Scorpio NRG (eNeRGize) Cruciate Retaining (CR) Post-market International Outcome Study

The purpose of this study is to collect basic function, radiographic and patient satisfaction data for observation and analysis.

Evaluation of the effect of the component design on functional performance by comparing postoperative Knee Society Scores (KSS) with preoperative.

Evaluate post-operative radiographic findings. Evaluate the effect of component design on patient activity by comparing postoperative Lower Extremity Activity Scale (LEAS) with preoperative.

Evaluate patient satisfaction using Short-Form-36 Health Survey (SF-36). Evaluate quality of life using Knee Injury and Osteoarthritis Outcome Score (KOOS) and EuroQuol-5 dimension patient questionaire (EQ-5D).

Eligibility Criteria:
Inclusion Criteria:

1. Patient is able to understand the meaning of the study and is willing to sign the Ethic Commission approved, study specific Informed Patient Consent Form.
2. The subject is a male or non-pregnant female between 40 and 75 years of age.
3. The subject requires a primary total knee replacement.
4. Patients with osteoarthritis or posttraumatic arthritis (no rheumatoid arthritis)
5. The subject has intact collateral ligaments.
6. The subject is willing and able to comply with postoperative scheduled clinical and radiographic evaluations and rehabilitation.
7. The subject is capable of understanding the patient scores in the national language.

Exclusion Criteria:

1. The subject is morbidly obese, defined as Body Mass Index (BMI) of \> 40.
2. The subject has a history of total or unicompartmental reconstruction of the affected joint.
3. The subject will be operated bilaterally.
4. Patients who had a Total Hip Arthroplasty (THA) on contralateral and/or ipsilateral side within the last year that is considered to have an unsatisfactory outcome (Patients with contralateral and/or ipsilateral THA \> 1 year ago with good outcome can be included in the study).
5. Patients who had a Total Knee Arthroplasty (TKA) on contralateral side within the last 6 months that is considered to have an unsatisfactory outcome. (Patients with contralateral TKA \> 6 months ago with good outcome can be included in the study).
6. Patients who will need lower limb joint replacement for another joint within one year.
7. The subject has had a high tibial osteotomy or femoral osteotomy.
8. The subject has a neuromuscular or neurosensory deficiency, which would limit the ability to assess the performance of the device.
9. The subject has a systemic or metabolic disorder leading to progressive bone deterioration.
10. The subject is immunologically suppressed or receiving steroids in excess of normal physiological requirements.
11. The subject's bone stock in compromised by disease or infection which cannot provide adequate support and/or fixation to the prosthesis.
12. The subject has had a knee fusion to the affected joint.
13. The subject has an active or suspected latent infection in or about the knee joint.
14. Proven or suspected hypersensitivity to one or more than one of the device materials (see Appendix 10 table of chemical composition).
15. Female patients planning a pregnancy during the course of the study.
16. The subject is a prisoner.
17. severe deformities: varus/valgus deformity \>10° (mech. axis), bowed femur \> 20 degree, flexion contracture \>10°