Significance and Use
Biodegradable devices are expected by intention to deteriorate over time once they are implanted into the body. This makes the removal operation obsolete, which is advantageous especially for pediatrics.
While the polymer degrades due to hydrolytic reaction with the environment, the mechanical performance of the device also deteriorates. The key to developing effective fracture fixation systems based on biodegradable devices is to provide an adequate level of fixation strength for a time frame that exceeds that expected for fracture healing. Once the fracture is healed, the device can be completely resorbed by the body.
Generally, biodegradable devices will be tested with similar test methods that are used to evaluate conventional metallic devices. In addition, one has to take into consideration the pre-test conditioning requirements, handling requirements, and time-dependent mechanical property evaluations for biodegradable devices.
FIG. 1 Screw Parameters
Scope
1.1 This specification and test methods covers a mechanical characterization reference for hydrolytically degradable polymer resin (from this point on referenced as "bioabsorbable") plates and screws for orthopedic internal fixation.
1.2 This specification establishes common terminology to describe the size and other physical characteristics of bioabsorbable implants and performance definitions related to the performance of bioabsorbable devices.
1.3 This specification establishes standard test methods to consistently measure performance-related mechanical characteristics of bioabsorbable devices when tested under defined conditions of pretreatment, temperature, humidity, and testing machine speed.
1.4 This specification may not be appropriate for all bioabsorbable devices. The user is cautioned to consider the appropriateness of the standard in view of the particular bioabsorbable device and its potential application.
1.5 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.
