Technical Considerations for Non-Spinal Metallic and Polymer Bone Plates and Screws
This guidance document covers class II, orthopedic, non-resorbable, non-spinal bone plate and screw systems, stand-alone bone screws, and associated washers regulated under 21 CFR 888.3030 and 21 CFR 888.3040. It specifically addresses devices made from common metallic materials (titanium alloys, stainless steel, cobalt-chrome) and polymers (PEEK, CFR PEEK). The guidance excludes devices for spinal, mandibular, maxillofacial, cranial and orbital applications, as well as devices with unique characteristics like nitinol materials, coatings, antimicrobial agents, or additive manufacturing.
What You Need to Know? 👇
What are the key material requirements for orthopedic non-spinal bone plates and screws?
Devices must be made from non-resorbable materials conforming to FDA-recognized standards like ASTM F136 for titanium alloy, ASTM F138 for stainless steel, or ASTM F1537 for cobalt-chrome alloy. PEEK and carbon fiber reinforced PEEK are also acceptable per relevant ASTM specifications.
Which mechanical tests are required for bone plate 510(k) submissions?
Single cycle bend testing per ASTM F382 is required for the worst-case plate design. Testing should evaluate bending structural stiffness and bending strength in the structurally critical region. Fatigue testing may be needed for devices with novel technological characteristics.
What screw performance testing must be included in the submission?
Three key tests per ASTM F543: insertion/removal torque testing, torsional strength testing, and pullout strength testing. These should be conducted on worst-case screw designs considering parameters like diameter, thread pitch, and polar moment of inertia.
Are clinical studies typically required for these orthopedic devices?
No, clinical studies are generally unnecessary for most bone plates and screws. They may be requested only for devices with dissimilar indications, new technology, or when engineering testing raises safety concerns requiring further clinical evaluation.
What biocompatibility endpoints must be addressed for permanent implants?
For bone plates, screws, and washers (permanent tissue/bone contact), address: cytotoxicity, sensitization, irritation, acute systemic toxicity, material-mediated pyrogenicity, subacute/subchronic toxicity, genotoxicity, implantation, chronic toxicity, and carcinogenicity per ISO 10993-1.
When is a new 510(k) required for device modifications?
A new 510(k) is required for changes that could significantly affect safety or effectiveness, such as: adding thinner plates or screws with lower pullout strength, changing sterilization methods, material changes, or modifying system component compatibility.
What You Need to Do 👇
Recommended Actions
- Determine worst-case device configurations for testing based on dimensions and design features
- Conduct required mechanical testing:
- Plate bending tests
- Screw insertion/removal torque
- Screw torsional strength
- Screw pullout strength
- Complete biocompatibility evaluation for all patient-contacting materials
- Validate sterilization process if provided sterile
- Validate reprocessing instructions if reusable
- Develop comprehensive labeling including all required elements
- Evaluate and document MR compatibility
- Validate packaging and shelf life if provided sterile
- Consider submitting a Pre-Submission to FDA for feedback if device has unique characteristics not covered by guidance
- Prepare 510(k) submission including all test reports, validations, and required documentation
Key Considerations
Clinical testing
- Generally unnecessary for most bone plates and screws
- May be required for:
- Indications dissimilar from legally marketed devices
- New technology different from legally marketed devices
- Cases where engineering/animal testing raises issues needing clinical evaluation
Non-clinical testing
- Mechanical performance testing required for plates:
- Single cycle bend testing per ASTM F382
- Fatigue testing may be needed for devices with different technological features
- Mechanical performance testing required for screws:
- Insertion/removal torque testing per ASTM F543
- Torsional strength testing per ASTM F543
- Pullout strength testing per ASTM F543
Labeling
- Must include:
- Device description (material, sterility status)
- Device use (single-use/reusable, intended users/populations)
- Contraindications
- Warnings
- MR safety information
- Cleaning/sterilization instructions if applicable
- Removal instructions when appropriate
Biocompatibility
Must address following endpoints for implants:
- Cytotoxicity
- Sensitization
- Irritation/intracutaneous reactivity
- Acute systemic toxicity
- Material mediated pyrogenicity
- Subacute/subchronic toxicity
- Genotoxicity
- Implantation
- Chronic toxicity
- Carcinogenicity
Safety
- Must address MR safety and compatibility
- Must address pyrogenicity for sterile devices
- Must validate shelf life and packaging integrity
Other considerations
- Sterilization validation required for sterile devices
- Reprocessing validation required for reusable instruments
- Engineering analysis can be used in lieu of some mechanical testing with proper justification
Relevant Guidances 🔗
- Use of ISO 10993-1 for Biological Evaluation and Testing of Medical Devices
- Testing and Labeling of Medical Devices for Magnetic Resonance (MR) Environment Safety and Compatibility
- Reprocessing Instructions for Reusable Medical Devices and Non-Sterile Single-Use Devices - Development and Validation
- Submission Requirements for Terminally Sterilized Medical Devices
- Q-Submission Program: Strategic Framework for FDA Interactions in Medical Device Development
Related references and norms 📂
- ASTM F382: Standard Specification and Test Method for Metallic Bone Plates
- ASTM F543: Standard Specification and Test Methods for Metallic Medical Bone Screws
- ASTM F1839: Standard Specification for Rigid Polyurethane Foam for Use as a Standard Material for Testing Orthopaedic Devices and Instruments
- ISO 11607-1: Packaging for terminally sterilized medical devices – Part 1: Requirements for materials, sterile barrier systems and packaging systems
- ISO 11607-2: Packaging for terminally sterilized medical devices – Part 2: Validation requirements for forming, sealing and assembly processes
- ASTM F1980: Standard Guide for Accelerated Aging of Sterile Barrier Systems for Medical Devices