Knee Implant Testing

Element's expertise covers complete TKR systems and individual components. We test femurs, patellas, tibial trays, and tibial bearings for both bicondylar and unicondylar knee systems. Our specialized capabilities extend to UHMWPE components and high-flexion designs, with proven experience in evaluating total knee prostheses from individual parts to complete assemblies. We also provide testing for highly-constrained implants, offering a comprehensive assessment of these specialized designs.

Knee Implant Fatigue Testing 

• Tibial Tray (ASTM F1800 & ISO 14879) 

• Tibial Bearing Components 

• Femoral Implants 

• Tibial Insert Endurance under High Flexion 

Contact Pressure & Constraint Testing 

• Contact Pressure 

• Constraint Testing (ASTM F1223) 

Knee Implant Wear Testing 

• ISO 14243-1 or ISO 14243-3 

These tests include: 

• Fatigue Testing 

• Wear Testing 

• Range of Motion Testing 

• Contact Pressure using TEKscan capabilities 

• Bearing Interlocking Strength 

• Constraint 

• Particle Evaluation 

• Particle Evaluation including wear debris generation assessment and SEM/EDS analysis 

Benefit from complete testing support including protocol development, design assistance, and comprehensive project management. Our solutions encompass both force-controlled and displacement-controlled testing options, utilizing dedicated frames for efficient turnaround times. We offer specialized setups for feasibility studies and support throughout your regulatory submission process. Our material aging protocols ensure accurate simulation of real-world conditions to provide more realistic performance data.

Knee Implant Fatigue Testing 
Element’s fatigue testing validates knee implant designs for both feasibility and submission purposes. This includes: 

• Tibial Tray (ASTM F1800 & ISO 14879): Fatigue testing is done by fixing one half of the tibial baseplate and applying a load to the unsupported half. This test runs for 10 million cycles with five samples surviving under at least 900 N of load. 

• Tibial Bearing Components: For posterior-stabilized implants, shear fatigue testing on the UHMWPE tibial post is done to develop an S/N curve, with at least one sample running out to 10 million cycles. 

• Femoral Implants: Fatigue properties are evaluated under various flexion angles and cementing configurations. Both S/N curves and minimum run-out testing are conducted. 

• Tibial Insert Endurance under High Flexion: Tests UHMWPE inserts’ resistance to deformation and fracture under repeated deep knee bends. The test runs for 220,000 cycles at 2,275 N load, with pre- and post-test scans and constraint tests. 

Contact Pressure & Constraint Testing 
These tests measure the contact mechanics and resistance of knee implants to dislocation and motion. 

• Contact Pressure: Pressure-sensitive films are used to analyze tibiofemoral and femoral-patellar contact stress at various flexion angles and loads. 

• Constraint Testing (ASTM F1223): Both translational and rotational forces are applied to induce subluxation or a specific angle of rotation. This is crucial when comparing different types of knee inserts. 

Knee Implant Wear Testing 
Wear testing measures the wear rates between the femoral component and tibial insert and patella button under simulated knee movements. This testing examines the generation of wear debris and includes SEM/EDS analysis of wear particles to support your safety assessments. 

• ISO 14243-1 or ISO 14243-3: Simulates complex knee motions with axial, anterior/posterior, flexion/extension, and tibial rotation forces. The test runs for up to 5 million cycles, and post-testing mass loss is measured, followed by particle analysis using SEM/EDS. We offer both kinematic-based (displacement-controlled) and force-based (force-controlled) test methodologies to match your specific testing requirements. 

Advance your testing with our specialized equipment including dedicated knee implant testing frames, six test stations with two load/soak controls, environmental chambers for bovine solution testing, TEKscan pressure measurement systems, and SEM/EDS equipment for comprehensive particle analysis. Our facilities feature purpose-built testing environments optimized for knee implant evaluation.

Our Cincinnati laboratory is Element's global Center of Technical Excellence for medical device testing, supported by our team operating from Life Sciences hubs worldwide. Find your nearest hub on our Locations Page. 

Validate your advanced knee designs with specialized high-flexion endurance testing. Our comprehensive evaluation assesses UHMWPE insert performance under deep knee bend conditions with 220,000 cycles at 2,275 N load, supported by detailed pre- and post-test scans and constraint testing analysis.