Overview
ISO 22926:2023 - Implants for surgery: Specification and verification of synthetic anatomical bone models for testing defines requirements and recommendations for specifying, verifying and reporting synthetic anatomical bone models used in implant testing. The standard focuses on 3D shape and mechanical characteristics (not cosmetic features). Digital anatomical sources can include CT scans, cadaveric-derived data or statistically determined shape datasets that are used to produce physical synthetic models via casting, machining or additive manufacturing.
Key technical topics and requirements
- Scope and focus
- Covers specification and verification of synthetic bone models for implant testing.
- Excludes colour and cosmetic characteristics.
- Digital and physical models
- Defines a digital anatomical bone model (STL, CAD/STEP, voxel models) and the resulting synthetic anatomical bone model.
- Required physical model characteristics
- 3D overall shape and segmented anatomy (e.g., cortical, cancellous, intramedullary canal).
- Material properties: density, hardness, porosity, Young’s modulus, surface roughness.
- Structural mechanical characteristics: stiffness, ultimate strength, fatigue strength under specified loading.
- Other relevant characteristics: thermal/chemical resistance, residual stress, dimensional stability, fluid absorption.
- Verification process
- Three-step verification: model geometrical verification, model material verification, and model mechanical verification (when required).
- Geometrical verification requires comparison to the digital model and consideration of measurement protocol, device and software errors (fiducial points, registration variability).
- Material and mechanical verifications are compared to the specified properties and reported.
- Traceability and reporting
- Producers must ensure traceability through design and manufacturing.
- A specification report must document intended use, geometry, measurement methods and protocols, test results (mean, max, deviations), material tests and any limitations or contraindications. Annex C provides an example report; Annex B gives geometrical verification examples.
Practical applications
- Standardizes how synthetic bone models are specified and verified for:
- Mechanical testing of orthopaedic implants and fixation constructs (stiffness, strength, fatigue).
- Preclinical device development, bench testing and comparative performance studies.
- Verification of manufacturing processes for medical device test fixtures and surgical tool validation.
- Helps users choose models with appropriate anatomical fidelity and mechanical behavior for their specific implant tests.
Who should use this standard
- Synthetic bone model producers and manufacturers
- Medical device developers and test engineers
- Biomechanics laboratories and notified bodies
- Regulatory and quality teams preparing test evidence for implants
- Research groups conducting implant or surgical tool evaluation
Related standards
- ISO 19213 - Test methods for synthetic cortical bone materials (referenced for material testing)
- ASTM F1839 - Specification for rigid polyurethane foam (material commonly used as cancellous bone analogue)
Keywords: ISO 22926, synthetic anatomical bone models, implant testing, 3D shape verification, model material verification, geometrical verification, specification report, CT-based bone models.
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