Triathlon PSR Outcomes Study

Inclusion Criteria: 1. Patient has signed an IRB/EC approved; study specific Informed Patient Consent Form. 2. Patient is a male or non-pregnant female, skeletally mature, age 18-75 years at time of study device implantation. 3. Patient has a diagnosis of Non-Inflammatory Degenerative Joint Disease (NIDJD). 4. Patient is a candidate for primary cemented total knee replacement. 5. Patient is willing and able to comply with postoperative scheduled clinical and radiographic evaluations and rehabilitation. Exclusion Criteria: 1. Patient has a Body Mass Index (BMI) \> 45. 2. Patient is already participating in the study for a contralateral total knee replacement. 3. Patient has a diagnosis of avascular necrosis or inflammatory arthritis. 4. Patient has an active or suspected latent infection in or about the affected knee joint at time of study device implantation. 5. Patient has any mental or neuromuscular disorder which would create an unacceptable risk of prosthesis instability, prosthesis fixation failure, or complications in postoperative care. 6. Patient has a compromised bone stock which cannot provide adequate support to the prosthesis. 7. Patient is immunologically suppressed or receiving steroids in excess of normal physiological requirements (e.g. \> 30 days). 8. Patient is diagnosed with lumbar radicular pain. 9. Patient has severe instability of the knee joint secondary to the absence of collateral ligament integrity and function. 10. Patient has a known sensitivity to device materials. 11. Patient is a prisoner.