Inclusion Criteria:  Patient is of legal age and skeletally mature Patient is willing and able to provide written Informed Consent by signing and dating the IRB-approved Informed Consent document Patient is willing and able to complete scheduled follow-up evaluations as defined in the study protocol Patient qualifies for total knee arthroplasty based upon physical exam and medical history, and meets the approved indications for use of the Persona Ti-Nidium Knee System and Vivacit-E polyethylene articulating surface Independent of study participation, patient is a candidate for the commercially available Persona Ti-Nidium Knee and Vivacit-E polyethylene articulating surface, implanted in accordance with product labeling  Study Device Inclusion Criteria:  The Persona Ti-Nidium Total Knee is intended for patients with severe pain and disability due to the following:  Rheumatoid arthritis, osteoarthritis, traumatic arthritis, polyarthritis. Collagen disorders, and/or avascular necrosis of the femoral condyle. Post-traumatic loss of joint configuration, particularly when there is patellofemoral erosion, dysfunction or prior patellectomy. Moderate valgus, varus, or flexion deformities.  Exclusion Criteria:  Patient is unwilling to sign the Informed Consent Patient is currently participating in any other surgical intervention or pain management study Patient is pregnant or considered a member of a protected (vulnerable) population whose inclusion in the study is inappropriate (e.g. prisoner, mentally incompetent) Patient has a mental or neurologic condition who is unwilling or incapable of following postoperative care instructions Patient has a condition which would, in the judgement of the Investigator, place the patient at undue risk or interfere with the conduct of the study Patient is institutionalized or is a known drug abuser, a known alcoholic or cannot understand the requirements of study participation  Study Device Exclusion Criteria  Previous history of infection in the affected joint and/or other local/systematic infection that may affect the prosthetic joint Insufficient bone stock on femoral or tibial surfaces Skeletal immaturity Neuropathic arthropathy Osteoporosis or any loss of musculature or neuromuscular disease that compromises the affected limb A stable, painless arthrodesis in a satisfactory functional position Severe instability secondary to the absence of collateral ligament integrity Rheumatoid arthritis (RA) accompanied by an ulcer of the skin or a history of recurrent breakdown of the skin The kinematic alignment surgical technique is contraindicated for patients with greater than 5° valgus deformity with medial collateral ligament (MCL) insufficiency