X-3 Polyethylene Survival Outcomes Study

• The primary efficacy parameter is the revision rate for total knee arthroplasty.
• The key time point is ten years post-surgery.

• Active flexion, Passive flexion, Active extension, and Passive extension ROM at the 2, 5, 7 and 10-year visits. [ Time Frame: 10 ] [ Designated as safety issue: No ]
• KSS pain and motion scores at the 3 months, 2, 5, 7 and 10-year visit. [ Time Frame: 10 ] [ Designated as safety issue: Yes ]
• SF-12 v1 scores at the 3 months, 2, 5, 7 and 10-year visit. [ Time Frame: 10 ] [ Designated as safety issue: No ]
• Radiographic success/failure at the 3 months, 2, 5, 7 and 10-year visits. [ Time Frame: 10 ] [ Designated as safety issue: Yes ]
• Radiographic failure is defined as a score of 10 or greater according to the Knee Society Rotenographic Scoring System, regardless of symptoms. [ Time Frame: 10 ] [ Designated as safety issue: Yes ]

• Active flexion, Passive flexion, Active extension, and Passive extension ROM at the 2, 5, 7 and 10-year visits.
• KSS pain and motion scores at the 3 months, 2, 5, 7 and 10-year visit.
• SF-12 scores at the 3 months, 2, 5, 7 and 10-year visit.
• Radiographic success/failure at the 3 months, 2, 5, 7 and 10-year visits.
• Radiographic failure is defined as a score of 10 or greater according to the Knee Society Rotenographic Scoring System, regardless of symptoms.

A prospective, randomized, blinded clinical trial is proposed to compare Stryker Orthopaedics N2Vac Polyethylene to their X3 Polyethylene when used with the Triathlon Posterior Stabilized (PS) total knee system.

This is a fixed-bearing knee intended for use in patients undergoing cemented total knee arthroplasty. The devices to be used are both FDA approved via 510k clearance.

A total of 572 cases (286 per group) will be entered. Each patient will be assessed pre-operatively and post-operatively at three months and two, five, seven and ten years. The primary endpoint will be the revision rate at ten years. The result for these will be analyzed using an unconditional test of equivalence between two independent binomials. Chi-square analysis will be used to compare the instance of mortality, revision surgery, deep vein thrombosis, pulmonary embolus, neurovascular complication, and infection. Other outcome measures incorporated in the Knee Society Clinical rating scale will undergo appropriate generalized linear regression for the type of outcome involved. The primary aim of the study is to compare the survivorship of two types of polyethylene (conventional N2Vac and highly cross-linked X3) used in a fixed-bearing total knee system in patients undergoing cemented total knee arthroplasty. These results will be measured through radiographs at each post-operative interval with an independent radiograph review being performed after all patients have reached 7 and 10 year follow-up. Secondary results will also be collected and will focus on disease-specific (Knee Society Scores), global (SF-12 v1), and outcome measures. Radiographic results consisting of standing anteroposterior, lateral and Merchant views of the surgical knee will be recorded and analyzed. Completion of the initial investigation will occur at the 10-year interval after the last enrolled.

• Arthroplasty, Replacement, Knee
• Total Knee Replacement

• 1
  Stryker Orthopaedics N2Vac Polyethylene when used with a Triathlon Posterior Stabilized total knee system. This is a fixed- bearing knee intended for use in patients undergoing cemented total knee arthroplasty.
  Intervention: Device: Stryker X3 crosslink
• 2
  X3 Polyethylene when used with a Triathlon Posterior Stabilized total knee system. This is a fixed- bearing knee intended for use in patients undergoing cemented total knee arthroplasty.
  Intervention: Device: Stryker X3 crosslink

INCLUSION CRITERIA:

1. Subjects willing to sign the informed consent.
2. Subjects able to comply with follow-up requirements including post-operative weight bearing restrictions and self-evaluations.
3. Male and non-pregnant female subjects ages 21-85 years of age at the time of surgery.
4. Subjects requiring a primary total knee replacement.
5. Subjects with a diagnosis of osteoarthritis (OA), traumatic arthritis (TA), or avascular necrosis (AVN).
6. Subjects with intact collateral ligaments as determined by the surgeon investigator.

EXCLUSION CRITERIA:

1. Subjects with inflammatory arthritis.
2. Subjects with a history of total or unicompartmental reconstruction of the affected joint.
3. Subjects that have had a high tibial osteotomy or femoral osteotomy.
4. Subjects with neuromuscular or neurosensory deficiency, which would limit the ability to assess the performance of the device.
5. Subjects with a systemic or metabolic disorder leading to progressive bone deterioration.
6. Subjects that are immunologically compromised, or receiving chronic steroids (>30 days).
7. Subjects bone stock is compromised by disease or infection that cannot provide adequate support and/or fixation to the prosthesis.
8. Subjects with knee fusion to the affected joint.
9. Subjects with an active or suspected latent infection in or about the knee joint.
10. Subjects that are prisoners.