This specification describes the compositional requirements, physical requirements, mechanical requirements, and test methods for rigid unicellular polyurethane foam for use in testing orthopaedic devices or instruments.

This foam described in this specification is not intended to replicate the mechanical properties of human or animal bone. The requirements of this specification are intended to provide a consistent and uniform material with properties on the order of human cancellous bone to use as a test medium when testing various orthopaedic devices, such as bone screws.

This specification covers rigid polyurethane foam blocks or sheets recommended for use as a standard material for mechanical testing using orthopedic devices and instruments. Although the physical properties of the foam are in the order of those reported for human cancellous bones, these materials are not intended for implantation into the human body. All materials should conform to the specified quality of appearance, dimensional stability, and composition, and values of void content, compressive strength, compressive modulus, shear strength, shear modulus, and screw pullout.

1.1 This specification covers rigid unicellular polyurethane foam for use as a standard material for performing mechanical tests utilizing orthopaedic devices or instruments. The specification is applicable to sheets or blocks of foam, or foam that is made by the user using a two-part liquid mixture.

1.2 This specification covers polyurethane foam material that is used in the laboratory for mechanical testing, as described in 1.1. These materials are not intended for implantation into the human body.

1.3 The foam described herein possesses mechanical properties which are on the order of those reported for human cancellous bone. See Appendix X1 Rationale for further information regarding the appropriateness of using the specified foam as a model for human cancellous bone.

1.4 This specification covers compositional requirements, physical requirements, mechanical requirements, and test methods for rigid polyurethane foam in the solid final form.

1.5 This specification provides qualification criteria for vendor or end-user processes and acceptance criteria for individual material lots.

1.6 This specification provides mechanical properties of five different grades of foam in the solid final form. A foam that does not meet the specified mechanical properties shall be identified as an ungraded foam.

1.7 Unless otherwise indicated, the values stated in SI units are to be regarded as standard. The values in parentheses are mathematical conversions to inch-pound units that are provided for information only and are not considered standard.

1.8 The following precautionary statement pertains to the test method portion only, Section 8, of this specification: This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.