Testing of Non-Articulating, Mechanically Locked Modular Implant Components in Orthopedic Devices
This guidance provides recommendations for testing non-articulating, mechanically locked modular implant components in orthopedic devices, such as morse tapers, threaded interfaces, crimping mechanisms, and interference fits. It aims to help manufacturers provide necessary information to FDA for determining substantial equivalence and safety/effectiveness of these devices.
Recommended Actions
- Develop comprehensive material and design documentation
- Perform static and dynamic mechanical testing
- Conduct biocompatibility testing for new materials
- Execute wear, corrosion, and degradation studies
- Validate assembly/disassembly procedures
- Prepare detailed manufacturing process documentation
- Create clear labeling and surgical instructions
- Document all test results according to provided reporting format
- Collect and summarize available clinical data
- Validate test methods through in vitro/in vivo correlation
Key Considerations
Clinical testing
- Clinical data summary required for modified surfaces
- Information on loosening between device parts and bone-implant interface
- Documentation of surface coating failures and other success/failure indicators
Non-clinical testing
- Static strength testing for load to fracture and deformation
- Assembly/disassembly load measurements
- Device rigidity evaluation
- Stress analysis
- Fatigue testing
- Cyclic wear, degradation, and corrosion testing
- At least three identical test specimens and controls required
- Testing under physiological conditions (37°C, appropriate pH)
Human Factors
- Evaluation of ease of assembly by surgeon
- Evaluation of ease of disassembly by surgeon
- Assessment of risk of inadvertent disassembly in patient
Labelling
- Instructions for attachment and component matching required
- Clear identification of component compatibility
Biocompatibility
- Testing required for materials with limited clinical history
- ASTM F 748 and F 981 testing
- Animal implant model with particle introduction
- Histological examination of adjacent tissues and lymph nodes
Safety
- Evaluation of high induced stresses
- Assessment of thermal expansion effects during sterilization
- Analysis of material sufficiency to support loads
- Evaluation of stress risers
Other considerations
- Detailed material and design description required
- Manufacturing process documentation
- Comprehensive test reporting format provided
- Validation of test methods through comparison of in vitro to in vivo results
Relevant Guidances
- Testing Requirements for Orthopedic Implants with Modified Metallic Bone-Interface Surfaces
- Use of ISO 10993-1 for Biological Evaluation and Testing of Medical Devices
- Technical Considerations for Nitinol-Containing Medical Devices
- Non-Clinical Testing and Labeling Requirements for Femoral Stem Prostheses in Hip Replacement Systems
Related references and norms
- ASTM F 748: Standard Practice for Selecting Generic Biological Test Methods for Materials and Devices
- ASTM F 981: Standard Practice for Assessment of Compatibility of Biomaterials for Surgical Implants
- ASTM F 897: Standard Test Method for Measuring Fretting Corrosion of Osteosynthesis Plates and Screws
Original guidance
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