NitrX Total Knee Arthroplasty RSA

Component Migration, Polyethylene Wear, and Joint Inflammation of the Evolution Versus Evolution NitrX Total Knee Arthroplasty System

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.

Inclusion Criteria:

• Symptomatic osteoarthritis of the knee indicating primary total knee arthroplasty
• Varus knee deformity of 0 to 10 degrees
• Sufficient ligamentous function to warrant retention of the posterior cruciate ligament
• Between ages of 21 and 80 inclusive
• Patients willing and able to comply with follow-up requirements and self-evaluations
• Ability to give informed consent
• No contraindications to Magnetic Resonance Imaging (MRI)

Exclusion Criteria:

• Active or previous infection
• Medical condition precluding major surgery
• Inflammatory arthropathy
• Prior Patellectomy
• PCL deficiency
• Major Coronal plane deformity
• Valgus deformity
• Bone defects requiring augments, cones and/or stemmed implants