Cementless Triathlon 5YR Follow-Up

Completed

• Conditions: Radiostereometric Analysis; Knee Osteoarthritis; Knee Arthroplasty, Total
• Interventions: Device: Cementless Total Knee Replacement

• Registration Number: NCT05877261
• Lead Sponsor: London Health Sciences Centre OR Lawson Research Institute of St. Joseph's

Brief Summary

All artificial joint implants need to be solidly held (fixed) within the bone. Cementless fixation has become a popular method to achieve fixation for total knee replacements where the bone grows directly onto the implanted device instead of using bone cement. The primary purpose of this study is to assess long-term implant survivorship and clinical outcomes of a previous study cohort that received a cementless knee replacement. As this study cohort approaches 5 years post-operation, the investigators will re-examine the stability of participant implants using specialized x-rays, called "radiostereometric analysis". The study will use weight-bearing computed tomography (CT) to measure bone density and texture features and correlate that with implant stability. The investigators will collect stool samples to assess participant gut microbiomes for biomarkers of poor bone quality that could correlate to implant stability. All 33 participants from the original study cohort will be invited to participate in this study.

Detailed Description

Not available

Study Timeline

• Study First Submitted: 2023-04-04
• Study First Submitted QC: 2023-05-24
• Study Start: 2023-05-25
• Study First Posted: 2023-05-26
• Primary Completion: 2024-04-01
• Study Completion: 2024-12-31
• Status Verified: 2025-03
• Last Update Submitted: 2025-03-13
• Last Update Posted: 2025-03-17

Recruitment & Eligibility

• Status: COMPLETED
• Sex: All
• Target Recruitment: 18

Inclusion Criteria

• Were in the originally investigated cohort
• Had successful imaging at 1-year post-operation
• Minimum of 5 years post-operation

Exclusion Criteria

• Pregnancy
• Unable to follow-up

Study & Design

• Study Type: OBSERVATIONAL
• Study Design: Not specified

Arm && Interventions

Group	Intervention	Description
Prior Cementless Knee Replacement Cohort	Cementless Total Knee Replacement	Patients who received a cementless knee replacement in 2017-2018 and participated in a prior study measuring the first year of implant migration.

Primary Outcome Measures

Name	Time	Method
Implant Migration (tibial component)	5 year follow-up	Implant movement will be measured with model-based Radiostereometric Analysis (RSA) by registering the location of the tibial component during supine exams. Potential tibial component migration between 1 and 5 years post-operation will be measured in millimeters with the use of tibial bone markers.

Secondary Outcome Measures

Name	Time	Method
Bone Density	5 year follow-up	Weight-bearing computed tomography (CT) scans will be used to measure bone density as Hounsfield units in standardized volumes of interest below the pegs and keel of the tibial component.
Inducible Displacement (RSA-based)	5 year follow-up	Model-based Radiostereometric Analysis (RSA) will be used to register the location of the tibial and femoral components during supine and standing exams. Change in implant position will be measured in millimeters as maximum total point motion (MTPM) between the standing and supine RSA exams.
Implant Migration (femoral component)	5 year follow-up	Implant movement will be measured with model-based Radiostereometric Analysis (RSA) by registering the location of the femoral component during supine exams. Potential femoral component migration between 1 and 5 years post-operation will be measured in millimeters with the use of femoral bone markers.
Inducible Displacement (CT-based)	5 year follow-up	Weight-bearing computed tomography (CT) will be used to register the location of the tibial and femoral components during seated and standing exams. Change in implant position will be measured in millimeters as maximum total point motion (MTPM) between the seated and standing CT exams.
Texture Features	5 year follow-up	Weight-bearing computed tomography (CT) texture analysis will be performed in standardized volumes of interest below the pegs and keel of the tibial component.
Microbial Diversity	5 year follow-up	Participants will provide a stool sample. Microbial DNA will be extracted from the stool samples for 16s rRNA sequencing. Taxonomy will be assigned and functional annotation will be determined.

Trial Locations

Locations (1)

University Hospital; 🇨🇦 London, Ontario, Canada