Trial Comparing Alignment Techniques - RSA of ATTUNE Knee System

December 3, 2025 updated by: Canadian Radiostereometric Analysis Network

Radiostereometric Analysis (RSA) of the ATTUNE Knee System: A Randomized Controlled Trial Comparing Anatomic (Femur First) to Neutral Mechanical Alignment Techniques

The purpose of this study is to compare migration patterns between mechanical and anatomic alignment surgical techniques for the Attune S+ CR-FB knee system using model-based RSA over the first 2 post-operative years.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Completed

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.

Detailed Description

This is a multi-centre, randomized controlled trial of patients undergoing cruciate-retaining total knee arthroplasty with the Attune S+ fixed bearing TKR system. Patients will be randomized to two study groups:

  1. Neutral mechanical alignment;
  2. Anatomical alignment.

The principal objective of this study is to compare migration patterns between mechanical and anatomic alignment surgical techniques for the Attune S+ CR-FB knee system using model-based RSA over the first 2 post-operative years.

Secondary objectives include; comparison of 2-year migration values against published thresholds for adequate short-term fixation, comparison of functional and health status of subjects following surgery, comparison of intra-operative soft-tissue releases, incidence of complications and adverse events, and to assess several health economic parameters relating to the surgery.

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Interventional

Enrollment (Actual)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
52

Phase

Phase

The stage of a clinical trial studying a drug or biological product, based on definitions developed by the U.S. Food and Drug Administration (FDA). The phase is based on the study's objective, the number of participants, and other characteristics. There are five phases: Early Phase 1 (formerly listed as Phase 0), Phase 1, Phase 2, Phase 3, and Phase 4. Not Applicable is used to describe trials without FDA-defined phases, including trials of devices or behavioral interventions.
  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

  • Canada
    • Manitoba
      • Winnipeg, Manitoba, Canada, R2K 3S8
        • Concordia Hospital
    • Ontario
      • London, Ontario, Canada, N6A 5W9
        • London Health Sciences Centre

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

21 years to 80 years (Adult, Older Adult)

Accepts Healthy Volunteers

Yes

Description

Inclusion Criteria:

  1. Symptomatic osteoarthritis of the knee indicating primary total knee arthroplasty
  2. Varus knee deformity of 0 to 10 degrees
  3. Sufficient ligamentous function to warrant retention of the posterior cruciate ligament
  4. Between the ages of 21 and 80 inclusive
  5. Patients willing and able to comply with follow-up requirements and self-evaluations
  6. Ability to give informed consent

Exclusion Criteria:

  1. Active or prior infection
  2. Medical condition precluding major surgery
  3. Inflammatory arthropathy
  4. Prior patellectomy
  5. PCL deficiency
  6. Major Coronal plane deformity
  7. Valgus alignment
  8. Bone defects requiring augments, cones and/or stemmed implants
  9. Body Mass Index 45 or more

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Treatment
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: Single

Arms and Interventions

Participant Group / Arm

Participant Group / Arm

A group or subgroup of participants in a clinical trial that receives a specific intervention/treatment, or no intervention, according to the trial's protocol.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
Active Comparator: Neutral Mechanical Alignment
Total knee arthroplasty: Neutral Mechanical Alignment vs Anatomical Alignment
Procedure: Neutral Mechanical Alignment
Hip-knee-ankle angle of 180° ± 3°.
Active Comparator: Anatomical Alignment
Total knee arthroplasty: Neutral Mechanical Alignment vs Anatomical Alignment
Procedure: Anatomical Alignment
Restoring a patient's pre-diseased limb alignment

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Measure Description
Time Frame
Implant migration
Time Frame: 2 years
Measured via radiosteriometric analysis (RSA)
2 years

Secondary Outcome Measures

Secondary Outcome Measures

In a clinical study's protocol, a planned outcome measure that is not as important as the primary outcome measure for evaluating the effect of an intervention but is still of interest. Most clinical studies have more than one secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
Hospital stay
Time Frame: Up to 1 week
Number of days in hospital
Up to 1 week
Oxford-12 knee score
Time Frame: Pre-operative, 6 weeks, 3 months, 6 months, 1 year, 2 years
The Oxford Knee Score (OKS) is a patient self-administered 12-item questionnaire with each question having a Likaert-like response option. Each item is scored from 0 to 4, and the items are summated, with lower total scores indicating poorer performance. The OKS measures pain and general activities of daily living.
Pre-operative, 6 weeks, 3 months, 6 months, 1 year, 2 years
Pain Catastrophizing Scale (PCS)
Time Frame: Pre-operative, 12 months
The patient are asked to indicate the degree to which they have the above thoughts and feelings when they are experiencing pain. Each PCS item is rated on a 5-point scale: 0 (not at all) to 4 (all the time). The PCS total score is computed by summing responses to the 13 items. PCS total scores range from 0 - 52.
Pre-operative, 12 months
European Quality of Life (EQ-5D-5L)
Time Frame: Pre-operative, 6 weeks, 3 months, 6 months, 1 year, 2 years
Evaluate and compare the change from preoperative to 2 years between the study groups timepoints in functional outcomes assessments. The EuroQol 5D 5L questionnaire is a standardized instrument for use as a measure of generic health status - completed by the subject. The EQ5D uses a Likert scale which assesses five states (mobility, self care, usual care, pain and discomfort and anxiety and depression) at five different levels - none(0), slight(1), moderate(2), severe(3) or unable to perform(5). Levels are coded 1-5 and an index score is then generated.
Pre-operative, 6 weeks, 3 months, 6 months, 1 year, 2 years
Pre-operative Patient's Knee Implant Performance (PKIP)
Time Frame: Pre-operative, 6 weeks, 3 months, 6 months, 1 year, 2 years
The Pre-surgical and/or Post-surgical Patient's Knee Implant Performance (PKIP) questionnaire is a patient reported questionnaire that consists of 24 questions relating to the patient's awareness of their knee. Questions include the patient's self-confidence about the current status of their knee performance, stability, and overall satisfaction. Each question has a 5, 6 or 10 Likaert- like response option.
Pre-operative, 6 weeks, 3 months, 6 months, 1 year, 2 years
7. University of California at Los Angeles (UCLA) Activity Level scale
Time Frame: Pre-operative, 6 months, 1 year, 2 years
Evaluate and compare the change in UCLA activity score compared to baseline in the study cohort. UCLA activity scores range from 1 to 10, and is a measure of activity with 10 being most active.
Pre-operative, 6 months, 1 year, 2 years
Pain VAS
Time Frame: Preoperative, 6 Weeks, 3 Months, 6 Months, 1 Year, 2 Years
Evaluate and compare the change from preoperative to 2 years between the study groups timepoints in patient reported satisfaction as measured using the visual analogue scale (VAS) from 0 (No pain) - 100 (Worst pain imaginable)
Preoperative, 6 Weeks, 3 Months, 6 Months, 1 Year, 2 Years
Patient satisfaction: VAS
Time Frame: Preoperative, 3 Months, 6 Months, 1 Year, 2 Years
Evaluate and compare the change from preoperative to 2 years between the study groups timepoints in patient reported pain severity as measured using the visual analogue scale (VAS) from 0 (Unsatisfied) - 100 (Completely satisfied)
Preoperative, 3 Months, 6 Months, 1 Year, 2 Years
Patient complications
Time Frame: Preoperative, 6 Weeks, 3 Months, 6 Months, 1 Year, 2 Years
Evaluate the type and frequency of the complications/adverse events.
Preoperative, 6 Weeks, 3 Months, 6 Months, 1 Year, 2 Years
Tourniquet time
Time Frame: Intraoperative
Length of time tourniquet was applied (minutes)
Intraoperative
Length of surgery
Time Frame: Intraoperative
Length of surgery, from open to closing of incision (minutes)
Intraoperative
Blood loss
Time Frame: Intraoperative
Amount of blood loss during the procedure (mL)
Intraoperative
Anesthesia type
Time Frame: Intraoperative
Anesthesia methods (general, spinal, epidural, TXA)
Intraoperative
Peri-operative pain management
Time Frame: Intraoperative
A tabulation of the pain management (Peri-Articular Injection, Femoral Nerve Block, Add. Canal Block or none) used during the procedure.
Intraoperative
Soft tissue release
Time Frame: Intraoperative
A tabulation of the tissue released during the procedure (MCL, LCL, PCL, Posterior Capsule Release).
Intraoperative

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
Canadian Radiostereometric Analysis Network

Investigators

Investigators

A researcher involved in a clinical study. Related terms include site principal investigator, site sub-investigator, study chair, study director, and study principal investigator.
  • Principal Investigator: Thomas Turgeon, Concordia Joint Replacement Group

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
May 5, 2019

Primary Completion (Actual)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
February 1, 2022

Study Completion (Actual)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
February 1, 2022

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
July 17, 2019

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
September 4, 2019

First Posted (Actual)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
September 6, 2019

Study Record Updates

Last Update Posted (Estimated)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
December 4, 2025

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
December 3, 2025

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
December 1, 2025

More Information

Terms related to this study

Additional Relevant MeSH Terms

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • B2018-139

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

product manufactured in and exported from the U.S.

Yes

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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