Natalie Burkhard

Total knee arthroplasty (TKA) is an effective and clinically successful solution for advanced knee osteoarthritis. However, treatment for failed implants is a burden on both patients and the healthcare system, and this problem is likely to intensify because the number of patients requiring TKA and revision TKA is projected to grow by 673% and 601%, respectively, by the year 2030.

Infection is the most common cause of revision TKAs. Early diagnosis of infection is crucial to avoid revision surgery, but the multitude of complex clinical tests and the tendency of infections to mimic other conditions render early detection difficult. In fact, there currently exists no universal standard to diagnose infection in the early postoperative period. Many indicators for infection are recognized as both sensitive and specific via retrospective studies, but no system exists to continuously test for these indicators in a knee implant. 

Sponsored by Orthosensor, our team developed a continuous, implantable sensing modality for patients undergoing TKA to detect infection before necessitating revision surgery. We provided Orthosensor with an infection sensor implementation plan that involves: (1) identification of infection indicators and their respective sensing mechanisms by inspecting color and turbidity of synovial fluid, (2) design and fabrication of clinically relevant models for synovial fluid and the knee joint, (3) production of sensor output data for a range of healthy and infected synovial fluid conditions, and (4) establishment of threshold values for sensors that are sensitive and specific to infection.