vessels, abscedations, and foreign body giant cell clusters. Conclusion: This pilot study demonstrates the potential of high-frequency ultrasound to assess hernia mesh integration non-invasively. Although the methods lack cell-specific information, tissue integration could reliably be assessed. The possibility of conducting UBM in vivo advocates this method as a guidance tool for the indication of second-look operations and subsequent elaborate histological analyses. [ABSTRACT FROM AUTHOR]
- Published
- 2014
- Full Text
- View/download PDF
18. Does PRP enhance bone integration with grafts, graft substitutes, or implants? A systematic review.
- Author
-
Roffi, Alice, Filardo, Giuseppe, Kon, Elizaveta, and Marcacci, Maurilio
- Subjects
- *
PLATELET-rich plasma , *ORTHOPEDIC implants , *BIOMATERIALS , *EXTRACELLULAR matrix proteins , *REGENERATION (Biology) , *ARTIFICIAL implants - Abstract
Background Several bone implants are applied in clinical practice, but none meets the requirements of an ideal implant. Platelet-rich plasma (PRP) is an easy and inexpensive way to obtain growth factors in physiologic proportions that might favour the regenerative process. The aim of this review is to analyse clinical studies in order to investigate the role of PRP in favouring bone integration of graft, graft substitutes, or implants, and to identify the materials for which the additional use of PRP might be associated with superior osseo- and soft tissues integration. Methods A search on PubMed database was performed considering the literature from 2000 to 2012, using the following string: ("Bone Substitutes"[Mesh] OR "Bone Transplantation"[Mesh] OR "Bone Regeneration"[Mesh] OR "Osseointegration"[Mesh]) AND ("Blood Platelets"[Mesh] OR "Platelet-Rich Plasma"[Mesh]). After abstracts screening, the full-texts of selected papers were analyzed and the papers found from the reference lists were also considered. The search focused on clinical applications documented in studies in the English language: levels of evidence included in the literature analysis were I, II and III. Results Literature analysis showed 83 papers that fulfilled the inclusion criteria: 26 randomized controlled trials (RCT), 14 comparative studies, 29 case series, and 14 case reports. Several implant materials were identified: 24 papers on autologous bone, 6 on freeze-dried bone allograft (FDBA), 16 on bovine porous bone mineral (BPBM), 9 on β-tricalcium phosphate (β-TCP), 4 on hydroxyapatite (HA), 2 on titanium (Ti), 1 on natural coral, 1 on collagen sponge, 1 on medical-grade calcium sulphate hemihydrate (MGCSH), 1 on bioactive glass (BG) and 18 on a combination of biomaterials. Only 4 papers were related to the orthopaedic field, whereas the majority belonged to clinical applications in oral/maxillofacial surgery. Conclusions The systematic research showed a growing interest in this approach for bone implant integration, with an increasing number of studies published over time. However, knowledge on this topic is still preliminary, with the presence mainly of low quality studies. Many aspects still have to be understood, such as the biomaterials that can benefit most from PRP and the best protocol for PRP both for production and application. [ABSTRACT FROM AUTHOR]
- Published
- 2013
- Full Text
- View/download PDF
19. Bone formation in TiO2 bone scaffolds in extraction sockets of minipigs.
- Author
-
Tiainen, Hanna, Wohlfahrt, Johan Caspar, Verket, Anders, Lyngstadaas, S. Petter, and Haugen, Håvard J.
- Subjects
TITANIUM dioxide ,TISSUE scaffolds ,BONE growth ,POROUS materials ,TOMOGRAPHY ,BONE density ,LABORATORY swine - Abstract
Abstract: The osteoconductive capacity of TiO
2 scaffolds was investigated by analysing the bone ingrowth into the scaffold structure following their placement into surgically modified extraction sockets in Gottingen minipigs. Non-critical size defects were used in order to ensure sufficient bone regeneration for the evaluation of bone ingrowth to the porous scaffold structure, and sham sites were used as positive control. Microcomputed tomographic analysis revealed 73.6±11.1% of the available scaffold pore space to be occupied by newly formed bone tissue, and the volumetric bone mineral density of the regenerated bone was comparable to that of the native cortical bone. Furthermore, histological evidence of vascularization and the presence of bone lamellae surrounding some of the blood vessels were also observed within the inner regions of the scaffold, indicating that the highly interconnected pore structure of the TiO2 scaffolds supports unobstructed formation of viable bone tissue within the entire scaffold structure. In addition, bone tissue was found to be in direct contact with 50.0±21.5% of the TiO2 struts, demonstrating the good biocompatibility and osteoconductivity of the scaffold material. [Copyright &y& Elsevier]- Published
- 2012
- Full Text
- View/download PDF
20. Influence of Statins locally applied from orthopedic implants on osseous integration.
- Author
-
Pauly, Stephan, Back, David A., Kaeppler, Kathrin, Haas, Norbert P., Schmidmaier, Gerhard, and Wildemann, Britt
- Subjects
- *
STATINS (Cardiovascular agents) , *ORTHOPEDIC implants , *ORTHOPEDIC surgery , *FEMUR , *BONE morphogenetic proteins - Abstract
Background: Simvastatin increases the expression of bone morphogenetic protein 2 (BMP-2) in osteoblasts, therefore it is important to investigate the influence of statins on bone formation, fracture healing and implant integration. The aim of the present study was to investigate the effect of Simvastatin, locally applied from intramedullary coated and bioactive implants, on bone integration using biomechanical and histomorphometrical analyses. Methods: Eighty rats received retrograde nailing of the femur with titanium implants: uncoated vs. polymer-only (poly(D,L-lactide)) vs. polymer plus drug coated (either Simvastatin low- or high dosed; "SIM low/ high"). Femurs were harvested after 56 days for radiographic and histomorphometric or biomechanical analysis (push-out). Results: Radiographic analysis revealed no pathological findings for animals of the control and SIM low dose group. However, n=2/10 animals of the SIM high group showed osteolysis next to the implant without evidence of bacterial infection determined by microbiological analysis. Biomechanical results showed a significant decrease in fixation strength for SIM high coated implants vs. the control groups (uncoated and PDLLA). Histomorphometry revealed a significantly reduced total as well as direct bone/implant contact for SIM high- implants vs. controls (uncoated and PDLLA-groups). Total contact was reduced for SIM low vs. uncoated controls. Significantly reduced new bone formation was measured around SIM high coated implants vs. both control groups. Conclusions: This animal study suggests impaired implant integration with local application of Simvastatin from intramedullary titanium implants after 8 weeks when compared to uncoated or carrier-only coated controls. [ABSTRACT FROM AUTHOR]
- Published
- 2012
- Full Text
- View/download PDF
21. Biologic hernia implants in experimental intraperitoneal onlay mesh plasty repair: the impact of proprietary collagen processing methods and fibrin sealant application on tissue integration.
- Author
-
Petter-Puchner, A., Fortelny, R., Silic, K., Brand, J., Gruber-Blum, S., and Redl, H.
- Subjects
- *
FIBRIN tissue adhesive , *HERNIA surgery , *ARTIFICIAL implant complications , *FOREIGN bodies , *SPRAGUE Dawley rats - Abstract
Background: Biologic implants have been recommended for reinforcement in routine and challenging hernia repair. However, experimental and clinical studies have reported adverse effects (e.g., slow implant integration and pronounced foreign body reaction). To evaluate the impact of different material processing methods (cross-linking vs. non-cross-linking of collagen) and implant design, four different biologic hernia implants were compared directly in experimental intraperitoneal onlay mesh plasty (IPOM). Tissue integration, shrinkage, and foreign body reaction were primary outcome parameters. Methods: In this study, 48 Sprague-Dawley rats were randomized to four treatment groups. Open IPOM repair was performed. One peritoneal defect per animal was covered with 2 × 2 cm patches of cross-linked or non-cross-linked implants including CollaMend ( n = 12), Peripatch ( n = 12), Surgisis ( n = 12), and Tutomesh ( n = 12). In half of the animals, fibrin sealant was applied for additional fixation and to cover sutures. The observation period was 60 days. The primary outcome parameters were implant integration, shrinkage, and foreign body reaction. Macroscopic and histologic assessments were performed. Results: The integration of implants was insufficient in all the groups. The implants could be detached easily from the underlying tissue, and the penetration of fibroblasts and vessels was limited to the perforations. Foreign body reaction was pronounced with CollaMend and Surgisis, leading to persistent granulomatous inflammation. Shrinkage was excessive with Surgisis, whereas Tutomesh and Peripatch yielded sufficient anti-adhesion and elicited no foreign body reaction. Conclusion: At 2 months, cross-linked and non-cross-linked biologic hernia implants were poorly integrated. Cross-linking led to a more pronounced foreign body reaction. Less inflammatory response may reduce local complications, but did not enhance implant integration in this study. [ABSTRACT FROM AUTHOR]
- Published
- 2011
- Full Text
- View/download PDF
22. A New Augmentation Method for Improved Screw Fixation in Fragile Bone.
- Author
-
Raina DB, Markevičiūtė V, Stravinskas M, Kok J, Jacobson I, Liu Y, Sezgin EA, Isaksson H, Zwingenberger S, Tägil M, Tarasevičius Š, and Lidgren L
- Abstract
Pertrochanteric fractures (TF) due to osteoporosis constitute nearly half of all proximal femur fractures. TFs are treated with a surgical approach and fracture fixation is achieved using metallic fixation devices. Poor quality cancellous bone in osteoporotic patients makes anchorage of a fixation device challenging, which can lead to failure of the fracture fixation. Methods to reinforce the bone-implant interface using bone cement (PMMA) and other calcium phosphate cements in TFs have been described earlier but a clear evidence on the advantage of using such biomaterials for augmentation is weak. Furthermore, there is no standardized technique for delivering these biomaterials at the bone-implant interface. In this study, we firstly describe a method to deliver a calcium sulphate/hydroxyapatite (CaS/HA) based biomaterial for the augmentation of a lag-screw commonly used for TF fixation. We then used an osteoporotic Sawbones model to study the consequence of CaS/HA augmentation on the immediate mechanical anchorage of the lag-screw to osteoporotic bone. Finally, as a proof-of-concept, the method of delivering the CaS/HA biomaterial at the bone-implant interface as well as spreading of the CaS/HA material at this interface was tested in patients undergoing treatment for TF as well as in donated femoral heads. The mechanical testing results indicated that the CaS/HA based biomaterial increased the peak extraction force of the lag-screw by 4 times compared with un-augmented lag-screws and the results were at par with PMMA. The X-ray images from the patient series showed that it was possible to inject the CaS/HA material at the bone-implant interface without applying additional pressure and the CaS/HA material spreading was observed at the interface of the lag-screw threads and the bone. Finally, the spreading of the CaS/HA material was also verified on donated femoral heads and micro-CT imaging indicated that the entire length of the lag-screw threads was covered with the CaS/HA biomaterial. In conclusion, we present a novel method for augmenting a lag-screw in TFs, which could potentially reduce the risk of fracture fixation failure and reoperation in fragile osteoporotic patients., Competing Interests: LL is a board member and founder of Bonesupport, AB, Sweden and board member of OrthoCell Ltd. Australia. LL, MT, and DBR hold shares in Moroxite AB, Sweden. The remaining authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2022 Raina, Markevičiūtė, Stravinskas, Kok, Jacobson, Liu, Sezgin, Isaksson, Zwingenberger, Tägil, Tarasevičius and Lidgren.)
- Published
- 2022
- Full Text
- View/download PDF
23. Improved bioactivity of GUMMETAL
- Author
-
Shiva Kamini, Divakarla, Seiji, Yamaguchi, Tadashi, Kokubo, Dong-Wook, Han, Jae Ho, Lee, and Wojciech, Chrzanowski
- Subjects
atomic force microscopy ,biocompatibility ,bioactivity ,Short Communications ,orthopaedic implants ,titanium implants ,Implant integration - Abstract
The leading reason for implant revision surgery globally is lack of implant integration with surrounding bone. A new titanium alloy GUMMETAL® (Ti59Nb36Ta2Zr3O0.3) is currently used in biomedical devices and has a Young’s modulus that is better matched to bone. The surface was subject to NaOH, CaCl2, heat and water treatment (BioGum) after which the surfaces were evaluated using atomic force microscope, scanning electron microscope, X-ray diffractometer and elemental analysis using energy dispersive X-ray. To demonstrate enhanced bone bonding ability and cytocompatibility, apatite formation in simulated body fluid and in vitro stem cell attachment, proliferation and cytoskeleton organisation were examined. The formation of a ~200 nm nanoscale needle-like calcium titanate network on the surface following treatment was revealed and upon soaking in simulated body fluid, the formation of a ~5 µm layer of apatite. Metabolic activity of rat bone marrow stem cells on BioGum was increased in comparison to control and the cell number appeared greater, with more elongated morphology as early as 2 h post-seeding. This positions the modification as a simple and potentially universal technology for the improvement of implant integration.
- Published
- 2018
24. Vitamin D Deficiency and Early Implant Failure: Outcomes from a Pre-surgical Supplementation Program on Vitamin D Levels and Antioxidant Scores.
- Author
-
Paz A, Stanley M, Mangano FG, and Miron RJ
- Subjects
- Dietary Supplements, Humans, Risk Factors, Vitamin D, Antioxidants, Vitamin D Deficiency
- Abstract
Purpose: Accumulating evidence has shown that vitamin D deficiency has been linked with an up to 300% increase in early implant failure. The aim of this study was to investigate a comprehensive pre-surgical dental support program (DentaMedica) on its ability to increase vitamin D and antioxidant levels prior to implant surgery., Materials and Methods: Twenty patients were enrolled in this study. To quantify vitamin D levels, two in-office vitamin D finger-prick tests (10-15 min in length) were compared to levels obtained from a standard laboratory blood test. An antioxidant testing device was also utilised to investigate the impact of this pre-surgical supplementation program on antioxidant scores 0 and 6 weeks post supplementation., Results: It was first found that 65% of the population had an initial vitamin D deficiency (below 30 ug/ml). After supplementation, vitamin D levels increased from an average of 24.76 ng/ml to 50.11 ng/ml (ranging from 38 to 85.50 ng/ml). No statsitcally significant differences were observed between any of the 3 testing devices (2 in-office finger-prick tests and a standard blood sample). Initial antioxidant levels registered on the biophotonic unit averaged an antioxidant score of 27250 ± 10992.22. Following supplementation, an increase of 54% from baseline values (41950 ± 9276.31) was reported., Conclusion: The results from this study show convincingly that the majority of the tested population was vitamin D deficient. It was further found that both in-office finger-prick devices demonstrated results comparable to standard lab scores (usually within an average 2-3 ng/ml). Following supplementation, all patients reached sufficient levels following this 4-6 week pre-surgical supplementation program specific to implant dentistry.
- Published
- 2021
- Full Text
- View/download PDF
25. Influence of gait loads on implant integration in rat tibiae: Experimental and numerical analysis
- Author
-
Anselm Wiskott, Marco Piccinini, Joël Cugnoni, Patrick Ammann, and John Botsis
- Subjects
Bone loss ,Materials science ,Bone disuse atrophy ,Finite Element Analysis ,Biomedical Engineering ,Biophysics ,Bone healing ,Weight-Bearing ,Gait (human) ,Finite element ,Materials Testing ,medicine ,Animals ,Orthopedics and Sports Medicine ,Tibia ,Gait ,Titanium ,Rehabilitation ,Prostheses and Implants ,Rat tibia ,ddc:617.6 ,Rats ,Implant integration ,medicine.anatomical_structure ,Musculoskeletal loads ,ddc:618.97 ,Rat ,Cortical bone ,Implant ,Biomedical engineering - Abstract
Implanted rat bones play a key role in studies involving fracture healing, bone diseases or drugs delivery among other themes. In most of these studies the implants integration also depends on the animal daily activity and musculoskeletal loads, which affect the implants mechanical environment. However, the tissue adaption to the physiological loads is often filtered through control groups or not inspected. This work aims to investigate experimentally and numerically the effects of the daily activity on the integration of implants inserted in the rat tibia, and to establish a physiological loading condition to analyse the pen-implant bone stresses during gait. Two titanium implants, single and double cortex crossing, are inserted in the rat tibia. The animals are caged under standard conditions and divided in three groups undergoing progressive integration periods. The results highlight a time-dependent increase of bone samples with significant cortical bone loss. The phenomenon is analysed through specimen-specific Finite Element models involving purpose-built musculoskeletal loads. Different boundary conditions replicating the post-surgery bone-implant interaction are adopted. The effects of the gait loads on the implants integration are quantified and agree with the results of the experiments. The observed cortical bone loss can be considered as a transient state of integration due to bone disuse atrophy, initially triggered by a loss of bone-implant adhesion and subsequently by a cyclic opening of the interface. (C) 2014 Elsevier Ltd. All rights reserved.
- Published
- 2014
26. Controlling porous titanium/soft tissue interactions with an innovative surface chemical treatment: Responses of macrophages and fibroblasts.
- Author
-
Barthes, Julien, Cazzola, Martina, Muller, Celine, Dollinger, Camille, Debry, Christian, Ferraris, Sara, Spriano, Silvia, and Vrana, Nihal E.
- Subjects
- *
SURFACE preparation , *CONNECTIVE tissue cells , *SURFACE interactions , *TITANIUM , *CELL migration - Abstract
In order to create a stable interface with the host tissue, porous implants are widely used to ensure the in-growth of the cells and the colonization of the implant. An ideal porous implant should have a 3D architecture that enables fast migration of incoming cells while not inducing a significant pro-inflammatory response by the immune cells. Moreover, in patients where the healing is impeded (patients with co-morbidities and metabolic diseases), porosity by itself is not enough for fast colonization, and the surface properties of the implant should also be controlled. In this study, we present a controlled oxidation-based surface treatment of microbead-based porous titanium implants which not only increases the colonization by connective tissue cells but also decreases the macrophage attachment. The treatment created a nanotextured surface on the implants with an acidic shift of isoelectric point (from 4.09 to 3.09) without endangering implant's mechanical integrity. The attachment and metabolic activity of activated macrophages were significantly lower on treated surfaces with an increase in the secretion of anti-inflammatory IL-1RA and a decrease in pro-fibrotic CCL-18. Human fibroblasts proliferated faster on the treated surfaces over 14 days with near complete colonization of the whole thickness of the implant with an accompanying an increase in the secretion of TGF-beta. The surface treated samples demonstrated partial filling of the entire pores. We demonstrated that the use of nanoscale surface treatments that can be applied to the whole internal surface of porous titanium implants can significantly alter both the immune response and the colonization of the implants and can be used to fine-tune and personalize implant interfaces according to patient needs. Controlled oxidation of porous microbead based titanium implants result in more control over immune response and increased in-growth by connective tissue cells. Unlabelled Image • Controlled Oxidation creates nanotextured surfaces on porous titanium structures • The nanoscale treatment had a direct effect on the cellular attachment and migration through the porous titanium implants • The effect is cell type dependent, where the attachment and migration of fibroblasts were improved by the treatment while the macrophage attachment was diminished. [ABSTRACT FROM AUTHOR]
- Published
- 2020
- Full Text
- View/download PDF
27. Management of large perforations of the sinus mucosa with PRGF-Endoret® platelet concentrate.
- Author
-
Giacomello MS, Mortellaro C, Giacomello A, Scali JJ, and Greco Lucchina A
- Subjects
- Bone Regeneration, Humans, Maxilla diagnostic imaging, Maxilla surgery, Middle Aged, Mucous Membrane, Wound Healing, Dental Implants, Maxillary Sinus diagnostic imaging, Maxillary Sinus surgery
- Abstract
The aim of the present study is to describe a new technique through which it is possible to complete the maxillary sinus lift procedure even in case of severe damage or complete removal of the sinus mucosa using the PRGF-Endoret® platelet concentrate. Eighteen patients (ratio F:M=4:5; average age: 58.2 years; DS: 8.85 years) with severe perforation (more than 10 millimetres of diameter) of the sinus mucosa during the maxillary sinus lift procedure were selected. Normally the procedure is interrupted due to impossible stabilization of the graft material inside the subantral cavity. On the contrary, our protocol foreseen the sealing of the perforation using the PRGF autologous gel membranes or the creation of a new sinus pseudomembrane through which the graft material was covered. The PRGF-Endoret were obtained according to the protocol developed by BTI (Biotechnology Institute - Vitoria, Spain). In 14 cases out of 18 implant fixtures were concurrently inserted while in 4 cases the fixture insertion was postponed after 6 months: 37 fixtures were inserted (27 at the same time and 10 after 6 months). 2 months after surgery the CBCT showed a correct pneumatization of the maxillary sinus in 16 patients out of 18 (89% of cases), while after 12 months the radiological normalization of the maxillary sinus was present in 17 patients out of 18, bringing the healing rate to 94% of cases. Regarding implant healing, 2 out of 37 implants inserted were lost in the first month after the surgical phase, whereas 12 months after prosthesis application the other 35 implants were perfectly osteointegrated with a healing rate equal to 94.6% of the fixtures. 36 months after the surgery all the fixtures were osteointegrated (35 of 37 implants with a percentage of 94.6% of success). We may conclude that the use of PRGF allowed to complete the sinus lift even in case of severe perforation of the sinus mucosa or its total removal thanks to its capability to stabilize the graft, its antibacterial and antifungal activity and its anabolic effect and favouring bone regeneration., (Copyright 2020 Biolife Sas. www.biolifesas.org.)
- Published
- 2021
- Full Text
- View/download PDF
28. Surface Modification Strategies to Improve the Osseointegration of Poly(etheretherketone) and Its Composites.
- Author
-
Buck E, Li H, and Cerruti M
- Subjects
- Animals, Benzophenones, Durapatite, Humans, Polymers, Surface Properties, Titanium therapeutic use, Coated Materials, Biocompatible therapeutic use, Ketones therapeutic use, Osseointegration drug effects, Polyethylene Glycols therapeutic use
- Abstract
In the last 5 years, a wide variety of surface modification strategies are explored to improve the integration of poly(etheretherketone) (PEEK) implants with bone. Since PEEK does not support bone on-growth, its surface properties need to be tailored to promote osteogenesis at the bone-implant interface. Surface modifications applied to achieve this response range from simple surface morphology changes to the deposition of osteoconductive coatings. Of the many methods, titanium and/or hydroxyapatite coatings, extrusion to create surface pores, and an accelerated neutral atom beam treatment have been approved by the U.S. Food and Drug Administration to improve the integration of PEEK spinal cages. The success of these surface modifications brings hope for the clinical translation of other techniques in the future, but there are several limitations that may be preventing other treatments from reaching the clinic. This review describes numerous strategies that have been applied to PEEK-based implants for improving their osseointegration and enhancing their antibacterial properties. The review concludes with a discussion about future directions for the field and provides suggestions for advancing clinical translation of surface-modified PEEK implants to improve the lives of patients in need of these implants., (© 2019 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)
- Published
- 2020
- Full Text
- View/download PDF
29. Mechanical regulation of bone formation and resorption around implants in a mouse model of osteopenic bone.
- Author
-
Li Z, Betts D, Kuhn G, Schirmer M, Müller R, and Ruffoni D
- Subjects
- Animals, Bone Diseases, Metabolic diagnostic imaging, Bone Diseases, Metabolic pathology, Disease Models, Animal, Female, Mice, X-Ray Microtomography, Bone Density, Bone Diseases, Metabolic metabolism, Bone Resorption, Bone-Implant Interface, Implants, Experimental, Osteogenesis
- Abstract
Although mechanical stimulation is considered a promising approach to accelerate implant integration, our understanding of load-driven bone formation and resorption around implants is still limited. This lack of knowledge may delay the development of effective loading protocols to prevent implant loosening, especially in osteoporosis. In healthy bone, formation and resorption are mechanoregulated processes. In the intricate context of peri-implant bone regeneration, it is not clear whether bone (re)modelling can still be load-driven. Here, we investigated the mechanical control of peri-implant bone (re)modelling with a well-controlled mechanobiological experiment. We applied cyclic mechanical loading after implant insertion in tail vertebrae of oestrogen depleted mice and we monitored peri-implant bone response by in vivo micro-CT. Experimental data were combined with micro-finite element simulations to estimate local tissue strains in (re)modelling locations. We demonstrated that a substantial increase in bone mass around the implant could be obtained by loading the entire bone. This augmentation could be attributed to a large reduction in bone resorption rather than to an increase in bone formation. We also showed that following implantation, mechanical regulation of bone (re)modelling was transiently lost. Our findings should help to clarify the role of mechanical stimulation on the maintenance of peri-implant bone mass.
- Published
- 2019
- Full Text
- View/download PDF
30. Improved bioactivity of GUMMETAL ® , Ti 59 Nb 36 Ta 2 Zr 3 O 0.3 , via formation of nanostructured surfaces.
- Author
-
Divakarla SK, Yamaguchi S, Kokubo T, Han DW, Lee JH, and Chrzanowski W
- Abstract
The leading reason for implant revision surgery globally is lack of implant integration with surrounding bone. A new titanium alloy GUMMETAL
® (Ti59 Nb36 Ta2 Zr3 O0.3 ) is currently used in biomedical devices and has a Young's modulus that is better matched to bone. The surface was subject to NaOH, CaCl2 , heat and water treatment (BioGum) after which the surfaces were evaluated using atomic force microscope, scanning electron microscope, X-ray diffractometer and elemental analysis using energy dispersive X-ray. To demonstrate enhanced bone bonding ability and cytocompatibility, apatite formation in simulated body fluid and in vitro stem cell attachment, proliferation and cytoskeleton organisation were examined. The formation of a ~200 nm nanoscale needle-like calcium titanate network on the surface following treatment was revealed and upon soaking in simulated body fluid, the formation of a ~5 µm layer of apatite. Metabolic activity of rat bone marrow stem cells on BioGum was increased in comparison to control and the cell number appeared greater, with more elongated morphology as early as 2 h post-seeding. This positions the modification as a simple and potentially universal technology for the improvement of implant integration., Competing Interests: Declaration of conflicting interests: The author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.- Published
- 2018
- Full Text
- View/download PDF
31. Does PRP enhance bone integration with grafts, graft substitutes, or implants? A systematic review
- Author
-
Elizaveta Kon, Alice Roffi, Maurilio Marcacci, Giuseppe Filardo, Roffi A, Filardo G, Kon E, Marcacci M, ARAG - AREA FINANZA E PARTECIPATE, DIPARTIMENTO DI SCIENZE BIOMEDICHE E NEUROMOTORIE, Facolta' di MEDICINA e CHIRURGIA, Da definire, and AREA MIN. 06 - Scienze mediche
- Subjects
Platelets ,medicine.medical_specialty ,PRP ,Bone Regeneration ,Dentistry ,Regenerative medicine ,Rheumatology ,Implant integration ,medicine ,Animals ,Humans ,Orthopedics and Sports Medicine ,Bone regeneration ,Bone ,Autografts ,Bone Transplantation ,business.industry ,Platelet-Rich Plasma ,Bone implant ,Soft tissue ,Prostheses and Implants ,Allografts ,Surgery ,Clinical Practice ,Bone transplantation ,Platelet-rich plasma ,Implant ,business ,Research Article - Abstract
Background Several bone implants are applied in clinical practice, but none meets the requirements of an ideal implant. Platelet-rich plasma (PRP) is an easy and inexpensive way to obtain growth factors in physiologic proportions that might favour the regenerative process. The aim of this review is to analyse clinical studies in order to investigate the role of PRP in favouring bone integration of graft, graft substitutes, or implants, and to identify the materials for which the additional use of PRP might be associated with superior osseo- and soft tissues integration. Methods A search on PubMed database was performed considering the literature from 2000 to 2012, using the following string: ("Bone Substitutes"[Mesh] OR "Bone Transplantation"[Mesh] OR "Bone Regeneration"[Mesh] OR "Osseointegration"[Mesh]) AND ("Blood Platelets"[Mesh] OR "Platelet-Rich Plasma"[Mesh]). After abstracts screening, the full-texts of selected papers were analyzed and the papers found from the reference lists were also considered. The search focused on clinical applications documented in studies in the English language: levels of evidence included in the literature analysis were I, II and III. Results Literature analysis showed 83 papers that fulfilled the inclusion criteria: 26 randomized controlled trials (RCT), 14 comparative studies, 29 case series, and 14 case reports. Several implant materials were identified: 24 papers on autologous bone, 6 on freeze-dried bone allograft (FDBA), 16 on bovine porous bone mineral (BPBM), 9 on β-tricalcium phosphate (β-TCP), 4 on hydroxyapatite (HA), 2 on titanium (Ti), 1 on natural coral, 1 on collagen sponge, 1 on medical-grade calcium sulphate hemihydrate (MGCSH), 1 on bioactive glass (BG) and 18 on a combination of biomaterials. Only 4 papers were related to the orthopaedic field, whereas the majority belonged to clinical applications in oral/maxillofacial surgery. Conclusions The systematic research showed a growing interest in this approach for bone implant integration, with an increasing number of studies published over time. However, knowledge on this topic is still preliminary, with the presence mainly of low quality studies. Many aspects still have to be understood, such as the biomaterials that can benefit most from PRP and the best protocol for PRP both for production and application.
- Published
- 2013
32. Influence of Statins locally applied from orthopedic implants on osseous integration
- Author
-
Britt Wildemann, Kathrin Kaeppler, Gerhard Schmidmaier, Stephan Pauly, Norbert P. Haas, and David Alexander Back
- Subjects
Simvastatin ,Osteolysis ,Time Factors ,lcsh:Diseases of the musculoskeletal system ,Polyesters ,Dentistry ,Bone healing ,Prosthesis Design ,Bone morphogenetic protein 2 ,Local application ,law.invention ,Intramedullary rod ,Prosthesis Implantation ,Rats, Sprague-Dawley ,Rheumatology ,Coated Materials, Biocompatible ,law ,Osseointegration ,medicine ,Animals ,BMP ,Femur ,Orthopedics and Sports Medicine ,Fixation (histology) ,Titanium ,Dose-Response Relationship, Drug ,business.industry ,Statins ,medicine.disease ,Biomechanical Phenomena ,Rats ,Implant integration ,Radiography ,Female ,Implant ,Hydroxymethylglutaryl-CoA Reductase Inhibitors ,lcsh:RC925-935 ,business ,medicine.drug ,Research Article - Abstract
Background Simvastatin increases the expression of bone morphogenetic protein 2 (BMP-2) in osteoblasts, therefore it is important to investigate the influence of statins on bone formation, fracture healing and implant integration. The aim of the present study was to investigate the effect of Simvastatin, locally applied from intramedullary coated and bioactive implants, on bone integration using biomechanical and histomorphometrical analyses. Methods Eighty rats received retrograde nailing of the femur with titanium implants: uncoated vs. polymer-only (poly(D,L-lactide)) vs. polymer plus drug coated (either Simvastatin low- or high dosed; “SIM low/ high”). Femurs were harvested after 56 days for radiographic and histomorphometric or biomechanical analysis (push-out). Results Radiographic analysis revealed no pathological findings for animals of the control and SIM low dose group. However, n=2/10 animals of the SIM high group showed osteolysis next to the implant without evidence of bacterial infection determined by microbiological analysis. Biomechanical results showed a significant decrease in fixation strength for SIM high coated implants vs. the control groups (uncoated and PDLLA). Histomorphometry revealed a significantly reduced total as well as direct bone/implant contact for SIM high- implants vs. controls (uncoated and PDLLA-groups). Total contact was reduced for SIM low vs. uncoated controls. Significantly reduced new bone formation was measured around SIM high coated implants vs. both control groups. Conclusions This animal study suggests impaired implant integration with local application of Simvastatin from intramedullary titanium implants after 8 weeks when compared to uncoated or carrier-only coated controls.
- Full Text
- View/download PDF
33. Peri-implant bone adaptations to overloading in rat tibiae: experimental investigations and numerical predictions
- Author
-
John Botsis, Anselm Wiskott, Marco Piccinini, Patrick Ammann, and Joël Cugnoni
- Subjects
musculoskeletal diseases ,medicine.medical_specialty ,Lateral stability ,Materials science ,Bone density ,0206 medical engineering ,Finite Element Analysis ,02 engineering and technology ,Peri implant bone ,Osseointegration ,Rats, Sprague-Dawley ,bone augmentation ,03 medical and health sciences ,0302 clinical medicine ,Implants, Experimental ,Bone Density ,medicine ,Animals ,Tibia ,specimen-specific ,adaptation algorithm ,invivo stimulation ,ddc:616 ,Bone mineral ,Dental Implants ,Titanium ,Dental Implantation, Endosseous ,030206 dentistry ,musculoskeletal system ,020601 biomedical engineering ,ddc:617.6 ,Surgery ,Biomechanical Phenomena ,Rats ,finite element ,in vivo stimulation ,Female ,Bone adaptation ,Implant ,Stress, Mechanical ,Oral Surgery ,implant integration ,Tomography, X-Ray Computed ,Biomedical engineering - Abstract
Objectives(i) To assess the effects of mechanical overloading on implant integration in rat tibiae, and (ii) to numerically predict peri-implant bone adaptation. Materials and methodsTranscutaneous titanium implants were simultaneously placed into both tibiae of rats (n=40). After 2weeks of integration, the implants of the right tibiae were stimulated daily for 4weeks with loads up to 5N (corresponding to peak equivalent strains of 3300500 epsilon). The effects of stimulation were assessed by exvivo mechanical tests and quantification of bone mineral density (BMD) in selected regions of interests (ROIs). Specimen-specific finite element models were generated and processed through an iterative algorithm to mimic bone adaptation. ResultsBilateral implantation provoked an unstable integration that worsened when mild (2-4N) external loads were applied. In contrast, a stimulation at 5N tended to counterbalance the harmful effects of daily activity and, if applied to well-integrated specimens, significantly augmented the implants' resistance to failure (force: +73% P
Catalog
Discovery Service for Jio Institute Digital Library
For full access to our library's resources, please sign in.