Arthropathy of KneeAPTNCT04636190
Triathlon All-Polyethylene Tibia Outcomes Study
A study testing Triathlon All-Polyethylene Tibia Knee in people with Arthropathy of Knee and Replacement, run by Stryker Orthopaedics at 6 sites in United States.
Trial summary
The purpose of this study is to evaluate the clinical functional results of the Triathlon All-Polyethylene Tibia Knee Device. Read more about this study
- Who is it for?
- Ages 18 years and older
- Conditions the study is for
- Arthropathy of Knee, Replacement, Knee Arthritis
- What is being tested?
- Triathlon All-Polyethylene Tibia Knee
- Type of treatment
- Medical device
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 204 participants
- Where
- 6 sitesUnited States
- Study dates
- 2 Jul 2021to Oct 2033
- Phase
- Interventional
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 years and older
- All sexes
- No healthy volunteers
- Adult, Older adult
Inclusions:
- Patient underwent primary TKA and is currently implanted with the Triathlon All-Polyethylene Tibia as well as compatible Stryker femoral and patellar components with no pending revision or removal.
- Patient has signed an IRB-approved, study specific Informed Patient Consent Form.
- Patient is a male or non-pregnant female and is 18 years of age or older at the time of study device implantation.
- Patient is willing and able to comply with postoperative scheduled clinical and radiographic evaluations.
Exclusions:
- Patient had an active or suspected latent infection in or about the affected knee joint at time of study device implantation.
- Patient had distant foci of infection which could have caused hematogenous spread to the implant site at time of study device implantation.
- Patient was skeletally immature at time of study device implantation.
- Patient has a mental or neuromuscular disorder which would create an unacceptable risk of prosthesis instability, prosthesis fixation failure, or complications in postoperative care.
- Patient's bone stock was compromised by disease, infection, or prior implantation which cannot provide adequate support and/or fixation to the prosthesis.
- Patient had severe instability of the knee joint secondary to the absence of collateral ligament integrity and function.
- Patient was immunologically suppressed or receiving steroids in excess of normal physiological requirements at the time of surgery (e.g. > 30 days duration of treatment).
- Patient is a prisoner.
Trial locations and contacts
6 sites in 1 country.
6 sites in 1 country
United States6 sites
Musculoskeletal Institute, University of Texas Health Austin
Austin, Texas, 78712
Kaleida Health, Department of Orthopaedic Surgery, Buffalo General Hospital
Buffalo, New York, 14203
Department of Orthopaedic Surgery Cleveland Clinic
Cleveland, Ohio, 44195
Duke University Medical Center
Durham, North Carolina, 27703
Michigan Orthopaedic Center
Lansing, Michigan, 48910
Syracuse Orthopedic Specialists, PC
Syracuse, New York, 13214
About this study
Official title: A Retrospectively Enrolled and Prospectively Followed, Post-market, Multi-center Evaluation of the Clinical Outcomes of the Triathlon All-Polyethylene Tibia
The purpose of this study is to evaluate the clinical functional results of the Triathlon All-Polyethylene Tibia Knee Device.
Read the detailed description
This study is a retrospectively enrolled, prospective evaluation of the Triathlon All-Polyethylene Tibia (APT) for patients who meet the eligibility criteria. The enrolled cases will be followed for outcomes measured to 10 years. A modular, Triathlon metal-backed tibia (MBT) and polyethylene insert construct will be used as a historical control.
- Conditions
- Arthropathy of Knee, Replacement, Knee Arthritis
- Being tested
- Triathlon All-Polyethylene Tibia Knee
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Triathlon All-Polyethylene Tibia KneeDevice
Triathlon All-Polyethylene Tibia Knee is an all polyethylene resurfacing knee device using either a condylar stabilizing (CS) and posterior stabilizing (PS) device.
| Study group | Role | What they receive |
|---|---|---|
| Triathlon All-Polyethylene Tibia Knee | Other | All subjects enrolled will have received the Triathlon All-Polyethylene Tibia Knee device. Receives: Device: Triathlon All-Polyethylene Tibia Knee |
What is being measured
The primary outcome is the main question the study is designed to answer.
Knee Society Score (KSS) Function
The Knee Society Clinical Rating System is comprised of two distinct sub-scores: one for pain, range of motion (ROM) and joint stability, and one for functional parameters. Sub-scores range from a potential minimum score of 0 to a maximum score of 100 points. Although the specific scores are not distinguished as "excellent," "good," "fair," or "poor," a higher value represents a better outcome postoperative.
Measured: 10-years postoperative
Secondary outcomes (1)
Kaplan-Meier Survival Analysis
To present 10-year Kaplan-Meier survival analysis for the Triathlon APT
Measured: 10-years postoperative
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted19 Nov 2020
- Study start2 Jul 2021
- Primary completionOct 2033 (estimated)
- Study completionOct 2033 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Arthropathy of KneeStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Treatment
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Enrolment
- 204 participants (actual)
Sponsor and investigators
- Lead sponsor
- Stryker Orthopaedics
- Sponsor type
- Industry (pharma, biotech, devices)
- Responsible party
- Sponsor
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT04636190
- Sponsor's protocol ID
- 104
- Acronym
- APT
- Status last verified
- Feb 2026
- First submitted
- 13 Nov 2020
- Last updated
- 27 Feb 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- Yes
Study at a glance
From the registry record, last updated by the sponsor on 27 Feb 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- A Retrospectively Enrolled and Prospectively Followed, Post-market, Multi-center Evaluation of the Clinical Outcomes of the Triathlon All-Polyethylene Tibia
- ClinicalTrials.gov ID
- NCT04636190
- Acronym / sponsor ID
- APT / 104
- Conditions
- Arthropathy of Knee, Replacement, Knee Arthritis
- Study type
- Interventional
- Recruitment status
- Active, not recruiting
- Enrolment
- 204 participants (actual)
- Lead sponsor
- Stryker OrthopaedicsIndustry (pharma, biotech, devices)
- Study start
- 2 Jul 2021 (actual)
- Primary completion
- Oct 2033 (estimated)
- Study completion
- Oct 2033 (estimated)
- First posted
- 19 Nov 2020 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
The purpose of this study is to evaluate the clinical functional results of the Triathlon All-Polyethylene Tibia Knee Device.
Detailed description
This study is a retrospectively enrolled, prospective evaluation of the Triathlon All-Polyethylene Tibia (APT) for patients who meet the eligibility criteria. The enrolled cases will be followed for outcomes measured to 10 years. A modular, Triathlon metal-backed tibia (MBT) and polyethylene insert construct will be used as a historical control.
Study design
- Primary purpose
- Treatment
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Number of arms
- 1
| Arm | Type | Receives |
|---|---|---|
| Triathlon All-Polyethylene Tibia Knee | Other | Device: Triathlon All-Polyethylene Tibia KneeAll subjects enrolled will have received the Triathlon All-Polyethylene Tibia Knee device. |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Triathlon All-Polyethylene Tibia KneeTriathlon All-Polyethylene Tibia Knee is an all polyethylene resurfacing knee device using either a condylar stabilizing (CS) and posterior stabilizing (PS) device. | Device | Triathlon All-Polyethylene Tibia Knee |
Primary outcome
Knee Society Score (KSS) Function
Time frame: 10-years postoperative
The Knee Society Clinical Rating System is comprised of two distinct sub-scores: one for pain, range of motion (ROM) and joint stability, and one for functional parameters. Sub-scores range from a potential minimum score of 0 to a maximum score of 100 points. Although the specific scores are not distinguished as "excellent," "good," "fair," or "poor," a higher value represents a better outcome postoperative.
1 secondary outcome
Kaplan-Meier Survival Analysis
Time frame: 10-years postoperative
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 27 Feb 2026.
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
The record lists no contact. Use the official record to reach the sponsor.
6 sites in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Triathlon All-Polyethylene Tibia Knee in people with Arthropathy of Knee and Replacement, run by Stryker Orthopaedics at 6 sites in United States.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: under way, not looking for participants, as of the sponsor's last update on 27 Feb 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 6 sites in United States. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Knee Society Score (KSS) Function (time frame: 10-years postoperative). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 27 Feb 2026.