Comparing X-3 To N2vac Polyethylene With the Triathlon Total Knee System

The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Read our disclaimer for details. Identifier: NCT00665964
Recruitment Status : Withdrawn (Not funded at this time.)
First Posted : April 24, 2008
Last Update Posted : August 11, 2009
Stryker Canada LP
Information provided by:
Dalhousie University

Brief Summary:

Methodology: This study will be a randomized, multi-center evaluation comparing N2vac polyethylene inserts and patellas with X3 inserts and patellas when used in the Triathlon PS total knee system.

Study Duration: 12-18 month enrollment period + 10 year follow-up for each case years total duration

Multi-centre study


Primary: To compare the 10 year implant survival of the Triathlon PS total knee system when X3 polyethylene components are used to the same knee system when N2Vac components are used.

Secondary: To compare pain, function, radiographic outcomes, and health related quality of life of subjects in both treatment groups. Safety will be assessed by comparison of adverse events between the groups.

Number of Subjects 384 cases (197 each group)

Condition or disease Intervention/treatment Phase
Osteoarthritis Device: X-3 polyethylene Device: N2Vac polethylene Phase 4

Study Type : Interventional  (Clinical Trial)
Estimated Enrollment : 384 participants
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Double (Participant, Investigator)
Primary Purpose: Treatment
Official Title: A Prospective, Randomized, Multi-center Study Comparing the Ten-Year Survival for X-3 Polyethylene to N2vac Polyethylene When Used With the Triathlon Posterior Stabilized (PS) Total Knee System
Study Start Date : May 2008
Estimated Primary Completion Date : May 2020
Estimated Study Completion Date : May 2020

Resource links provided by the National Library of Medicine

U.S. FDA Resources

Arm Intervention/treatment
Experimental: X-3
X-3 polyethylene which is a new highly cross-linked poly that is theorized to be more durable in vivo
Device: X-3 polyethylene
highly cross-linked polyethylene for knee arthroplasty
Active Comparator: N2Vac polethylene
conventional polyethylene
Device: N2Vac polethylene
conventional polyethylene

Primary Outcome Measures :
  1. survival rate of polyethylene [ Time Frame: 10 years ]

Secondary Outcome Measures :
  1. pain [ Time Frame: 10 years ]
  2. function [ Time Frame: 10 years ]
  3. radiographic outcomes [ Time Frame: 10 years ]
  4. health related quality of life [ Time Frame: 10 years ]
  5. adverse events [ Time Frame: 10 years ]

Information from the National Library of Medicine

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Ages Eligible for Study:   21 Years to 75 Years   (Adult, Senior)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   No

Inclusion Criteria:

  • The subject requires a primary cemented total knee replacement.
  • The subject has a diagnosis of osteoarthritis (OA), traumatic arthritis (TA), or avascular necrosis (AVN).
  • The subject has intact collateral ligaments.
  • The subject has signed the ethic committee approved, study specific Informed Patient Consent Form.
  • The subject is willing and able to comply with post-operative scheduled clinical and radiographic evaluations and rehabilitation.

Exclusion Criteria:

  • The subject has inflammatory arthritis.
  • The subject is morbidly obese, BMI > 40.
  • The subject has a history of total or unicompartmental reconstruction of the affected joint.
  • The subject has had a high tibial osteotomy or femoral osteotomy.
  • The subject has a neuromuscular or neurosensory deficiency, that would limit the ability to assess the performance of the device.
  • The subject has a systemic or metabolic disorder leading to progressive bone deterioration.
  • The subject is immunologically suppressed, or receiving chronic steroids (>30 days duration).
  • The subject's bone stock is compromised by disease or infection and cannot provide adequate support and/or fixation to the prosthesis.
  • The subject has had a knee fusion at the affected joint.
  • The subject has an active or suspected latent infection in or about the knee joint.
  • The subject is a prisoner.

Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its identifier (NCT number): NCT00665964

Canada, Nova Scotia
QEII Health Sciences Centre
Halifax, Nova Scotia, Canada, B3H 3A7
Sponsors and Collaborators
Dalhousie University
Stryker Canada LP
Principal Investigator: Michael J. Dunbar Dalhousie University

Responsible Party: Michael J. Dunbar, Division of Orthopaedics, Dalhousie University Identifier: NCT00665964     History of Changes
Other Study ID Numbers: CDHA-RS/2007-249
First Posted: April 24, 2008    Key Record Dates
Last Update Posted: August 11, 2009
Last Verified: August 2009

Keywords provided by Dalhousie University:
total knee arthroplasty
posterior stabilized

Additional relevant MeSH terms:
Joint Diseases
Musculoskeletal Diseases
Rheumatic Diseases