Fixation of total knee replacement implants
This collaboration between the Orthopaedic Research Lab of Radboudumc (Nijmegen, The Netherlands) and DePuy Synthes (Leeds, UK) focuses on the primary fixation of total knee replacement implants.
Total knee replacement is a popular orthopaedic intervention for patients suffering from degenerated knees, with more than 30,000 operation each year in The Netherlands. The operation provides pain relief and restores patient mobility, but at the moment it does not provide a life-long solution, particularly for younger patients. To prevent future re-operations, this project investigates the fundamental principles of implant fixation.
The project adopts a hybrid approach of experimental testing and computational modeling to investigate the fixation biomechanics. Experimental tests will be performed on cadaver bone tissue to establish the mechanical response of the bone, and how this is affected by the bone quality. This project will particularly focus on the combination of creep, relaxation, and plastic deformation of the bone. Based on these tests, material models will be developed that serve as input to advanced computational models. The computational models will be used to simulate the mechanics of fixation of total knee replacement implants. The knee models will simulate the relative motions at the interface between the implant and the bone, also referred to as ‘micromotions’. The interface micromotions are a measure for how bone will grow into the implant surface, providing long-term stability and fixation.
The project will deliver mechanically validated models that can be used to investigate the effects of variations in patient characteristics, implant design, and surgical procedure on primary fixation. This enables population-wide analyses that allow us to develop the next generation of total knee replacement surgery, providing a lifetime solution for knee patients.