Effect of Bioactive Grade Surface on In Vivo Behavior and Mechanical Stability in Titanium Based Implant Surface-Modified by Plasma Spray Coating and Chemical Treatments

2004 ◽  
Vol 449-452 ◽  
pp. 1221-1224
Author(s):  
Baek Hee Lee ◽  
Young Do Kim ◽  
Kyu Hwan Lee
Keyword(s):  
Mechanical Stability ◽  
Testing Machine ◽  
Spray Coating ◽  
Implant Surface ◽  
Chemical Treatments ◽  
Pull Out ◽  
Living Bone ◽  
Surface Modified ◽  
Pull Out Strength

Geometrical and chemical designs of an implant surface affected the stabilization of implant and the healing of tissue. In this study, effects of surface designs in implants on in vivo behavior and mechanical stability were compared by histological and mechanical analyses. The implants were transversely grafted on dog thighbone and healed for 4 and 8 weeks. The pull-out strength between living bone and implant was evaluated by universal testing machine (UTM).

scholarly journals Optimizing Manufacturing and Osseointegration of Ti6Al4V Implants through Precision Casting and Calcium and Phosphorus Ion Implantation? In Vivo Results of a Large-Scale Animal Trial

Materials ◽  
2020 ◽  
Vol 13 (7) ◽  
pp. 1670 ◽  
Author(s):  
Wölfle-Roos JV ◽  
Katmer Amet B ◽  
Fiedler J ◽  
Michels H ◽  
Kappelt G ◽  
...  
Keyword(s):  
Ion Implantation ◽  
Large Scale ◽  
In Vivo Studies ◽  
Control Group ◽  
Implant Surface ◽  
Precision Casting ◽  
Pull Out ◽  
Significant Difference ◽  
Calcium And Phosphorus

Background: Uncemented implants are still associated with several major challenges, especially with regard to their manufacturing and their osseointegration. In this study, a novel manufacturing technique—an optimized form of precision casting—and a novel surface modification to promote osseointegration—calcium and phosphorus ion implantation into the implant surface—were tested in vivo. Methods: Cylindrical Ti6Al4V implants were inserted bilaterally into the tibia of 110 rats. We compared two generations of cast Ti6Al4V implants (CAST 1st GEN, n = 22, and CAST 2nd GEN, n = 22) as well as cast 2nd GEN Ti6Al4V implants with calcium (CAST + CA, n = 22) and phosphorus (CAST + P, n = 22) ion implantation to standard machined Ti6Al4V implants (control, n = 22). After 4 and 12 weeks, maximal pull-out force and bone-to-implant contact rate (BIC) were measured and compared between all five groups. Results: There was no significant difference between all five groups after 4 weeks or 12 weeks with regard to pull-out force (p > 0.05, Kruskal Wallis test). Histomorphometric analysis showed no significant difference of BIC after 4 weeks (p > 0.05, Kruskal–Wallis test), whereas there was a trend towards a higher BIC in the CAST + P group (54.8% ± 15.2%), especially compared to the control group (38.6% ± 12.8%) after 12 weeks (p = 0.053, Kruskal–Wallis test). Conclusion: In this study, we found no indication of inferiority of Ti6Al4V implants cast with the optimized centrifugal precision casting technique of the second generation compared to standard Ti6Al4V implants. As the employed manufacturing process holds considerable economic potential, mainly due to a significantly decreased material demand per implant by casting near net-shape instead of milling away most of the starting ingot, its application in manufacturing uncemented implants seems promising. However, no significant advantages of calcium or phosphorus ion implantation could be observed in this study. Due to the promising results of ion implantation in previous in vitro and in vivo studies, further in vivo studies with different ion implantation conditions should be considered.

A Novel Technique for Measuring Pedicle Screw Forces In Situ

2008 ◽  
Author(s):  
Samuel Q. Tia ◽  
Jennifer M. Buckley ◽  
Thuc-Quyen Nguyen ◽  
Jeffrey C. Lotz ◽  
Shane Burch
Keyword(s):  
Pedicle Screw ◽  
Pedicle Screws ◽  
Clinical Failure ◽  
Strain Gages ◽  
Destructive Testing ◽  
Novel Technique ◽  
Pull Out ◽  
Pull Out Strength

Long posterior fusion constructs in the lumbar spine cause substantial posteriorly directed loading of the supporting pedicle screws, particularly during patient bending activities. Although there are numerous documented accounts of clinical failure at the pedicle screw-bone interface [1,2], the in situ pull-out strength of pedicle screws in long surgical constructs has not been characterized. Previous biomechanical studies have quantified pedicle screw pull-out force in cadaveric models through destructive testing or in nondestructive cases, through the use of custom-machined pedicle screws instrumented with strain gages [3–6]. However, these techniques involve altering screw geometry and may fail to properly simulate in vivo mechanical loading conditions. The goal of this study was to develop and validate a sensor system for measuring pedicle screw pull-out forces in long posterior constructs in situ during multi-segmental cadaveric testing.

Axial pull-out strength of 3.5 cortical and 4.0 cancellous bone screws placed in canine proximal tibias using manual and power tapping

2008 ◽  
Vol 21 (04) ◽  
pp. 323-328 ◽  
Author(s):  
M. E. Soniat ◽  
S. Elder ◽  
R. McLaughlin ◽  
J. L. Demko
Keyword(s):  
Cancellous Bone ◽  
Testing Machine ◽  
Bone Screws ◽  
Materials Testing ◽  
Pull Out ◽  
Cortical Width ◽  
Bone Width ◽  
Significant Difference ◽  
Pull Out Strength

SummaryAn in vitro experimental cadaveric mechanical testing study was performed using 20 radiographically mature dogs, weighing between 18–33 kg. The aim of the study was to compare the axial pull-out strength of 3.5 mm cortical and 4.0 mm cancellous bone screws inserted in the canine proximal tibia using manual and power tapping techniques. 3.5 cortical and 4.0 cancellous bone screws were inserted in canine cadaver proximal tibiae using a manual or power tapping technique. The screws were extracted using a servohydraulic materials testing machine in order to measure axial pullout strength. Axial pull-out strength was recorded relative to the total bone width and total cortical width of each tibia. The mean axial pull-out strength for all constructs was 717.8±56.5 N without any statistically significant difference among groups (p=0.4183). The groups were equal in animal body weight, cortical width and total bone width (p=0.2808). The axial pull-out strength in proportion to cortical and total bone width was not significantly different among groups (p=0.5318). Axial pull-out strengths of 3.5 mm cortical and 4.0 mm cancellous bone screws inserted in the proximal tibial metaphysis were not significantly different. Axial pull-out strength was not affected by the use of power tapping in either screw type.

Comparative Experimental Study of Hook and Pedicle Fixation Systems Used at Surgical Treatment of Spine Deformities

2012 ◽  
Vol 19 (3) ◽  
pp. 20-24 ◽  
Author(s):  
A. A Kuleshov ◽  
I. N Lisyansky ◽  
M. S Vetrile ◽  
N. S Gavryushenko ◽  
L. V Fomin
Keyword(s):  
Static Load ◽  
Testing Machine ◽  
Pedicle Screws ◽  
Cyclic Loads ◽  
Pedicle Fixation ◽  
Pull Out ◽  
Spine Deformities ◽  
Laminar Hooks ◽  
Vertebral Arch ◽  
Pull Out Strength

Using human cadaver spines we compared the stiffness of pedicle screws and laminar hooks under cyclic and static pull-out loads. Transpedicular and hook fixation (sub- and supralaminar) of cadaveric thoracic spine segments was performed. Axial pull-out strength was measured using w+b (walter + bai ag) servoelectric testing machine (LFV-10-T50, Switzerland). Static pull-out tests were performed on 7 spine blocks with transpedicular and 7 blocks with hook fixation. The same blocks were tested under cyclic loads. At cyclic pull-out loading 800 N strength with 5 Hz frequency was applied. It was shown that at increasing static load hook implants could bear 1417 N at average. At higher loads the vertebral arch was destroyed. Transpedicular implants could bear 2286 N at average and at higher loads the screw migrated from the arch root. Cyclic tests showed that hooks could bear 2935 cycles at average and at prolonged loading the arch was destroyed. The hooks could bear the full; program of cyclic loads without destruction (18 000 cycles).

scholarly journals Sustainable Surface Modification of Polyetheretherketone (PEEK) Implants by Hydroxyapatite/Silica Coating—An In Vivo Animal Study

Materials ◽  
2021 ◽  
Vol 14 (16) ◽  
pp. 4589
Author(s):  
Thomas Frankenberger ◽  
Constantin Leon Graw ◽  
Nadja Engel ◽  
Thomas Gerber ◽  
Bernhard Frerich ◽  
...  
Keyword(s):  
Bone Formation ◽  
Fibrous Tissue ◽  
Composite Layer ◽  
Silica Coating ◽  
Silica Matrix ◽  
Biological Behavior ◽  
Implant Surface ◽  
Adult Rats ◽  
Pull Out

Polyetheretherketone (PEEK) has the potential to overcome some of the disadvantages of titanium interbody implants in anterior cervical and discectomy and fusion (ACDF). However, PEEK shows an inferior biological behavior regarding osseointegration and bioactivity. Therefore, the aim of the study was to create a bioactive surface coating on PEEK implants with a unique nanopore structure enabling the generation of a long-lasting interfacial composite layer between coating material and implant. Seventy-two PEEK implants—each thirty-six pure PEEK implants (PI) and thirty-six PEEK implants with a sprayed coating consisting of nanocrystalline hydroxyapatite (ncHA) embedded in a silica matrix and interfacial composite layer (SPI)—were inserted in the femoral condyles of adult rats using a split-side model. After 2, 4 and 8 weeks, the femur bones were harvested. Half of the femur bones were used in histological and histomorphometrical analyses. Additionally, pull-out tests were performed in the second half. Postoperative healing was uneventful for all animals, and no postoperative complications were observed. Considerable crestal and medullary bone remodeling could be found around all implants, with faster bone formation around the SPI and fewer regions with fibrous tissue barriers between implant and bone. Histomorphometrical analyses showed a higher bone to implant contact (BIC) in SPI after 4 and 8 weeks (p < 0.05). Pull-out tests revealed higher pull-out forces in SPI at all time points (p < 0.01). The presented findings demonstrate that a combination of a bioactive coating and the permanent chemical and structural modified interfacial composite layer can improve bone formation at the implant surface by creating a sustainable bone-implant interface. This might be a promising way to overcome the bioinert surface property of PEEK-based implants.

scholarly journals Comparison of Initial Stability of Oblong, Large Circular, and Multiple-Plug “Snowman” Osteochondral Autografts for Elongated Focal Cartilage Lesions: A Biomechanical Study in a Porcine Model

2021 ◽  
Vol 9 (11) ◽  
pp. 232596712110449
Author(s):  
Shashank Dwivedi ◽  
Michael Kutschke ◽  
Maheen Nadeem ◽  
Brett D. Owens
Keyword(s):  
Clinical Outcomes ◽  
Maximum Load ◽  
Biomechanical Study ◽  
Osteochondral Allograft ◽  
Osteochondral Lesions ◽  
Pull Out ◽  
Initial Stability ◽  
Significant Difference ◽  
Pull Out Strength

Background: Distal femoral osteochondral allograft transplantation (OAT) is an effective treatment of osteochondral lesions in the knee measuring >2 cm2 in select patients. Prior studies have demonstrated that the morphology of the plug can affect graft-host interference fit. To our knowledge, there are no data comparing the initial biomechanical stability of standard cylindrical plugs with multiple-plug and oblong-plug morphologies. Hypothesis: Large cylindrical single-plug (LCSP) and oblong single-plug (OSP) grafts will have greater pull-out strength, and therefore greater initial stability, than multiple-plug (MP) grafts in a cadaveric porcine femur model. Study Design: Controlled laboratory study. Methods: A total of 55 porcine distal femurs were divided into 3 groups—LCSP (n = 18), OSP (n = 19), and MP (n = 18)—according to the plug morphology used. The method of graft harvesting and implantation was based on technique guides for the respective implant systems. The sizes (length × width × depth) of the osteochondral defects created in each of the groups were approximately 20.2 × 20.2 × 9.4–mm for the LCSP group, 14.4 × 30.5 × 7.9–mm for the OSP group, and 14.8 × 14.8 × 9.9–mm for the MP group. Tensile testing was performed on each graft to determine pull-out strength. Results: The pull-out strength was significantly lower in the OSP group (65.7 N) versus the LCSP (133 N; P = .0005) and the MP (117.6 N; P = .001) groups. There was no statistically significant difference in pull-out strength between the LCSP and MP groups ( P = .42). There were no statistically significant differences in displacement at maximum load among any 2 of the 3 groups. Conclusion: These findings suggest that while initial stability may play a role in the clinical outcomes of osteochondral allograft (OCA) implantation, the biological milieu in vivo for each graft setting perhaps has a greater impact on the success of an OAT procedure. Further study is needed on the relationship between OCA biomechanics and clinical outcomes of OAT.

Effect of Micro-Grooving on the Stress Shielding of Titanium: Experimental and Numerical Investigations

2017 ◽  
Author(s):  
Harsha G. Jamadagni ◽  
Hasan Karaman ◽  
Fatih Karpat ◽  
Wendy Williams ◽  
Lokesh Dhanasekaran ◽  
...  
Keyword(s):  
Mechanical Stability ◽  
Equivalent Stress ◽  
Rabbit Model ◽  
Frictional Coefficient ◽  
Stress Shielding ◽  
Test Model ◽  
Implant Surface ◽  
Fea Model ◽  
Pull Out ◽  
Micro Grooving

Micron sizes grooves can control the cell settlement on the implant surface or be used to direct tissue generation at the implant/bone interface. The effect of shape, size and the type of material of the microgrooves on the mechanical stimulus transfer from the implant to bone at physiological loading is not known yet. Therefore, this study evaluated both experimentally and numerically the effect of surface modification on a titanium implant to the load transfer characteristics from implant to bone for examining stress shielding parameters. This study measured the effect of micron grooves on titanium to the mechanical stability of titanium using a rabbit model. This study also developed a finite element model based on the in vivo test model to examine the stress shielding parameters. The results showed that the mean values of fracture strength were significantly higher for grooved titanium samples (1.32±0.45 MPa, n = 3) compared to control samples (without any groove) (0.22±0.16 MPa, n = 6) (P < 0.05). The load-displacement graph from the pull out tension tests was used to measure the frictional coefficient between Ti and bone from the FEA model. It was found from the FEA model that the average co-efficient of friction between titanium and bone was 0.50. Maximum equivalent stress along the interface of microgrooves on titanium was higher from groove area in compare to the non-groove area because of the change of the geometry along the groove. The microgrooves in the model have a significant effect on the stress transfer parameter between implant and adjoining bone. The unequal load sharing due to micro-grooving causes an increase in stiffness of the adjacent bone to the implant.

scholarly journals Gluing Living Bone Using a Biomimetic Bioadhesive: From Initial Cut to Final Healing

2021 ◽  
Vol 9 ◽  
Author(s):  
Philip Procter ◽  
Gry Hulsart-Billström ◽  
Antoine Alves ◽  
Michael Pujari-Palmer ◽  
David Wenner ◽  
...  
Keyword(s):  
Osteoporotic Fractures ◽  
Abrupt Increase ◽  
New Methods ◽  
Pull Out ◽  
Ectopic Bone ◽  
Living Bone ◽  
The Mean ◽  
Reoperation Rates ◽  
Normal Bone Tissue

Osteoporotic fractures are a growing issue due to the increasing incidence of osteoporosis worldwide. High reoperation rates in osteoporotic fractures call for investigation into new methods in improving fixation of osteoporotic bones. In the present study, the strength of a recently developed bone bioadhesive, OsStictm, was evaluated in vivo using a novel bone core assay in a murine animal model at 0, 3, 7, 14, 28, and 42 days. Histology and micro-CT were obtained at all time points, and the mean peak pull-out force was assessed on days 0–28. The adhesive provided immediate fixation to the bone core. The mean peak bone core pull-out force gradually decreased from 6.09 N (σ 1.77 N) at day 0 to a minimum of 3.09 N (σ 1.08 N) at day 7, recovering to 6.37 N (σ 4.18 N) by day 28. The corresponding fibrin (Tisseel) control mean peak bone core pull-out characteristic was 0.27 N (σ 0.27 N) at day 0, with an abrupt increase from 0.37 N (σ 0.28) at day 3, 6.39 N (σ 5.09 N) at day 7, and continuing to increase to 11.34 N (σ 6.5 N) by day 28. The bone cores failed either through core pull-out or by the cancellous part of the core fracturing. Overall, the adhesive does not interrupt healing with pathological changes or rapid resorption. Initially, the adhesive bonded the bone core to the femur, and over time, the adhesive was replaced by a vascularised bone of equivalent quality and quantity to the original bone. At the 42 day time point, 70% of the adhesive in the cancellous compartment and 50% in the cortical compartment had been replaced. The adhesive outwith the bone shell was metabolized by cells that are only removing the material excess with no ectopic bone formation. It is concluded that the adhesive is not a physical and biochemical barrier as the bone heals through the adhesive and is replaced by a normal bone tissue. This adhesive composition meets many of the clinical unmet needs expressed in the literature, and may, after further preclinical assessments, have potential in the repair of bone and osteochondral fragments.

scholarly journals MXene in the lens of biomedical engineering: synthesis, applications and future outlook

2021 ◽  
Vol 20 (1) ◽  
Author(s):  
Adibah Zamhuri ◽  
Gim Pao Lim ◽  
Nyuk Ling Ma ◽  
Kian Sek Tee ◽  
Chin Fhong Soon
Keyword(s):  
Biomedical Engineering ◽  
Mechanical Stability ◽  
Drug Loading ◽  
High Surface ◽  
High Surface Area ◽  
Biological Properties ◽  
Tantalum Carbide ◽  
Biological Tool ◽  
Surface Modified

AbstractMXene is a recently emerged multifaceted two-dimensional (2D) material that is made up of surface-modified carbide, providing its flexibility and variable composition. They consist of layers of early transition metals (M), interleaved with n layers of carbon or nitrogen (denoted as X) and terminated with surface functional groups (denoted as Tx/Tz) with a general formula of Mn+1XnTx, where n = 1–3. In general, MXenes possess an exclusive combination of properties, which include, high electrical conductivity, good mechanical stability, and excellent optical properties. MXenes also exhibit good biological properties, with high surface area for drug loading/delivery, good hydrophilicity for biocompatibility, and other electronic-related properties for computed tomography (CT) scans and magnetic resonance imaging (MRI). Due to the attractive physicochemical and biocompatibility properties, the novel 2D materials have enticed an uprising research interest for application in biomedicine and biotechnology. Although some potential applications of MXenes in biomedicine have been explored recently, the types of MXene applied in the perspective of biomedical engineering and biomedicine are limited to a few, titanium carbide and tantalum carbide families of MXenes. This review paper aims to provide an overview of the structural organization of MXenes, different top-down and bottom-up approaches for synthesis of MXenes, whether they are fluorine-based or fluorine-free etching methods to produce biocompatible MXenes. MXenes can be further modified to enhance the biodegradability and reduce the cytotoxicity of the material for biosensing, cancer theranostics, drug delivery and bio-imaging applications. The antimicrobial activity of MXene and the mechanism of MXenes in damaging the cell membrane were also discussed. Some challenges for in vivo applications, pitfalls, and future outlooks for the deployment of MXene in biomedical devices were demystified. Overall, this review puts into perspective the current advancements and prospects of MXenes in realizing this 2D nanomaterial as a versatile biological tool.

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