Hip Implant Design With Three-Dimensional Porous Architecture of Optimized Graded Density

2018 ◽  
Vol 140 (11) ◽  
Author(s):  
Yingjun Wang ◽  
Sajad Arabnejad ◽  
Michael Tanzer ◽  
Damiano Pasini
Keyword(s):  
Bone Resorption ◽  
Bone Loss ◽  
Three Dimensional ◽  
Stress Shielding ◽  
Implant Design ◽  
Fatigue Properties ◽  
Uniform Density ◽  
Hip Implant ◽  
Porous Implant ◽  
Porous Architecture

Even in a well-functioning total hip replacement, significant peri-implant bone resorption can occur secondary to stress shielding. Stress shielding is caused by an undesired mismatch of elastic modulus between the stiffer implant and the adjacent bone tissue. To address this problem, we present here a microarchitected hip implant that consists of a three-dimensional (3D) graded lattice material with properties that are mechanically biocompatible with those of the femoral bone. Asymptotic homogenization (AH) is used to numerically determine the mechanical and fatigue properties of the implant, and a gradient-free scheme of topology optimization is used to find the optimized relative density distribution of the porous implant under multiple constraints dictated by implant micromotion, pore size, porosity, and minimum manufacturable thickness of the cell elements. Obtained for a 38-year-old patient femur, bone resorption is assessed by the difference in strain energy between the implanted bone and the intact bone in the postoperative conditions. The numerical results suggest that bone loss for the optimized porous implant is only 42% of that of a fully solid implant, here taken as benchmark, and 79% of that of a porous implant with uniform density. The architected hip implant presented in this work shows clinical promise in reducing bone loss while preventing implant micromotion, thereby contributing to reduce the risk of periprosthetic fracture and the probability of revision surgery.

scholarly journals Long-term bone remodelling around ‘legendary’ cementless femoral stems

2018 ◽  
Vol 3 (2) ◽  
pp. 45-57 ◽  
Author(s):  
Charles Rivière ◽  
Guido Grappiolo ◽  
Charles A. Engh ◽  
Jean-Pierre Vidalain ◽  
Antonia-F. Chen ◽  
...  
Keyword(s):  
Bone Loss ◽  
Bone Remodelling ◽  
Bone Ingrowth ◽  
Stress Shielding ◽  
Implant Design ◽  
Periprosthetic Bone ◽  
Femoral Stems ◽  
Periprosthetic Bone Loss ◽  
Load Pattern

Bone remodelling around a stem is an unavoidable long-term physiological process highly related to implant design. For some predisposed patients, it can lead to periprosthetic bone loss secondary to severe stress-shielding, which is thought to be detrimental by contributing to late loosening, late periprosthetic fracture, and thus rendering revision surgery more complicated. However, these concerns remain theoretical, since late loosening has yet to be documented among bone ingrowth cementless stems demonstrating periprosthetic bone loss associated with stress-shielding. Because none of the stems replicate the physiological load pattern on the proximal femur, each stem design is associated with a specific load pattern leading to specific adaptive periprosthetic bone remodelling. In their daily practice, orthopaedic surgeons need to differentiate physiological long-term bone remodelling patterns from pathological conditions such as loosening, sepsis or osteolysis. To aid in that process, we decided to clarify the behaviour of the five most used femoral stems. In order to provide translational knowledge, we decided to gather the designers’ and experts’ knowledge and experience related to the design rationale and the long-term bone remodelling of the following femoral stems we deemed ‘legendary’ and still commonly used: Corail (Depuy); Taperloc (Biomet); AML (Depuy); Alloclassic (Zimmer); and CLS-Spotorno (Zimmer).Cite this article: EFORT Open Rev 2018;3:45-57. DOI: 10.1302/2058-5241.3.170024

scholarly journals Fabrication of Low-Cost Hip Implant using Direct Metal Laser Sintering Technique

2019 ◽  
Vol 8 (4) ◽  
pp. 4544-4547
Keyword(s):  
Finite Element ◽  
Low Cost ◽  
Fibrous Tissue ◽  
Three Dimensional ◽  
Stress Shielding ◽  
Element Analysis ◽  
Hip Implant ◽  
Neck Shaft Angle ◽  
Hip Morphology ◽  
Direct Laser

Total hip replacement (THR) is the most popular surgery been performed in orthopedic surgery due to the inclination of musculoskeletal disorder and the aging population worldwide. However, the implant’s cost-burdened the patient, especially in the ASEAN region. The main objective of this study was to fabricate the low-cost hip implant using direct laser metal sintering (DMLS). The framework starts with the three dimensional of hip anthropometric datasets from computed tomography scanner, followed with the design of hip implant, computational analysis using finite element, and finally fabrication using DMLS technique. The morphological results demonstrated the value of neck-shaft angle was 130.46º, and the femoral head offset of 30.35 mm. The finite element analysis showed strain distribution was 65 MPa for the implant in metaphyseal region and 110 MPa for intact femur under staircase physiological loading which indicated inhibition of stress shielding at medical calcar region, and micromotion was 4.8 µm which prevent the formation of fibrous tissue and promoting osseointegration between implant-bone interfaces. This study proposed the fabrication using the DMLS technique, which produced accurate implant with low-cost, which suits the ASEAN hip morphology that prolongs implant lifetime.

Assessment of Bone Resorption after Secondary Alveolar Bone Grafting Using Three-Dimensional Computed Tomography: A Three-Year Study

2007 ◽  
Vol 44 (2) ◽  
pp. 142-148 ◽  
Author(s):  
Matthias Feichtinger ◽  
Rudolf Mossböck ◽  
Hans Kärcher
Keyword(s):  
Computed Tomography ◽  
Bone Resorption ◽  
Bone Loss ◽  
Bone Grafting ◽  
Alveolar Bone ◽  
Three Dimensional ◽  
Two Dimensional ◽  
Alveolar Bone Grafting ◽  
Three Dimensional Models ◽  
Secondary Alveolar Bone Grafting

Objective: Secondary bone grafting plays an important role in the dental rehabilitation of patients with clefts of the lip, alveolus, and palate. A major complication of this surgical technique is resorption of the grafted bone transplant. Conventional two-dimensional radiographs are often inconclusive and do not demonstrate the true deficit. The main objective of this study was to evaluate the amount and exact location of bone loss on the basis of three-dimensional models over a period of 3 years. Design: Twenty-four patients with unilateral cleft palate were included in this prospective study. Axial computed tomography scans of all patients were taken immediately preoperatively, and 1, 2, and 3 years postoperatively. Volumetric analysis was performed on three-dimensional models of the cleft defects and the bone bridges using three-dimensional computed tomography. Interventions: All patients were treated by secondary alveolar bone grafting prior to eruption of the permanent canine. Results: Extensive bone resorption was found in the bucco-palatal dimension of the alveolar portion of the transplant. The success rate of secondary bone grafting was high in cases of rapid orthodontic gap closures. The mean bone loss in the first year after surgery was 49.5%. The transplants remained almost constant in the following 2 years. Conclusions: Radiographic scales based on orthopantomography only evaluate the vertical dimension of the transplants. This study, however, showed that bone resorption in the transversal dimension is clearly underestimated with conventional two-dimensional radiographs.

scholarly journals Topology Optimisation for Compliant Hip Implant Design and Reduced Strain Shielding

Materials ◽  
2021 ◽  
Vol 14 (23) ◽  
pp. 7184
Author(s):  
Nathanael Tan ◽  
Richard van Arkel
Keyword(s):  
Load Transfer ◽  
Stress Shielding ◽  
Implant Design ◽  
Topology Optimisation ◽  
Hip Implant ◽  
Implant Survivorship ◽  
Hip Stems ◽  
Bone Structures ◽  
Optimisation Techniques ◽  
Strain Shielding

Stiff total hip arthroplasty implants can lead to strain shielding, bone loss and complex revision surgery. The aim of this study was to develop topology optimisation techniques for more compliant hip implant design. The Solid Isotropic Material with Penalisation (SIMP) method was adapted, and two hip stems were designed and additive manufactured: (1) a stem based on a stochastic porous structure, and (2) a selectively hollowed approach. Finite element analyses and experimental measurements were conducted to measure stem stiffness and predict the reduction in stress shielding. The selectively hollowed implant increased peri-implanted femur surface strains by up to 25 percentage points compared to a solid implant without compromising predicted strength. Despite the stark differences in design, the experimentally measured stiffness results were near identical for the two optimised stems, with 39% and 40% reductions in the equivalent stiffness for the porous and selectively hollowed implants, respectively, compared to the solid implant. The selectively hollowed implant’s internal structure had a striking resemblance to the trabecular bone structures found in the femur, hinting at intrinsic congruency between nature’s design process and topology optimisation. The developed topology optimisation process enables compliant hip implant design for more natural load transfer, reduced strain shielding and improved implant survivorship.

scholarly journals A three-dimensional finite element analysis on the effects of implant materials and designs on periprosthetic tibial bone resorption

PLoS ONE ◽  
2021 ◽  
Vol 16 (2) ◽  
pp. e0246866
Author(s):  
Hyung Jun Park ◽  
Tae Soo Bae ◽  
Seung-Baik Kang ◽  
Hyeong Ho Baek ◽  
Moon Jong Chang ◽  
...  
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Bone Resorption ◽  
Three Dimensional ◽  
Implant Design ◽  
Element Analysis ◽  
Implant Materials ◽  
Tibial Bone ◽  
Dimensional Finite Element ◽  
Three Dimensional Finite Element

Introduction Implant material is a more important factor for periprosthetic tibial bone resorption than implant design after total knee arthroplasty (TKA). The virtual perturbation study was planned to perform using single case of proximal tibia model. We determined whether the implant materials’ stiffness affects the degree of periprosthetic tibial bone resorption, and whether the effect of material change with the same implant design differed according to the proximal tibial plateau areas. Materials and methods This three-dimensional finite element analysis included two cobalt-chromium (CoCr) and two titanium (Ti) tibial implants with different designs. They were implanted into the proximal tibial model reconstructed using extracted images from computed tomography. The degree of bone resorption or formation was measured using the strain energy density after applying axial load. The same analysis was performed after exchanging the materials while maintaining the design of each implant. Results The degree of periprosthetic tibial bone resorption was not determined by the type of implant materials alone. When the implant materials were changed from Ti to CoCr, the bone resorption in the medial compartment increased and vice versa. The effect of material composition’s change on anterior and posterior areas varied accordingly. Conclusions Although the degree of bone resorption was associated with implant materials, it differed depending on the design of each implant. The effect on the degree of bone resorption according to the materials after TKA should be evaluated while concomitantly considering design.

Comparing Contact Pressure Induced by a Conventional Complete Denture and an Implant-Retained Overdenture

2014 ◽  
Vol 553 ◽  
pp. 384-389 ◽  
Author(s):  
Jun Ning Chen ◽  
Rohana Ahmad ◽  
Michael V. Swain ◽  
Wei Li ◽  
Hanako Suenaga ◽  
...  
Keyword(s):  
Bone Resorption ◽  
Bone Loss ◽  
Contact Pressure ◽  
Clinical Investigation ◽  
Three Dimensional ◽  
Element Model ◽  
Complete Denture ◽  
Local Bone ◽  
Dimensional Finite Element ◽  
Three Dimensional Finite Element

Implant-retained overdenture has been widely applied as a solution to edentulous ageing; however, a major concern for the denture wearers is bone resorption induced by the prosthetic interaction with soft tissue and bone. Early studies have revealed that the bone resorption is associated with the disturbance to the mucosa blood flow. This study aimed to investigate the contact pressure induced by an implant-retained overdenture, compared to a conventional complete denture without implants, which implies the potential bone resorption for clinical investigation. A three-dimensional finite element model of a full jaw, including mandible bone, mucosa, and denture, was created through a reverse engineering method based on CBCT images, in which the hyperelastic behaviour of mucosa was determined by curve-fitting to the clinical measurement, for a more realistic response. It is found that the location of the bone loss differed between the implant retained and non-implant complete dentures. With the implants, the denture displaced more at posterior ends towards the mucosa bearing area, leading to higher contact pressure accounted for more severe local bone loss.

scholarly journals The Symmetric 3D Organization of Connective Tissue around Implant Abutment: A Key-Issue to Prevent Bone Resorption

Symmetry ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 1126
Author(s):  
Giovanna Iezzi ◽  
Francesca Di Lillo ◽  
Michele Furlani ◽  
Marco Degidi ◽  
Adriano Piattelli ◽  
...  
Keyword(s):  
Bone Resorption ◽  
Connective Tissue ◽  
Inflammatory Cell ◽  
Soft Tissues ◽  
Three Dimensional ◽  
Collagen Fibers ◽  
Inflammatory Cell Infiltration ◽  
Cell Infiltration ◽  
Oral Epithelium ◽  
Implant Abutment

Symmetric and well-organized connective tissues around the longitudinal implant axis were hypothesized to decrease early bone resorption by reducing inflammatory cell infiltration. Previous studies that referred to the connective tissue around implant and abutments were based on two-dimensional investigations; however, only advanced three-dimensional characterizations could evidence the organization of connective tissue microarchitecture in the attempt of finding new strategies to reduce inflammatory cell infiltration. We retrieved three implants with a cone morse implant–abutment connection from patients; they were investigated by high-resolution X-ray phase-contrast microtomography, cross-linking the obtained information with histologic results. We observed transverse and longitudinal orientated collagen bundles intertwining with each other. In the longitudinal planes, it was observed that the closer the fiber bundles were to the implant, the more symmetric and regular their course was. The transverse bundles of collagen fibers were observed as semicircular, intersecting in the lamina propria of the mucosa and ending in the oral epithelium. No collagen fibers were found radial to the implant surface. This intertwining three-dimensional pattern seems to favor the stabilization of the soft tissues around the implants, preventing inflammatory cell apical migration and, consequently, preventing bone resorption and implant failure. This fact, according to the authors’ best knowledge, has never been reported in the literature and might be due to the physical forces acting on fibroblasts and on the collagen produced by the fibroblasts themselves, in areas close to the implant and to the symmetric geometry of the implant itself.

scholarly journals Decitabine Inhibits Bone Resorption in Periodontitis by Upregulating Anti-Inflammatory Cytokines and Suppressing Osteoclastogenesis

Biomedicines ◽  
2021 ◽  
Vol 9 (2) ◽  
pp. 199
Author(s):  
Urara Tanaka ◽  
Shunichi Kajioka ◽  
Livia S. Finoti ◽  
Daniela B. Palioto ◽  
Denis F. Kinane ◽  
...  
Keyword(s):  
Dna Methylation ◽  
Bone Resorption ◽  
Bone Loss ◽  
Inflammatory Cytokines ◽  
Osteoclast Differentiation ◽  
Tartrate Resistant Acid Phosphatase ◽  
Dependent Manner ◽  
Bone Homeostasis ◽  
Osteoblastic Cell Line ◽  
Anti Inflammatory

DNA methylation controls several inflammatory genes affecting bone homeostasis. Hitherto, inhibition of DNA methylation in vivo in the context of periodontitis and osteoclastogenesis has not been attempted. Ligature-induced periodontitis in C57BL/6J mice was induced by placing ligature for five days with Decitabine (5-aza-2′-deoxycytidine) (1 mg/kg/day) or vehicle treatment. We evaluated bone resorption, osteoclast differentiation by tartrate-resistant acid phosphatase (TRAP) and mRNA expression of anti-inflammatory molecules using cluster differentiation 14 positive (CD14+) monocytes from human peripheral blood. Our data showed that decitabine inhibited bone loss and osteoclast differentiation experimental periodontitis, and suppressed osteoclast CD14+ human monocytes; and conversely, that it increased bone mineralization in osteoblastic cell line MC3T3-E1 in a concentration-dependent manner. In addition to increasing IL10 (interleukin-10), TGFB (transforming growth factor beta-1) in CD14+ monocytes, decitabine upregulated KLF2 (Krüppel-like factor-2) expression. Overexpression of KLF2 protein enhanced the transcription of IL10 and TGFB. On the contrary, site-directed mutagenesis of KLF2 binding site in IL10 and TFGB abrogated luciferase activity in HEK293T cells. Decitabine reduces bone loss in a mouse model of periodontitis by inhibiting osteoclastogenesis through the upregulation of anti-inflammatory cytokines via KLF2 dependent mechanisms. DNA methyltransferase inhibitors merit further investigation as a possible novel therapy for periodontitis.

scholarly journals Estrogen Decreases Cytoskeletal Organization by Forming an ERα/SHP2/c-Src Complex in Osteoclasts to Protect against Ovariectomy-Induced Bone Loss in Mice

Antioxidants ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 619
Author(s):  
Hyun-Jung Park ◽  
Malihatosadat Gholam-Zadeh ◽  
Sun-Young Yoon ◽  
Jae-Hee Suh ◽  
Hye-Seon Choi
Keyword(s):  
Bone Resorption ◽  
Bone Loss ◽  
Ring Formation ◽  
Tartrate Resistant Acid Phosphatase ◽  
Actin Ring ◽  
Collagen Crosslinks ◽  
Trap Staining ◽  
Src Activation

Loss of ovarian function is closely related to estrogen (E2) deficiency, which is responsible for increased osteoclast (OC) differentiation and activity. We aimed to investigate the action mechanism of E2 to decrease bone resorption in OCs to protect from ovariectomy (OVX)-induced bone loss in mice. In vivo, tartrate-resistant acid phosphatase (TRAP) staining in femur and serum carboxy-terminal collagen crosslinks-1 (CTX-1) were analyzed upon E2 injection after OVX in mice. In vitro, OCs were analyzed by TRAP staining, actin ring formation, carboxymethylation, determination of reactive oxygen species (ROS) level, and immunoprecipitation coupled with Western blot. In vivo and in vitro, E2 decreased OC size more dramatically than OC number and Methyl-piperidino-pyrazole hydrate dihydrochloride (MPPD), an estrogen receptor alpha (ERα) antagonist, augmented the OC size. ERα was found in plasma membranes and E2/ERα signaling affected receptor activator of nuclear factor κB ligand (RANKL)-induced actin ring formation by rapidly decreasing a proto-oncogene tyrosine-protein kinase, cellular sarcoma (c-Src) (Y416) phosphorylation in OCs. E2 exposure decreased physical interactions between NADPH oxidase 1 (NOX1) and the oxidized form of c-Src homology 2 (SH2)-containing protein tyrosine phosphatase 2 (SHP2), leading to higher levels of reduced SHP2. ERα formed a complex with the reduced form of SHP2 and c-Src to decrease c-Src activation upon E2 exposure, which blocked a signal for actin ring formation by decreased Vav guanine nucleotide exchange factor 3 (Vav3) (p–Y) and Ras-related C3 botulinum toxin substrate 1 (Rac1) (GTP) activation in OCs. E2/ERα signals consistently inhibited bone resorption in vitro. In conclusion, our study suggests that E2-binding to ERα forms a complex with SHP2/c-Src to attenuate c-Src activation that was induced upon RANKL stimulation in a non-genomic manner, resulting in an impaired actin ring formation and reducing bone resorption.

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