Questmed GmbH - Tests for Bone Plates, Bone Screws and Bone Nails
Questmed offers static and fatigue testing of bone plates and bone screws.
Usually we are testing according to ASTM F382 (Bone Plate), ASTM F3437 (Small Bone Plates), ASTM F543 (Bone Screw) and the osteosynthesis system (bone plate and bone screws assembled as axial static bending test).
We also testing Intramedullary Fixation Devices (IMFD) according ASTM F1264, static and fatigue testing for torsion and four-point bending.
We are running 17 dynamic test systems with an force of up to 10 kN for bone plate testing.
Bone plates - Performance criteria
Performance criteria for bone plates published by the
FDA are shown in the table.
| Intended Anatomical Location of Bone Plate | Minimum Bending Strength (N-m) | Minimum Bending Structural Stiffness (N-m²) |
|---|---|---|
| Humerus | 11.6 | 4.39 |
| Elbow (Distal Humerus and Ulna) | 6.7 | 0.89 |
| Hand, Wrist and Forearm | 1.6 | 0.18 |
| Femur & Proximal Tibia | 26.3 | 8.66 |
| Distal Tibia | 11.9 | 3.49 |
| Fibula | 2.3 | 0.17 |
| Foot | 1.2 | 0.13 |
| Clavicle | 11.9 | 1.69 |
Bone screws - Performance criteria
Performance criteria for bone screws published by the
FDA are shown in the tables.
| Nominal Major Diameter (mm) | Torsional Yield Strength (Nm) |
|---|---|
| 1.5 | 0.16 |
| 2.0 | 0.35 |
| 2.5 | 0.6 |
| 2.7 | 1.0 |
| 3.0 | 1.0 |
| 3.5 | 2.1 |
| 4.0 | 2.3 |
| 4.5 | 3.5 |
| 5.0 | 4.3 |
| 5.5 | 5.9 |
| 6.0 | 9.5 |
Driving Torque
The maximum torque recorded in insertion and removal testing into a minimum of 20 pcf bone foam should be 50% of or less than the torsional yield strength of the bone screw.
Additionally, visual inspection should be performed on screws following their removal, and images of the final test samples should be provided to demonstrate that the screw threads adequately resist damage, such as disassociation of the screw thread from the screw body.
Axial Pullout Strength
| Nominal Major Diameter (mm) | Theoretical Pullout Strength (N) |
|---|---|
| 1.5 | 45.6 |
| 2.0 | 50.5 |
| 2.5 | 55.5 |
| 2.7 | 79.5 |
| 3.0 | 92.0 |
| 3.5 | 112.5 |
| 4.0 | 148.4 |
| 4.5 | 152.3 |
| 5.0 | 230.7 |
| 5.5 | 336.0 |
| 6.0 | 468.6 |
| 6.5 | 503.5 |