X-3 Polyethylene Survival Outcomes Study

Mayo Clinic

Status: Completed

Conditions: Arthroplasty, Replacement, Knee; Total Knee Replacement

Treatments: Device: N2Vac Polyethylene; Device: X3 Polyethylene

Study type: Interventional

Funder types: Other; Industry

Identifiers

NCT00493792

06-003093 (Other Identifier)

Details and patient eligibility

About

The goal of this clinical trial is to compare two types of polyethylene (Stryker Orthopaedics N2Vac and their X3 polyethylene) prostheses that are used in total knee replacements. The primary outcome will analyze whether or not prostheses require a revision surgery 10 years post knee replacement. Other outcomes such as reoperation rate, complications, radiographic results, and clinical outcomes will be collected.

It is hypothesized that X3 would perform equally well to N2Vac at 10 years.

Full description

This is a prospective, randomized and blinded clinical trial. Participants will be assessed pre-operatively and post-operatively at three months and two, five, seven and ten years. The primary aim of the study is to compare the survivorship of two types of polyethylene (conventional N2Vac and highly cross-linked X3, both FDA approved via 510k clearance) used in a fixed-bearing total knee system in patients undergoing cemented total knee arthroplasty. Specifically, the primary endpoint will be the revision rate at ten years. 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), 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 patient.

Enrollment: 518 patients

Sex: All

Ages: 21 to 85 years old

Volunteers: No Healthy Volunteers

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.

Trial design

Primary purpose: Treatment

Allocation: Randomized

Interventional model: Parallel Assignment

Masking: Single Blind

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518 participants in 2 patient groups

Control

Active Comparator group

Description:

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.

Treatment:

Device: N2Vac Polyethylene

Treatment

Experimental group

Description:

Stryker Orthopaedics 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.

Treatment:

Device: X3 Polyethylene