A Trial of Mechanical Axis With Soft Tissue Release Balancing vs Functional Alignment With Bony Release Balancing in Total Knee Replacement Using Stryker's Mako Robot

July 19, 2024 updated by: Stryker South Pacific

A Prospective, Randomized, Controlled Trial of Mechanical Axis With Soft Tissue Release Balancing vs Functional Alignment With Bony Release Balancing in Total Knee Replacement - A Study Using Stryker Mako Robotic-Arm Assisted Technology®.

This study is a prospective, randomized, longitudinal study of the clinical outcomes of osteoarthritis patients treated by two different alignment philosophies for total knee replacement. All patients will be treated with the same knee system, implanted using MAKO robotic-arm assisted technology.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Active, not recruiting

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.

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.
278

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 Contact

Study Contact

The name and contact information for the person who can answer enrollment questions for a clinical study. Each location where the study is being conducted may also have a specific contact, who may be better able to answer those questions.

Study Locations

  • New Zealand
    • Auckland
      • Takapuna, Auckland, New Zealand, 0622
        • North Shore Hospital

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

36 years to 76 years (Adult, Older Adult)

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  • The patient is a male or non-pregnant female between the ages of 40-80 years.
  • The patient requires a primary total knee replacement and is indicated for robotic-assisted surgery.
  • Patient is deemed appropriate for a cruciate retaining knee replacement.
  • The patient has a primary diagnosis of osteoarthritis (OA).
  • The patient has intact collateral ligaments.
  • The patient is able to undergo CT scanning of the affected limb.
  • The patient has signed the study specific, ethics-approved, Informed Consent document.
  • The patient is willing and able to comply with the specified pre-operative and post-operative clinical and radiographic evaluations.

Exclusion Criteria:

  • The patient has a history of total, unicompartmental reconstruction or fusion of the affected joint.
  • Patient has had a previous osteotomy around the knee.
  • The patient is morbidly obese (BMI ≥ 40).
  • The patient has a deformity which will require the use of stems, wedges or augments in conjunction with the Triathlon Total Knee System.
  • The patient has a varus/valgus deformity ≥ 15°.
  • The patient has a fixed flexion deformity ≥ 15°.
  • The patient has a neuromuscular or neurosensory deficiency, which would limit the ability to assess the performance of the device.
  • The patient has a systemic or metabolic disorder leading to progressive bone deterioration.
  • The patient is immunologically suppressed or receiving steroids in excess of normal physiological requirements.
  • Patient has a cognitive impairment, an intellectual disability or a mental illness.
  • The patient is pregnant.
  • The patient has metal hardware present in the region of the hip, knee or ankle (as this is known to create geometrical distortion in the region of the implant).

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: Double

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: Alignment according to Functional Alignment philosophy
Patients randomized to this group will undergo a TKA (total knee arthroplasty) to receive a Triathlon Total Knee System aligned according to Functional Alignment philosophy. This method of implant alignment is defined by a patient's native joint line as well as the soft tissue envelope. Triathlon Total Knee System components will be positioned relative to intra-operative soft tissue laxity assessment. A mobile application (KneeBalancer) will be used to assist surgeon decision making during the dynamic joint balancing surgical step.
Device: Triathlon® Total Knee System (Stryker Orthopaedics, Mahwah, NJ USA)
All patients, regardless of the alignment arm they are randomized to will undergo a primary total knee arthroplasty with the Triathlon® Total Knee System using Mako Robotic-Arm Assisted Technology. The surgical intervention will be administered by a physician wherein the expected duration of surgery is approximately 1.5 hours.
Active Comparator: Alignment to the patient's natural Mechanical axis
Patients randomized to this group will undergo a TKA (total knee arthroplasty) to receive a Triathlon Total Knee System neutrally aligned to the Mechanical axis. More specifically, the femoral component and tibial component are aligned 0° to the mechanical axis of each respective limb. Femoral component rotation is fixed to the trans-epicondylar axis. Soft tissue releases are performed at the discretion of the surgeon to achieve balance and full range of motion.
Device: Triathlon® Total Knee System (Stryker Orthopaedics, Mahwah, NJ USA)
All patients, regardless of the alignment arm they are randomized to will undergo a primary total knee arthroplasty with the Triathlon® Total Knee System using Mako Robotic-Arm Assisted Technology. The surgical intervention will be administered by a physician wherein the expected duration of surgery is approximately 1.5 hours.

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
Joint feeling and Forgotten Joint Score
Time Frame: Pre-operative (2 weeks prior to surgery), Post-operative - 6 weeks, 6 months, 12 months (primary timepoint) and 24 months
To evaluate differences in joint feeling assessed via the Forgotten Joint Score. This newly-developed 12-item score ranges from 0 to 100 and assesses how aware recipients are of their joint in everyday life. Higher scores indicate a good outcome i.e. a high degree of forgetting the joint. For the purpose of this study a change in score of 14 points for the Forgotten Joint Score has been identified.
Pre-operative (2 weeks prior to surgery), Post-operative - 6 weeks, 6 months, 12 months (primary timepoint) and 24 months

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
Function and Oxford Knee Score
Time Frame: Pre-operative (2 weeks prior to surgery), Post-operative - 6 weeks, 6 months, 12 months and 24 months
To evaluate differences in function between Robotic Assisted Functional Alignment and Robotic Assisted Mechanical Alignment. This will be achieved by employing the following instrument: Oxford Knee Score. This score ranges from 0 to 48 where a higher score indicates a better outcome.
Pre-operative (2 weeks prior to surgery), Post-operative - 6 weeks, 6 months, 12 months and 24 months
Function and The International Knee Society Score
Time Frame: Pre-operative (2 weeks prior to surgery), Post-operative - 6 weeks, 12 months and 24 months
To evaluate differences in function between Robotic Assisted Functional Alignment and Robotic Assisted Mechanical Alignment. This will be achieved by employing the following instrument: The International Knee Society Score. This score ranges from 0 to 100 where a higher score correlates to a better outcome.
Pre-operative (2 weeks prior to surgery), Post-operative - 6 weeks, 12 months and 24 months
Function and Knee Injury and Osteoarthritis Outcome Score
Time Frame: Pre-operative (2 weeks prior to surgery), Post-operative - 6 weeks, 6 months, 12 months and 24 months
To evaluate differences in function between Robotic Assisted Functional Alignment and Robotic Assisted Mechanical Alignment. This will be achieved by employing the following instrument: Knee Injury and Osteoarthritis Outcome Score. This score ranges from 0 to 100 where 0 indicates the worst possible knee symptoms and 100 signifies no knee symptoms.
Pre-operative (2 weeks prior to surgery), Post-operative - 6 weeks, 6 months, 12 months and 24 months
Pain and Oxford Knee Score
Time Frame: Pre-operative (2 weeks prior to surgery), Post-operative - 6 weeks, 6 months, 12 months and 24 months
To evaluate differences in pain between Robotic Assisted Functional Alignment and Robotic Assisted Mechanical Alignment. This will be achieved by employing the following instrument: Oxford Knee Score. This score ranges from 0 to 48 where a higher score indicates a better outcome.
Pre-operative (2 weeks prior to surgery), Post-operative - 6 weeks, 6 months, 12 months and 24 months
Pain and The International Knee Society Score
Time Frame: Pre-operative (2 weeks prior to surgery), Post-operative - 6 weeks, 12 months and 24 months
To evaluate differences in pain between Robotic Assisted Functional Alignment and Robotic Assisted Mechanical Alignment. This will be achieved by employing the following instrument: The International Knee Society Score. This score ranges from 0 to 100 where a higher score correlates to a better outcome.
Pre-operative (2 weeks prior to surgery), Post-operative - 6 weeks, 12 months and 24 months
Pain and Knee Injury and Osteoarthritis Outcome Score
Time Frame: Pre-operative (2 weeks prior to surgery), Post-operative - 6 weeks, 6 months, 12 months and 24 months
To evaluate differences in pain between Robotic Assisted Functional Alignment and Robotic Assisted Mechanical Alignment. This will be achieved by employing the following instrument: Knee Injury and Osteoarthritis Outcome Score. This score ranges from 0 to 100 where 0 indicates the worst possible knee symptoms and 100 signifies no knee symptoms.
Pre-operative (2 weeks prior to surgery), Post-operative - 6 weeks, 6 months, 12 months and 24 months
Pain and Visual Analogue Scale
Time Frame: Pre-operative (2 weeks prior to surgery), Post-operative - 6 weeks, 6 months, 12 months and 24 months
To evaluate differences in pain between Robotic Assisted Functional Alignment and Robotic Assisted Mechanical Alignment. This will be achieved by employing the following graphic measurement instrument: Visual Analogue Scale. This scale is a continuum between no pain and the worst possible pain imaginable.
Pre-operative (2 weeks prior to surgery), Post-operative - 6 weeks, 6 months, 12 months and 24 months
Satisfaction and Net Promoter Score
Time Frame: Pre-operative (2 weeks prior to surgery), Post-operative - 6 weeks, 6 months, 12 months and 24 months
To evaluate differences in satisfaction between Robotic Assisted Functional Alignment and Robotic Assisted Mechanical Alignment. This will be achieved by employing the following instrument: Net Promoter. This score ranges from -100 to 100 where the upper end indicates the patient's recommendation of the healthcare they received.
Pre-operative (2 weeks prior to surgery), Post-operative - 6 weeks, 6 months, 12 months and 24 months
Health related quality of life and Euro-Qol (EQ-5D-3L)
Time Frame: Pre-operative (2 weeks prior to surgery), Post-operative - 6 weeks, 6 months, 12 months and 24 months
To evaluate differences in health-related quality of life between Robotic Assisted Functional Alignment and Robotic Assisted Mechanical Alignment. This will be achieved by employing the following instrument: Euro-Qol (EQ-5D-3L). This score ranges from 0 to 100 where 0 correlates to the worst imaginable health state whilst 100 indicates the best.
Pre-operative (2 weeks prior to surgery), Post-operative - 6 weeks, 6 months, 12 months and 24 months
Early pain
Time Frame: In-patient setting (< 5 days post-operation), Post-operative - 6 weeks and 6 months
To evaluate differences in early pain (i.e. from in-patient setting to 6-months post operation) between Robotic Assisted Functional Alignment and Robotic Assisted Mechanical Alignment. This objective will be achieved through the use of a patient pain inventory form.
In-patient setting (< 5 days post-operation), Post-operative - 6 weeks and 6 months
Early function
Time Frame: In-patient setting (< 5 days post-operation)
To evaluate differences in early function between Robotic Assisted Functional Alignment and Robotic Assisted Mechanical Alignment. This objective will be achieved by utilizing functional tests conducted by physiotherapists. The following functional test will be carried out on the knee joint: Range of motion
In-patient setting (< 5 days post-operation)
Early function
Time Frame: In-patient setting (< 5 days post-operation)
To evaluate differences in early function between Robotic Assisted Functional Alignment and Robotic Assisted Mechanical Alignment. This objective will be achieved by utilizing functional tests conducted by physiotherapists. The following functional test will be employed: 9 step stair climb
In-patient setting (< 5 days post-operation)
Early function
Time Frame: In-patient setting (< 5 days post-operation)
To evaluate differences in early function between Robotic Assisted Functional Alignment and Robotic Assisted Mechanical Alignment. This objective will be achieved by utilizing functional tests conducted by physiotherapists. The following functional test will be employed: fast paced 10m walk test
In-patient setting (< 5 days post-operation)
Early function
Time Frame: In-patient setting (< 5 days post-operation)
To evaluate differences in early function between Robotic Assisted Functional Alignment and Robotic Assisted Mechanical Alignment. This objective will be achieved by utilizing functional tests conducted by physiotherapists. The following functional test will be employed: 30 second chair stand test
In-patient setting (< 5 days post-operation)
Blood loss
Time Frame: Intra-operative
To compare blood loss between Robotic Assisted Functional Alignment and Robotic Assisted Mechanical Alignment. This objective will be achieved through obtaining surgical data.
Intra-operative
Adjustments to balance
Time Frame: Intra-operative
To compare adjustments to balance between Robotic Assisted Functional Alignment and Robotic Assisted Mechanical Alignment. This objective will be achieved through obtaining the position from the Robotic system.
Intra-operative
Ability to reach target knee balance as assessed by alignment angles and gaps
Time Frame: Pre-operative (2 weeks prior to surgery), intra-operative, Post-operative - 6 weeks, 12 months and 24 months
To compare the ability to achieve soft tissue balance between Robotic Assisted Functional Alignment and Robotic Assisted Mechanical Alignment. This object will be achieved by comparing pre-operative plan and pre-resection gaps with the final surgical plan and implanted gaps as derived from the robotic system. The implant position is defined as the angulation of components and resected bone in each anatomical plane. The soft tissue balance is defined as gaps created in extension and 90° of flexion when stressing the medial compartment (medial collateral ligament) and lateral compartment (lateral collateral ligament). The overall limb alignment is assessed by comparing the Hip-Knee-Ankle angle from pre-operative to 1-year post-operative on a long leg weight bearing x-ray.
Pre-operative (2 weeks prior to surgery), intra-operative, Post-operative - 6 weeks, 12 months and 24 months

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.
Stryker South Pacific

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: Simon Young, Dr, North Shore Hospital

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

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.
November 12, 2020

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.
December 20, 2023

Study Completion (Estimated)

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.
March 1, 2025

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).
September 29, 2020

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.
October 19, 2020

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.
October 23, 2020

Study Record Updates

Last Update Posted (Actual)

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.
July 23, 2024

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.
July 19, 2024

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.
July 1, 2024

More Information

Terms related to this study

Keywords

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.
  • CAMELOT

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

Yes

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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Drug Interventions

Conditions

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Drug Interventions

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