This site became the new on June 19th. Learn more.
Show more Menu IMPORTANT: Listing of a study on this site does not reflect endorsement by the National Institutes of Health. Talk with a trusted healthcare professional before volunteering for a study. Read more... Menu IMPORTANT: Talk with a trusted healthcare professional before volunteering for a study. Read more... Menu
Give us feedback

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

This study has been withdrawn prior to enrollment.
(Not funded at this time.)
Stryker Canada LP
Information provided by:
Dalhousie University Identifier:
First received: April 22, 2008
Last updated: August 10, 2009
Last verified: August 2009

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 Intervention Phase
Osteoarthritis Device: X-3 polyethylene Device: N2Vac polethylene Phase 4

Study Type: Interventional
Study Design: Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Double Blind (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

Resource links provided by NLM:

Further study details as provided by Dalhousie University:

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

Secondary Outcome Measures:
  • pain [ Time Frame: 10 years ]
  • function [ Time Frame: 10 years ]
  • radiographic outcomes [ Time Frame: 10 years ]
  • health related quality of life [ Time Frame: 10 years ]
  • adverse events [ Time Frame: 10 years ]

Estimated Enrollment: 384
Study Start Date: May 2008
Estimated Study Completion Date: May 2020
Estimated Primary Completion Date: May 2020 (Final data collection date for primary outcome measure)
Arms Assigned Interventions
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


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.
  Contacts and Locations
Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the Contacts provided below. For general information, see Learn About Clinical Studies.

Please refer to this study by its identifier: 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
  More Information

Responsible Party: Michael J. Dunbar, Division of Orthopaedics, Dalhousie University Identifier: NCT00665964     History of Changes
Other Study ID Numbers: CDHA-RS/2007-249
Study First Received: April 22, 2008
Last Updated: August 10, 2009

Keywords provided by Dalhousie University:
total knee arthroplasty
posterior stabilized

Additional relevant MeSH terms:
Joint Diseases
Musculoskeletal Diseases
Rheumatic Diseases processed this record on July 27, 2017