Patient Outcomes Following Kinematic and Functional Alignment in Robotic-Assisted Total Knee Arthroplasty With Randomized Insert Types (VELYS RCT)

April 16, 2026 updated by: Lincoln Liow Ming Han, Singapore General Hospital

A Prospective Randomized Controlled Trial Comparing Patient Outcomes Following Kinematic and Functional Alignment in Robotic-Assisted Total Knee Arthroplasty Using the VELYS System

This study aims to evaluate patient outcomes following robotic-assisted total knee arthroplasty using the VELYS system. Patients undergoing surgery will receive either kinematic alignment or functional alignment as determined by the operating surgeon as part of routine clinical care. Within each surgical technique group, patients will be randomly assigned to receive different implant insert types (medial stabilised or cruciate retaining) using a REDCap-based randomisation process. Patient-reported outcome measures will be collected before surgery and at follow-up time points after surgery to assess clinical outcomes.

Study Overview

Detailed Description

This is a prospective interventional study evaluating outcomes in patients undergoing robotic-assisted total knee arthroplasty using the VELYS system. The study includes patients treated using either kinematic alignment or functional alignment techniques, which are determined by the operating surgeon based on clinical practice and are not randomized as part of the study protocol.

Within each alignment group, participants are randomized to receive one of two implant insert types: medial stabilised (MS) or cruciate retaining (CR). Randomisation is performed using a REDCap-based allocation system.

The primary objective of the study is to assess patient-reported outcomes following surgery. Secondary outcomes may include clinical and functional measures collected at predefined time points, including pre-operative and post-operative follow-up visits.

This study reflects real-world clinical practice while incorporating a randomized component for implant selection. The design allows for evaluation of both implant-related outcomes and comparisons across different alignment techniques, while maintaining clarity regarding which aspects of the intervention are randomized.

Study Type

Interventional

Enrollment (Estimated)

240

Phase

  • 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

      • Singapore, Singapore
        • Recruiting
        • Singapore General Hospital
        • Contact:
        • Principal Investigator:
          • Lincoln Ming Han Liow, MBBS

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

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Description

*Inclusion Criteria:*

  • Patients undergoing robotic-assisted total knee arthroplasty using the VELYS system
  • Diagnosis of knee osteoarthritis requiring surgical intervention
  • Able to provide informed consent
  • Willing to complete patient-reported outcome measures

**Exclusion Criteria:**

  • Patients undergoing revision knee arthroplasty
  • Presence of active infection
  • Inability to comply with follow-up assessments
  • Severe co-morbidities that may affect surgical outcomes or participation in the study

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: None (Open Label)

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: Kinematic Alignment + Medial Stabilized Insert
Patients undergoing kinematic alignment with medial stabilised insert in robotic-assisted total knee arthroplasty.
A medial stabilised polyethylene insert used in robotic-assisted total knee arthroplasty to provide enhanced stability during knee motion.
Other Names:
  • MS insert
Experimental: Kinematic Alignment + Cruciate Retaining Insert
Patients undergoing kinematic alignment with cruciate retaining insert in robotic-assisted total knee arthroplasty
A cruciate retaining polyethylene insert used in robotic-assisted total knee arthroplasty that preserves the posterior cruciate ligament.
Experimental: Functional Alignment + Medial Stabilized Insert
Patients undergoing functional alignment with medial stabilised insert in robotic-assisted total knee arthroplasty.
A medial stabilised polyethylene insert used in robotic-assisted total knee arthroplasty to provide enhanced stability during knee motion.
Other Names:
  • MS insert
Experimental: Functional Alignment + Cruciate Retaining Insert
Patients undergoing functional alignment with cruciate retaining insert in robotic-assisted total knee arthroplasty
A cruciate retaining polyethylene insert used in robotic-assisted total knee arthroplasty that preserves the posterior cruciate ligament.

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Forgotten Joint Score (FJS)
Time Frame: Pre-operative, 6 weeks, 6 months, and 2 years post-operatively
Forgotten Joint Score (FJS) The Forgotten Joint Score (FJS) is a patient-reported outcome measure assessing joint awareness in daily life following total knee arthroplasty. The score ranges from 0 to 100, with higher scores indicating better outcomes (less joint awareness).
Pre-operative, 6 weeks, 6 months, and 2 years post-operatively

Collaborators and Investigators

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

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)

October 14, 2025

Primary Completion (Estimated)

October 14, 2027

Study Completion (Estimated)

October 14, 2027

Study Registration Dates

First Submitted

April 9, 2026

First Submitted That Met QC Criteria

April 9, 2026

First Posted (Actual)

April 16, 2026

Study Record Updates

Last Update Posted (Actual)

April 21, 2026

Last Update Submitted That Met QC Criteria

April 16, 2026

Last Verified

April 1, 2026

More Information

Terms related to this study

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

UNDECIDED

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

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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