ASTM F1820 Insert push-out test*
The ASTM F1820 covers a standard methodology to determine the attachment strength between the modular acetabular shell and insert, to evaluate the effect of various locking mechanisms and includes three different test setups. The shell is fixed with a suitable clamping in all tests, so that a movement of the shell is prevented and at the same time a release of the insert is enabled. Before each test, the insert is fixed in the shell with a force of 2 kN (ASTM F2345).
- Axial Dissambley
Through a hole in the pole of the shell, a displacement is applied to the insert along the polar axis, until it is released from the shell and the resulting force is measured (axial locking strength).
- Offset Pullout or Lever Out Disassembly
For this test, a slit or bore ust be generated on the inner side of the inserts (approximately 80% of the depth of the inserts). An axial displacement parallel to the polar axis (offset pull-out test) is then applied to the insert via a beam. Alternatively, the insert can also be levered out (lever-out test) via a lever arm which engages in the slot or bore.
- Torque Out Disassembly
For this test, grooves have to be inserted parallel to the polar axis into the insert, into which a prepared head is attached. Alternatively, a ball head can also be bonded to the insert. A torsion is then applied over the head around the polar axis until the insert is released.
*We offer this testing service as part of our accredited scope.