The Orthopaedic Research Laboratory (ORL) performs research in the field of orthopaedics. The biomechanical section focusses on bone, soft tissues and on pre-clinical testing of implants. We are specialized in mechanical testing, computational analyses, histological analyses and animal testing. Our strength lies in combining these techniques, allowing for cross-validation and innovative research.
The ORL has one fully calibrated MTS testing machines with loading ranges up to 15 Kn and also has the capability to apply a torque up to 225 Nm. We have capabilities to design dedicated experimental set-ups to assess strength, stability and fatigue properties of various materials and reconstructions. Reconstructions are often tested in combination with cadaveric materials which we obtain from the Anatomical department of the Radboudumc. Testing conditions can vary from dry to simulated body fluids at 37 degrees centrigrade.
The ORL has a Bose ElectroForce BioDynamic test machine. This uni-axial loading machine can apply a maximal load of 200 N. Dynamic or static loading can be performed under incubator circumstances. Hence, tissue growth and biological specimens within a sterile environment can be tested, and the biological tissue can be subjected to in-vivo biomechanical loads.
We are experts in the applications of radiostereometric analysis (RSA) to quantify the 3-D motion of one segment to the other. This is of high relevance if we want to determine the migration of an implant relative to bone upon dynamic loading, or if we want to determine how much soft tissues deforms due to loading or kinematic changes. Depending on the experimental conditions the accuracy of this technique is around 50 microns.
The ORL utilizes Tekscan pressure mapping to assess how joint loading is altered due to interventions such as cartilage repair, ACL reconstruction, implant positioning and other reconstructive techniques. We have ample experience in calibrating and registering the pressure maps in a reliable way.
Digital image correlation and tracking is an optical method that employs tracking and image registration techniques for accurate displacement and strain measurements. We utilize this technique to quantify micro-motions between implant and bones and to determine strains in soft tissues.
To measure 3D motions of segments the ORL has the capability of using a Polhemus Fastrak motion tracking system. This system is based on electromagnetic principles which limits the experiments to non-metal investigations. This system can be easily used to quantify joint kinematics and how they change due to an interventions such as placing a prosthetic component or performing a surgical reconstruction. Errors are smaller than 1 mm in translation and 1 degree in rotations.