Orthopedic Device Metallic and Calcium Phosphate Coatings: Testing and Characterization Requirements (DRAFT)
This guidance applies to Class II and Class III orthopedic devices with metallic and/or calcium phosphate coatings. It specifically covers: - Metallic coatings manufactured using thermal spray, sintering, vapor deposition, additive manufacturing or other methods - Calcium phosphate coatings manufactured by plasma spray, solution precipitation, electrochemical deposition or other methods - Dual coatings combining both metallic and calcium phosphate layers The guidance does not cover other types of coatings (ceramic, other calcium-based) or surface modifications (etching, anodizing). Drug/biologic characterization is also out of scope.
This is a draft guidance. Not for implementation.
Recommended Actions
- Determine if device requires clinical data based on novelty and risk assessment
- Develop comprehensive coating characterization plan including:
- Physical/chemical properties testing
- Mechanical integrity testing
- Biocompatibility evaluation
- Sterility validation
- Establish specifications and acceptance criteria for coating properties
- Validate shelf life and packaging system
- Prepare labeling with appropriate indications and limitations
- Determine if changes to existing devices require new 510(k) submission
- Consider pre-submission consultation for novel technologies or testing approaches
- Document all testing and validation in format suitable for regulatory submission
- Maintain design history file with complete test reports and justifications
- Monitor post-market performance to confirm coating safety and effectiveness
Key Considerations
Clinical testing
- Generally unnecessary except for novel technologies or when bench/animal testing raises concerns
- IDE requirements apply if clinical investigation is needed
- Real-world data may be acceptable in some cases
Non-clinical testing
- Coating description including name, method, materials, structure, location
- Mechanical testing for coating integrity and adhesion
- Microstructural characterization
- Chemical analysis and phase composition
- Dissolution rate testing for calcium phosphate coatings
- Substrate/device testing to evaluate coating process effects
Labelling
- Must specify cementless implantation for calcium phosphate coated joint arthroplasty
- Biological fixation claims only allowed for porous coatings meeting specific criteria
- “Nano” claims require supporting characterization data
Biocompatibility
- Required for all patient-contacting materials including substrate and coating
- Testing based on implant devices with tissue/bone contact and long-term duration
- Additional evaluation needed for novel coatings without predicate devices
Safety
- Sterility validation required
- Pyrogenicity testing needed
- Shelf life and packaging validation required
Other considerations
- Animal studies generally unnecessary except for novel technologies
- Changes requiring new 510(k): different coating method/vendor, additional layers, substrate material changes
- Changes not requiring new 510(k): material supplier changes within specs, reduced coating thickness within specs
Relevant Guidances
- Use of ISO 10993-1 for Biological Evaluation and Testing of Medical Devices
- Testing Requirements for Orthopedic Implants with Modified Metallic Bone-Interface Surfaces
- Recommended Format and Content for Non-Clinical Bench Performance Testing in Medical Device Premarket Submissions
- Content and Decision-Making Process for 510k Submissions: Determining Substantial Equivalence
- Deciding When to Submit a New 510k for Changes to an Existing Medical Device
Related references and norms
- ASTM F1854: Standard test method for stereological evaluation of porous coatings on medical implants
- ASTM F1147: Standard test method for tension testing of calcium phosphate and metallic coatings
- ASTM F1160: Standard test method for shear and bending fatigue testing of calcium phosphate and metallic coatings
- ASTM F1978: Standard test method for measuring abrasion resistance of metallic thermal spray coatings
- ISO 13779-1: Implants for surgery — Hydroxyapatite — Part 1: Ceramic hydroxyapatite
- ISO 13779-2: Implants for surgery — Hydroxyapatite — Part 2: Thermally sprayed coatings of hydroxyapatite
- ISO 11607-1: Packaging for terminally sterilized medical devices — Part 1: Requirements for materials, sterile barrier systems and packaging
- ISO 10993-1: Biological evaluation of medical devices — Part 1: Evaluation and testing within a risk management process
Original guidance
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