Catalog of Regulatory Science Tools to Help Assess New Medical Devices
This regulatory science tool (RST) is a coupon designed for use in tensile testing additively manufactured lattices.
Technical Description
This RST is a lattice coupon design, considerations for applying the user’s lattice structure to the coupon, and example design files showing different lattice structures incorporated into the tensile coupon design. This tensile coupon is a pin loaded design which makes it compatible with most mechanical load frame systems. The coupon can incorporate a range of lattice designs with simple Boolean operations by the end user. These tensile coupons are intended to be applicable to both metal and polymer materials.
Intended Purpose
The intended purpose of this RST is to provide an AM lattice tensile coupon design that can differentiate between different lattice types. A review of FDA cleared AM devices showed that two-thirds of cleared implants incorporated a lattice structure [1] which have included procodes MAX (intervertebral fusion device with bone graft, lumbar), LPH (prosthesis, hip, semi-constrained, metal/polymer, porous uncemented), KWS (prosthesis, shoulder, semi-constrained, metal/polymer cemented), MBH (prosthesis, knee, patello/femorotibial, semi-constrained, uncemented, porous, coated, polymer/metal/polymer), and JWH (prosthesis, knee, patellofemorotibial, semi-constrained, cemented, polymer/metal/polymer). These tensile test coupons are intended to be used to evaluate lattice mechanical performance and differentiate between lattice designs.
Testing
The RST was evaluated using published data on tensile coupons of nylon (PA2200 – Polyamide 12) [2] and titanium alloy (Ti-6Al-4V) [3].
In the first publication, this AM lattice tensile coupon was used to study a regular and irregular lattice at different relative densities made from nylon. In the second publication, this AM lattice coupon was used to study regular lattices made from titanium alloy. In both publications, the lattice coupon was able to differentiate between lattice designs.
Limitations
This RST has only been evaluated for the materials mentioned in the Testing section and may be challenged if used with materials outside these bounds. Additional limitations are discussed in the published manuscripts. This tool does not limit the type of lattice tested using this coupon.
Supporting Documentation
[1] Laura M. Ricles et al. “Regulating 3D-printed medical products.” Sci. Transl. Med.10,eaan6521(2018)
[2] Porter, Daniel A., et al. "Nylon lattice design parameter effects on additively manufactured structural performance." Journal of the Mechanical Behavior of Biomedical Materials 125 (2022): 104869.
[3] Papazoglou, Dimitri P., et al. "Compression and Tensile Testing of L-PBF Ti-6Al-4V Lattice Structures with Biomimetic Porosities and Strut Geometries for Orthopedic Implants." Metals 14.2 (2024): 232.
Contact
Tool Reference
- RST Reference Number: RST26OP07.01
- Date of Publication: 05/05/2026
- Recommended Citation: U.S. Food and Drug Administration. (2026). Additively Manufactured Coupon for Characterizing Mechanical Performance of a Lattice in Tension (RST26OP07.01). https://cdrh-rst.fda.gov/additively-manufactured-coupon-characterizing-mechanical-performance-lattice-tension