This test method helps to assess the axial locking force of a modular taper. Examples of these devices are described in Specification . Some types of devices that may utilize this type of connection are the modular shoulder and modular hip prostheses. Additional means of evaluating the locking mechanisms of tapers may be appropriate, depending upon the design of the device.

This test method may not be appropriate for all implant applications. The user is cautioned to consider the appropriateness of the practice in view of the materials and design being tested and their potential application.

While this test method may be used to measure the force required to disengage tapers, any comparison of such data for various component designs must take into consideration the size of the implant and the type of locking mechanism evaluated.

1. Scope

1.1 This test method establishes a standard methodology for determining the force required, under laboratory conditions, to disassemble tapers of implants that are otherwise not intended to release. Some examples are the femoral components of a total or partial hip replacement or shoulder in which the head and base component are secured together by a self-locking taper.

1.2 This test method has been developed primarily for evaluation of metal and ceramic head designs on metal tapers but may have application to other materials and designs.

1.3 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.

1.4 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.

2. Referenced Documents (purchase separately) The documents listed below are referenced within the subject standard but are not provided as part of the standard.

ASTM Standards

E4 Practices for Force Verification of Testing Machines

F1636 Specification for Bores and Cones for Modular Femoral Heads

Keywords

arthroplasty; disassembly; heads; hip prosthesis; modular; shoulder prosthesis; tapers; Axial disassembly force; Ceramic head designs; Disassembly; Force; Locking mechanisms (of tapers); Metal head designs; Modular prostheses; Testing methods--surgical implants; Prostheses; Surgical implants;

ICS Code

ICS Number Code 11.040.40 (Implants for surgery, prothetics and orthotics)

Citing ASTM Standards

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