Triathlon All-Polyethylene Tibia Outcomes Study (APT)

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.

Study Overview

• Status: Active, not recruiting
• Conditions: Knee Arthritis; Arthropathy of Knee; Replacement
• Intervention / Treatment: Device: Triathlon All-Polyethylene Tibia Knee

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 Type: Interventional
• Enrollment (Actual): 204
• Phase: Not Applicable

Contacts and Locations

Study Locations

• United States
  • Michigan
    • Lansing, Michigan, United States, 48910
      • Michigan Orthopaedic Center
  • New York
    • Buffalo, New York, United States, 14203
      • Kaleida Health, Department of Orthopaedic Surgery, Buffalo General Hospital
    • Syracuse, New York, United States, 13214
      • Syracuse Orthopedic Specialists, PC
  • North Carolina
    • Durham, North Carolina, United States, 27703
      • Duke University Medical Center
  • Ohio
    • Cleveland, Ohio, United States, 44195
      • Department of Orthopaedic Surgery Cleveland Clinic
  • Texas
    • Austin, Texas, United States, 78712
      • Musculoskeletal Institute, University of Texas Health Austin

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years and older (Adult, Older Adult)
• Accepts Healthy Volunteers: No

Description

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.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: N/A
• Interventional Model: Single Group Assignment
• Masking: None (Open Label)

Number of Arms

1

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Other: Triathlon All-Polyethylene Tibia Knee; All subjects enrolled will have received the Triathlon All-Polyethylene Tibia Knee device.	Device: Triathlon All-Polyethylene Tibia Knee; Triathlon All-Polyethylene Tibia Knee is an all polyethylene resurfacing knee device using either a condylar stabilizing (CS) and posterior stabilizing (PS) device.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
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.	10-years postoperative

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Kaplan-Meier Survival Analysis	To present 10-year Kaplan-Meier survival analysis for the Triathlon APT	10-years postoperative

Collaborators and Investigators

• Sponsor: Stryker Orthopaedics

Study record dates

Study Major Dates

• Study Start (Actual): July 2, 2021
• Primary Completion (Estimated): October 1, 2033
• Study Completion (Estimated): October 1, 2033

Study Registration Dates

• First Submitted: November 13, 2020
• First Submitted That Met QC Criteria: November 13, 2020
• First Posted (Actual): November 19, 2020

Study Record Updates

• Last Update Posted (Actual): February 27, 2026
• Last Update Submitted That Met QC Criteria: February 24, 2026
• Last Verified: February 1, 2026

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Musculoskeletal Diseases; Joint Diseases
• Other Study ID Numbers: 104

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