5.1 This test method is intended to investigate the resistance of a glenoid component to loosening. Glenoid loosening is the most common clinical complication in total shoulder arthroplasty (see X1.1). The method assumes that loosening occurs because of edge loading, often called the rocking-horse phenomenon.

5.2 This test method can be used both to detect potential problems and to compare design features. Factors affecting loosening performance include articular geometry, flange geometry, materials, fixation design, bone quality, and surgical technique.

1.1 These test methods measure how much a prosthetic anatomic glenoid component rocks or pivots following dynamic displacement of the humeral head between opposing glenoid rims (e.g., superior-inferior or anterior-posterior). Motion of the anatomic glenoid component is quantified by measuring displacement opposite each loaded rim after dynamic rocking. Similarly, these test methods measure how much a prosthetic reverse glenoid baseplate rocks or pivots following dynamic articulation of the reverse glenoid component with a mating humeral liner. Motion of the reverse glenoid baseplate is quantified by measuring displacement before and after dynamic articulation.

1.2 These test methods cover shoulder replacement designs with monolithic or modular anatomic glenoid components for cemented fixation as well as reverse glenoid components for uncemented fixation with the use of screws.

1.3 This test method is intended to be used to compare or rank device designs.

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

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, health, and environmental practices and determine the applicability of regulatory limitations prior to use.

1.6 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.