ASTM F2502-17 Standard Specification and Test Methods for Absorbable Plates and Screws for Internal Fixation Implants

The standard "ASTM F2502-17 Standard specification and test methods for absorbable plates and screws for internal fixation implants" developed by the American Society for Testing and Materials (ASTM) describes test methods for the mechanical characterization of plates and screws for orthopedic internal fixation. The devices covered are fabricated from one or more hydrolytically degradable (absorbable) polymers, resins, or resin composites.

This standard establishes common terminology to describe the size and other physical properties of absorbable implants and performance definitions related to the performance of absorbable devices. This standard establishes standard test methods to consistently measure the performance-related mechanical properties of absorbable devices when tested under defined conditions such as pretreatment, temperature, humidity, and test machine speed.

However, this standard may not be suitable for all absorbable devices, particularly those that have limited hydrolytic susceptibility and are primarily degraded in vivo by enzymatic action. The user should consider the suitability of the standard for the particular absorbable device and its potential application.

For the purposes of this document, the following terms and definitions apply:

• Absorbable refers to an initially apparent foreign substance or matter that can pass through or be assimilated by cells or tissues in the body, either directly or through intended degradation.
• Resorbable composite refers to an absorbable polymer resin or structure containing particulate or fibrous bioactive or absorbable filler material.
• Bone anchor refers to a device or a component of a device that provides attachment to bone.
• Bone plate refers to a device designed to align two or more bone segments by primarily covering a fracture or defect when fixed with screws or cerclage wire. A bone plate has two or more holes. Its width and thickness are usually not the same size.
• Deterioration refers to the reduction or deterioration of the mechanical or other functional performance characteristics of a device.
• Hydrolytically degradable polymer refers to any polymeric material in which the primary mechanism of chemical breakdown in the body is hydrolysis (water reacting with the polymer, causing the chain to break).
• Suture anchor refers to a device that provides a means of attaching soft tissue to bone with sutures.
• Insertion depth (mm) refers to the linear progression of a device into the test block measured before testing relative to its seating position on the surface of the test block.

Absorbable devices are designed to break down and absorb over time after insertion, making removal surgery unnecessary, which is especially advantageous for pediatric patients.

As the polymer degrades due to hydrolytic reaction with the environment, the mechanical performance of the device also deteriorates. The key to developing mechanically effective fracture fixation systems based on absorbable devices is to provide adequate fixation strength and stiffness over a longer time period than expected for fracture healing. Once the fracture has healed, the device can be completely absorbed by the body. The biological performance of the device can be enhanced by incorporating bioactive fillers into the polymer, particularly for application to a bony site.

Absorbable devices are tested using test methods similar to those used to evaluate conventional metallic devices. For absorbable devices, pretest conditioning requirements, usage requirements, and time-dependent mechanical property evaluations are considered.

This standard and accompanying test methods are intended to complement the more general considerations regarding the evaluation of absorbable polymeric implants described in the standard “ASTM F2902-16e1 Standard guide for the evaluation of absorbable polymeric implants.”

Absorbable devices may be fabricated from one of the following materials: L-lactide, D-lactide, D,L-lactide, glycolide, or other known hydrolytically degradable polymer resins or copolymers. Other absorbable polymeric, ceramic, or metallic-based structures that degrade nonhydrolytically, such as those described in ASTM F1088-23, ASTM F1185-19, and ASTM 3160-21, may be considered, but precautions should be taken to provide a suitable degradation environment for the materials.

The manufacturer must ensure that the materials used in the manufacture of absorbable implants are suitable for implantation in the body. Methods for assessing the suitability of a material are described in the ISO 14630 standard.

Among the numerous testing, measurement, analysis and evaluation studies that our organization has carried out for businesses in various sectors, our organization also provides testing services defined in the standard “ASTM F2502-17 Standard specification and test methods for absorbable plates and screws for internal fixation implants” with its trained and expert staff and advanced technological equipment.