Comparison of Alignment Achieved Using the VELYS Robotic-Assisted Solution Versus Manual Instrumentation in Total Knee Arthroplasty

Inclusion Criteria: 1. Subject is male or female and between the ages of 22 and 85 years at the time of consent, inclusive. 2. Subject has a severely painful and/or severely disabled joint resulting from osteoarthritis, post-traumatic arthritis or rheumatoid arthritis and in the opinion of the Investigator, is a suitable candidate for primary TKA using the devices described in this CIP with either resurfaced or non-resurfaced patellae. 3. Subject that is willing to give voluntary, written informed consent to participate in this clinical investigation and authorize the transfer of his/her information to the Sponsor 4. Subject is currently not permanently bedridden, as determined by the Investigator 5. Subject, in the opinion of the Investigator, is able to understand this clinical investigation and is willing and able to perform all study procedures and follow-up visits and co-operate with investigational procedures. 6. Subject is able to read and comprehend the Informed Consent Document as well as complete the required PROs in English. 7. Subject's pre-operative alignment is such that (in the opinion of the Investigator) it is appropriate for it to be adjusted to mechanical long leg alignment during surgery. Exclusion Criteria: 1. The Subject is a woman who is pregnant or lactating. 2. Contralateral knee has already been enrolled in this study. 3. Subject had a contralateral amputation. 4. Previous partial knee replacement (unicompartmental, bicompartamental or patellofemoral joint replacement), patellectomy, high tibial osteotomy or primary TKA in affected knee. 5. Subject has an active local or systemic infection 6. Subject has loss of bone or musculature, osteoporosis, neuromuscular compromise or vascular deficiency in the affected limb in sufficient degree to render the procedure unjustifiable in the opinion of the Investigator (e.g. absence of musculo-ligamentous supporting structures, joint neuropathy) 7. Subject has severe instability secondary to advanced loss of osteochondral structure or the absence of collateral ligament integrity. 8. Subject has participated in a clinical investigation with an investigational product (drug or device) in the last three (3) months. 9. Subject is currently involved in any personal injury litigation, medical-legal or worker's compensation claims.