Physica CR and Physica PS Clinical Trial

Inclusion Criteria: 1. Male and females 2. Age 22-78 years 3. Any race 4. Ambulatory patients 5. Patients who have a medical condition with over 5 years of life expectancy 6. Patients with painful primary or secondary knee osteoarthritis 7. Patients who have undamaged and functional collateral and posterior cruciate ligaments for the group requiring Physica CR or Patients who have undamaged and functional collateral ligaments for the group requiring Physica PS 8. Patients with flexion ≥90° on the affected side 9. Patients with a fixed flexion contracture \<20° 10. Patients who understand the conditions of the study and are willing and able to comply with the prescribed rehabilitation and to perform all scheduled follow-up visits 11. Patients who have signed the Ethics Committee approved study-specific Informed Consent Form prior to the surgery Exclusion Criteria: 1. Previous partial knee replacement or patellofemoral joint replacement and previous patellectomy 2. Primary Total Knee Replacement (TKR) in the affected knee 3. Varus deformity \>20° or Valgus deformity \>15° 4. Patients with a fixed flexion contracture \>20° 5. Previous intra-articular fractures of the affected knee 6. Patients with previous methaphysal tibial or femoral osteotomy performed less than 5 years before the screening visit, in case of plate removal surgery it is done early than 1 year ago to screening. 7. Previous knee replacement on the contralateral side within the last year and whose outcome is achieving an KSS\< 60 points 8. Patients with symptomatic Osteoarthritis (OA) of the spine if the assessment of pain with Numeric Rating Scale is \>4 9. Patients with an history of infections (on the affected knee or systemic) 10. Muscular insufficiency or absence of muscoligamentous supporting structures required for adequate soft tissue balance 11. Patients who have damaged or absence of the posterior cruciate ligament for the group requiring Physica CR 12. Patients with known or suspicious metal hypersensitivity 13. Recurrent medical history of severe allergic or immune-mediated reactions 14. Vascular insufficiency of lower limbs severe enough to interfere with the study evaluation 15. Current treatment or treatment within the previous 2 years before the screening visit for malignant and life-threatening non-malignant disorders 16. Any clinically significant pathology based on clinical history that the Investigator feels may affect the study evaluation including: 1. any intercurrent chronic disease or condition that may interfere with the completion of the 5-year follow-up, such as liver disease, severe coronary disease, drug or alcohol abuse 2. significant neurological or musculoskeletal disorders or disease that may adversely affect gait and compromise functional recovery 3. neuromuscular or neurosensory deficit which would limit the ability to assess the performance of the device 4. known metabolic disorders leading to progressive bone deterioration 17. Patients who have known co-existent medical condition with less 5 years of life expectancy 18. Previous organ transplant surgery 19. Any psychiatric illness that would prevent comprehension of the details and nature of the study 20. Participation in any experimental drug/device study within the 6 months prior to the screening visit 21. Female patients who are pregnant, nursing, or planning a pregnancy