An interventional study of Total Knee Arthroplasty with Evolution® NitrX™ Knee System and Total Knee Arthroplasty with Evolution Knee System in Total Knee Arthroplasty, Knee Osteoarthritis and Radiostereometric Analysis, sponsored by London Health Sciences Centre Research Institute OR Lawson Research Institute of St. Joseph's. Active, not recruiting at 1 site in Canada. Open to participants aged 21 Years to 80 Years. Per ClinicalTrials.gov, last updated 2026-09-22.
Sponsored by London Health Sciences Centre Research Institute OR Lawson Research Institute of St. Joseph's · Not applicable, Interventional, and Treatment
Metal hypersensitivity is a recognized complication in some patients following total joint arthroplasty. This can result in a reaction to metal particles from the implants placed in the joint and cause tissue injury. The Evolution® NitrX™ (MicroPort Orthopaedics, Memphis, TN) knee implant was designed with the addition of a coating meant to create a barrier against the release of metal ions. The primary purpose of this study is to compare the Evolution and Evolution NitrX implant (implants your surgeon uses in total knee arthroplasty surgery). This study will compare the stability of these knee implants (any movement the implant makes after surgery) through the use of specialized xrays, called "radiostereometric analysis" (RSA for short). The investigators will also compare levels of circulating metal particles with blood draws and the effects of any circulating metal with MR imaging. The investigators will also be looking at the participants clinical outcomes using joint function and patient satisfaction questionnaires. A total of 50 patients will be enrolled into the study.
3,302 studies on the registry are indexed under Osteoarthritis, Knee; 608 are open to participants now.
This study's planned enrollment of 50 is below the median of 70 across 2,731 interventional studies indexed under Osteoarthritis, Knee.
Browse Osteoarthritis, Knee studies →London Health Sciences Centre Research Institute OR Lawson Research Institute of St. Joseph's is the lead sponsor of 309 studies on the registry; 126 are open to participants now.
Counted across the registry records on this site, refreshed daily.
Exclusion Criteria:
Patients will undergo total knee arthroplasty with the Evolution Total Knee System
Device: Total Knee Arthroplasty with Evolution Knee System
Patients will undergo total knee arthroplasty with the NitrX Evolution Total Knee System which has the specialized protective coating
Device: Total Knee Arthroplasty with Evolution® NitrX™ Knee System
Patients will receive cemented Evolution knee system with NitrX coating for their total knee arthroplasty.
Patients will receive cemented Evolution knee system without NitrX coating for their total knee arthroplasty.
Implant Migration (Tibial Component)
Model based Radiostereometric Analysis (RSA, specialized Xrays) will be used to register the location of the tibial implant components during supine and standing exams and measure implant movement. Changes throughout the different time points of potential tibial migration, with the use of the tibial bone beads, will be measured in millimeters.
Time frame: 2 years
Implant Migration (Femoral Component)
Model based Radiostereometric Analysis (specialized Xrays) will be used to register the location of the femoral components during supine and standing exams and measure implant movement. Changes throughout the different time points of potential femoral migration, with the use of the femoral bone beads, will be measured in millimeters.
Time frame: 2 years
Wear Rates
Model based Radiostereometric Analysis (specialized Xrays) will be used to register the location of the femoral and tibial components in both standing and supine exams where the minimum joint space width between components on the medial and lateral condyles can be calculated as a measurement (in millimeters) of polyethylene wear.
Time frame: 2 weeks (baseline), 6 weeks, 3 months, 6 months, 1 year, and 2 years.
Circulating metal levels
Patients will have blood drawn and the levels of circulating cobalt, chromium, and nickel will be measured in whole blood. One vial of blood will be drawn from the patient (in milliliters).
Time frame: Pre-operative, 1 and 2 years post-operatively.
Synovial Joint Inflammation observation
Patients will complete an MRI exam using metal artefact reduction sequences. Scans will be evaluated and scored for synovial inflammation and fibrosis, indicative of reactions to metal debris, and the presence of fibrous tissue at the bone-cement-implant interface, indicative of component loosening.
Time frame: 2 Years
Knee Injury and Osteoarthritis Outcome score (KOOS)
Patient reported outcome measure. Holds 42 items that asks patient about pain, functional daily living, and sport and recreation. Questionnaire measures levels in frequency (never to always) and severity (none to extreme). Scores are from 0-100, with higher scores indicating no knee problems.
Time frame: Pre-operative, 3 months, 1 year, and 2 year post-operative
Forgotten Joint Score (FJS)
Patient reported outcome measure observing the ability of a patient to forget about a joint due to successful treatment. Contains 12 items with frequency level measurement (never to mostly). The higher the score (0-100), the less aware the patient is of their affected joint when performing daily activity.
Time frame: Pre-operative, 3 months, 1 year, and 2 year post-operative
Veterans-Rand 12 Item Health Survey (VR-12)
Patient reported outcome measure observing physical and mental health status of patient. Contains 14 items measuring levels of severity (excellent to poor) and frequency (None of the time to Yes, all of the time). Higher scores indicate higher quality of life and vice versa.
Time frame: Pre-operative, 3 months, 1 year, and 2 year post-operative
European Quality of Life - 5 Dimension (EQ-5D)
Patient reported outcome measure. Standardized 5 item instrument measuring generic health status of patient. The EQ5D uses a Likert scale which assesses five states (mobility, self care, usual care, pain and discomfort and anxiety and depression) at five different levels - none(0), slight(1), moderate(2), severe(3) or unable to perform(5). Levels are coded 1-5 and an index score is then generated. Higher scores indicate higher health status of patient.
Time frame: Pre-operative, 3 months, 1 year, and 2 year
Metal Exposure/Sensitivity
Patient reported outcome measure. Screening tool for noting pre-operative environmental metal exposures. Questionnaire contains Yes or No questions. Higher scores would indicate greater exposure and/or metal sensitivity.
Time frame: Pre-operative
Plan to share: No
This study is active, not recruiting, as verified in Sep 2026. You cannot join it, but the record below documents what was studied.
Get an email when the registry record changes — status, dates, results — or when someone posts here.
Sign in to followQuestions and observations about this study, from anyone following it. Not medical advice, and not a channel to the study team — their contact details are on the registry record.
Sign in to join the discussion. Reading takes no account; posting does. You choose a display name, and a pseudonym is the default.
Nothing here yet. If you are running this trial, taking part in it, or weighing whether to, this is the place to say so.
London Health Sciences Centre Research Institute OR Lawson Research Institute of St. Joseph's