Triathlon Total Stabilizer (TS) Outcomes Study

• To evaluate the effect of Joint Line restoration on postop stability, anterior knee pain & functional performance. [ Time Frame: 6 weeks ] [ Designated as safety issue: No ]
• To evaluate the change between preop & postop outcomes other than the KSS for the Triathlon® TS group, as well as the change for all outcomes before & after date of availability for the extended condylar design. [ Time Frame: 5 years ] [ Designated as safety issue: No ]
• To review radiographic stability, revision rates and complications for those implanted with the Triathlon® TS Total Knee System. [ Time Frame: 5 years ] [ Designated as safety issue: Yes ]

This study will be a prospective, non-randomized evaluation of the change between preoperative and postoperative outcomes for those receiving the Triathlon® TS Total Knee System for a revision knee operation. When available, the Triathlon® TS Extended Condyle Femur (ECF) may also be included. The mean total Knee Society Score (for pain, motion and function) change is not 10% worse than, or is superior to, the expected change according to published revision total knee replacement data, for cases implanted with the Triathlon® TS Total Knee System as compared from preoperative to 2 years postoperative.

Inclusion Criteria:

• Patient has signed an IRB approved, study specific Informed Patient Consent Form.
• Patient is a male or non-pregnant female age 18 years or older at time of study device implantation.
• Patient is a candidate for revision of all femoral and tibial components of a total knee replacement.
• Patient is willing and able to comply with postoperative scheduled clinical and radiographic evaluations and rehabilitation.

Exclusion Criteria:

• Patient has a Body Mass Index (BMI) > 40.
• Patient has an active or suspected latent infection in or about the affected knee joint at time of study device implantation.
• Patient has a neuromuscular or neurosensory deficiency, which limits the ability to evaluate the safety and efficacy of the device.
• Patient is diagnosed with a systemic disease (e.g. Lupus Erythematosus) or a metabolic disorder (e.g. Paget's Disease) leading to progressive bone deterioration.
• Patient is immunologically suppressed or receiving steroids in excess of normal physiological requirements (e.g. > 30 days).
• Patient has a failed unicondylar knee prosthesis.
• Patient has a known sensitivity to device materials.
• Patient is a prisoner.