X-3 Polyethylene Survival Outcomes Study

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.

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.