Triathlon® Partial Knee Replacement (PKR) Outcomes Study

A Prospective, Post-market, Multi-center Study of the Outcomes of the Triathlon® Partial Knee Resurfacing (PKR) Unicondylar Knee System

The purpose of this study is to compare the 10-year Knee Society Score (KSS) functional results of the Triathlon PKR Unicondylar Knee to the 10-year Knee Society Score (KSS) functional results of the Triathlon Cruciate Retaining (CR) Total Knee.

Inclusion Criteria:

• The subject is a male or non-pregnant female 21-75 years of age at the time of enrollment.
• The subject requires a primary cemented unicompartmental knee replacement.
• The subject has a diagnosis of osteoarthritis (OA) or posttraumatic arthritis (TA).
• The subject has clinically intact cruciate and collateral ligaments and no ligamentous instability is present.
• The subject has less than 10 degrees of flexion contracture and greater than 90 degrees of flexion.
• The subject's preoperative mechanical alignment is less than 15 degrees of varus and 15 degrees of valgus.
• The subject has signed the Institutional Review Board (IRB) approved study specific Informed Patient Consent Form.
• The subject is willing and able to comply with postoperative scheduled clinical and radiographic evaluations and rehabilitation.

Exclusion Criteria:

• The subject has inflammatory arthritis or avascular necrosis(AVN).
• The subject is obese, BMI > 35.
• The subject has a history of total or unicompartmental (contralateral compartment and/or patellofemoral joint) reconstruction of the affected joint.
• The subject has a history of anterior cruciate ligament (ACL) reconstruction.
• The subject has had a high distal femoral, or proximal tibial osteotomy.
• The subject has a mental, neuromuscular or neurosensory disorder, which would create an unacceptable risk of prosthesis instability, prosthesis fixation failure, or complications in post-operative care and/or limit the ability to assess the performance of the device.
• The subject has a systemic or metabolic disorder leading to progressive bone deterioration that the surgeon feels would affect the overall outcome of the study.
• The subject is immunologically suppressed, or is receiving chronic steroids (>30 days duration).
• The subject has a known sensitivity to device materials.
• The subject's bone stock is compromised by disease and/or infection which cannot provide adequate support and/or fixation to the prosthesis.
• The subject's bone stock is compromised by a prior implantation which cannot provide adequate support and/or fixation to the prosthesis.
• The subject has an active or suspected latent infection in or about the knee joint.
• The subject is a prisoner.