Inclusion Criteria:  Subject is a suitable candidate for a TKA procedure using CORI and a corresponding S+N Knee Implant System.  Subject requires a cemented TKA as a primary indication that meets any of the following condition:  Degenerative joint disease, including osteoarthritis Rheumatoid arthritis Avascular necrosis Requires correction of functional deformity Requires treatment of fractures that were unmanageable using other techniques Subject is of legal age to consent and considered skeletally mature (≥ 18 years of age at the time of surgery) Subject agrees to consent to and to follow the study visit schedule (as defined in the study protocol and informed consent form), by signing the Ethical Committee (EC) or Institutional Review Board (IRB) approved informed consent form. Subject plans to be available through two (2) year postoperative follow-up. Applicable routine radiographic assessment is possible.  Exclusion Criteria:  Subject requires a TKA on the index joint as a revision for a previously failed surgery, or has the need for complex implants, or any other implant than a standard TKA (e.g. stems, augments, or custom-made devices). Subject has been diagnosed with post-traumatic arthritis. Subject requires bilateral TKA. Subject does not understand the language used in the Informed Consent Form. Subject does not meet the indication or is contraindicated for TKA according to the specific Smith+Nephew Knee System's Instructions For Use (IFU). Subject has active infection or sepsis (treated or untreated). Subject is morbidly obese with a body mass index (BMI) greater than 40. Subject is pregnant or breast feeding at the time of surgery. Subject, in the opinion of the Investigator, has advanced osteoarthritis or joint disease at the time of surgery and was better suited for an alternate procedure. Subject has a condition(s) that may interfere with the TKA survival or outcome (i.e., Paget's or Charcot's disease, vascular insufficiency, muscular atrophy, uncontrolled diabetes, moderate to severe renal insufficiency or neuromuscular disease, or an active, local infection). Subject in the opinion of the Investigator has an emotional or neurological condition that would pre-empt their ability or willingness to participate in the study including mental illness, intellectual disability, drug or alcohol abuse. Subject, in the opinion of the Investigator, has a neuromuscular disorder that prohibited control of the index joint. Subject is a prisoner or meets the definition of a Vulnerable Subject per International Organization for Standardization (ISO) 14155:2011 Section 3.44.