Shoulder Endoprosthesis - Wear and Fatigue Testing

Questmed GmbH offers testing for wear of shoulder endoprosthesis according ASTM F1378 and our internal wear testing standard AW-13.
We are also specialised in testing anatomical shoulder endoprosthesis and reverse shoulder endoprosthesis.
Furthermore we offer fatigue testing in compliance with ASTM F1829 and ASTM F2028.

Shoulder Implant Shoulder wear test setup

Our shoulder wear simulator is available with two banks of three test stations. Our AMTI simulator (ADL-K6-01) replicates the loading and full range of multi-axis motion associated with activities of daily living. The test system provides unparalleled test accuracy through its virtual soft tissue control, which couples force control with a software model that accounts for the constraining influence of the tissue structure surrounding the shoulder. The AMTI simulator meets the requirements for shoulder wear testing.

Parameters of the Wear Test

The tests will be conducted load controlled, so that the flexion and loads specified in the motion cycle will be applied to the test samples. The axial force specified in the motion cycle will be applied to the active load soak sample.

  • Axial Load 200 N – 600 N (motion cycle)
  • Abduction / Adduction -10 degree – +40 degree (motion cycle)
  • Translation 0 N- +256 N (motion cycle)
  • Elevation -1 Nm – +1 Nm (motion cycle)
  • Test Frequency 1 Hz
  • Test Temperature 37°C +/- 2
  • Test Medium Calf serum (Protein content 20 g/l)
  • Cycles 5 000 000

Wear Measurement

The wear of the polyethylene components will be determined by the net mass loss according to ISO 14243-2. The polyethylene components will be weighted before and after the wear test as well as during the wear test, overall seven times. The inspections will be performed after 500 000 cycles, 1 million cycles and every 1 million cycles.

Axial fatigue and durability testing

Axial tests runs with 5 Hz at 23 °C air or 37 °C tempered 0.9 % saline ringer's solution.
For fatigue testing 6 identical samples are required.

Shoulder fatigue test setup
Parameters of the fatigue test:
  • samples: 6
  • E [mm]: customized resection-line
  • tolerance of E [mm]: ± 2
  • inclination α [deg]: 30
  • rotation β [deg]: 45
  • tolerance of α and β [deg]: ± 1
  • load FR [N]: 2400
  • cycles ND [cycles]: 1.000.000
  • frequency f [Hz]: 5
  • medium/enviroment: Air 23 °C, Saline 37 °C

Shoulder fatigue test system

Questmed Shoulder Testing

Download a presentation of questmed shoulder testing
Download "Questmed Shoulder Testing" as PDF.