The History, Technical Specifications and Efficacy of Plasma Spray Coatings Applied to Joint Replacement Prostheses

McCabe, A.R.; Pickford, Martin; Shawcross, James

doi:10.15438/rr.6.4.136

Cited by 8 publications

(9 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Within the TPS process, Ti powder particles are melted by plasma, and the droplets are accelerated to the substrate where they solidify. This process results in a typical high surface roughness that improves bone anchorage [18]. The TPS coating exhibits an average roughness of 45 ± 15 μm (according to DIN EN ISO 4288) and a porosity of 20–40% (according to ASTM F 1854).…”

Section: Methodsmentioning

confidence: 99%

Glancing-Angle Deposition of Nanostructures on an Implant Material Surface

et al. 2019

View full text Add to dashboard Cite

Cell-compatible and antibacterial surfaces are needed for implants, which frequently have complex and rough surfaces. Bio-inspired columnar nanostructures can be grown on flat substrates; however, the application of these nanostructures on clinically relevant, complex, and rough surfaces was pending. Therefore, a titanium plasma spray (TPS) implant surface was coated with titanium nano-spikes via glancing angle magnetron sputter deposition (GLAD) at room temperature. Using GLAD, it was possible to cover the three-dimensional, highly structured macroscopic surface (including cavities, niches, clefts, and curved areas) of the TPS homogeneously with nano-spikes (TPS+), creating a cell-compatible and antibacterial surface. The adherence and spreading of mesenchymal stem cells (MSC) were similar for TPS and TPS+ surfaces. However, MSC adherent to TPS+ expressed less and shorter pseudopodia. The induced osteogenic response of MSC was significantly increased in cells cultivated on TPS+ compared with TPS. In addition, Gram-negative bacteria (E. coli) adherent to the nano-spikes were partly destructed by a physico-mechanical mechanism; however, Gram-positive bacteria (S. aureus) were not significantly damaged.

show abstract

Section: Methodsmentioning

confidence: 99%

Glancing-Angle Deposition of Nanostructures on an Implant Material Surface

et al. 2019

View full text Add to dashboard Cite

show abstract

“…To achieve the long-term stability of uncemented implants, either ingrowth or ongrowth of bone on the surface of the implant is necessary [ 3 ]. A certain porosity of the implant surface is needed for this to happen, which depends on the materials used and surface properties [ 3 , 4 , 5 , 6 , 7 ]. Porosity is obtained either by grit blasting the surface of the metal alloy or through addition of a coating [ 3 , 6 ].…”

Section: Introductionmentioning

confidence: 99%

“…A certain porosity of the implant surface is needed for this to happen, which depends on the materials used and surface properties [ 3 , 4 , 5 , 6 , 7 ]. Porosity is obtained either by grit blasting the surface of the metal alloy or through addition of a coating [ 3 , 6 ]. Most commonly, coatings either consisting of titanium or hydroxyapatite (HA) are applied by plasma-spray [ 3 , 6 ].…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

New Insights into Osteointegration and Delamination from a Multidisciplinary Investigation of a Failed Hydroxyapatite-Coated Hip Joint Replacement

et al. 2020

View full text Add to dashboard Cite

Hydroxyapatite (HA) coatings have become very popular in uncemented total hip arthroplasty (THA). Analysis of retrievals and tissue samples from an HA-coated femoral stem, which failed within 14 months after THA, provides exceptional insights into the failure mechanism, as well as the process of osteointegration of such an implant. Methods: Retrievals were photo-documented. Samples were examined by micro-computed tomography, X-ray diffraction (XRD) and embedded in polymethylmethacrylate for histology. Results: The coating had partially delaminated. The sandblasted surface of the stem was partially polished by the delaminated HA coating, indicating failure before revision. In the tissue samples, the HA coating was well integrated by newly formed bone trabeculae. No adverse biological reaction was observed. XRD analysis showed that residues of the HA coating were still present and could clearly be differentiated from the surrounding bone. Preferential orientation of the HA crystallites could be identified within the newly formed bone, representing a potential mechanical weakness induced either by physiologic strain or by the coating. Conclusion: current HA coatings, relatively thick and made of high crystallinity HA, may be prone to delamination, as also seen in our study. Recent efforts have aimed towards thinner (<1 μm) coatings with nanocrystalline HA structures that possibly relate to lower delamination risks. However, the question arises if HA coatings are beneficial since sandblasted non-coated stems offer similar results without the risk of delamination. XRD not only permits differentiation between the HA from the coating and the HA of the ongrown bone, it also provides new insights into the microstructure of this newly formed bone.

show abstract

“…Among various coating technologies (Ref 1), thermal spraying is one of the most commonly used and wellestablished techniques for coating medical devices and its major applications are within orthopedic and dental devices (Ref [3][4][5]. This article aims to help the thermal spray community to have a better understanding of the FDA premarket review process of thermal spray coatings on orthopedic medical devices, and the information that is important to submit in a marketing application as part of this process.…”

Section: Introductionmentioning

confidence: 99%

Thermal Spray Coatings on Orthopedic Devices: When and How the FDA Reviews Your Coatings

Sun

2018

J Therm Spray Tech

View full text Add to dashboard Cite

Thermal spray coatings have been commonly applied on medical devices for various reasons, e.g., surface roughening, biological fixation, and similarity of chemical composition to bone minerals. Generally, to introduce a thermal spray-coated device to the US market, a premarket review of the coated device is necessary by the US Food and Drug Administration (FDA). This article aims to improve understanding regarding FDA review of thermal spray coatings in orthopedic medical device marketing applications and expectations for information to be submitted as part of this process. While different thermal spray technologies and materials have been used for coatings on medical devices, thermal spray coatings often seen by the FDA on orthopedic devices include plasma-sprayed titanium (Ti) coatings and hydroxyapatite (HA) coatings as well as Ti/HA dual coatings. The coated devices are mostly metals (e.g., Ti alloy, cobalt-chromium alloy, stainless steel alloys) and some polymers (e.g., polyetheretherketone). The FDA does not clear or approve individual coatings or materials; rather, coatings and materials are evaluated as part of the final, finished medical device in the context of the specific device technological characteristics and intended use. The FDA has two current guidance documents for orthopedic implants with modified metallic surfaces and hydroxyapatite coatings, which outline the FDA's recommendations for full characterization and testing of these two types of coatings, respectively. Additionally, the standards organizations (e.g., ISO and ASTM) have developed many materials and testing standards for these coatings, some of which are recognized by the FDA. It is helpful that the coating companies reference these standards for appropriate material/coating specifications, testing methods, and acceptance criteria. Depending on the intended use of the coated device, it is important that coating properties also address some items specific to that device type. Additionally, the impact of cleaning, sterilization, and packaging/shelf-life processes on the coating properties is also considered to ensure that the coated device is safe for its intended use. Keywords hydroxyapatite (HA) coating Á ISO and ASTM standard Á medical device Á plasma spray Á premarket review Á titanium (Ti) coating Á US Food and Drug Administration (FDA) guidance Neither Dr. Sun nor a member of Dr. Sun's immediate family has received anything of value from or owns stock in a commercial company or institution related directly or indirectly to the subject of this article. No official support or endorsement of this article by the US Food and Drug Administration (FDA) is intended or should be inferred. The views presented in this article do not necessarily reflect those of the FDA. The findings and conclusions in this article should not be construed to represent any FDA determination, guidance, or policy.

show abstract

The History, Technical Specifications and Efficacy of Plasma Spray Coatings Applied to Joint Replacement Prostheses

Cited by 8 publications

References 0 publications

Glancing-Angle Deposition of Nanostructures on an Implant Material Surface

Glancing-Angle Deposition of Nanostructures on an Implant Material Surface

New Insights into Osteointegration and Delamination from a Multidisciplinary Investigation of a Failed Hydroxyapatite-Coated Hip Joint Replacement

Thermal Spray Coatings on Orthopedic Devices: When and How the FDA Reviews Your Coatings

Contact Info

Product

Resources

About