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RecruitingNCT05863741Updated Sep 29, 2025

Clinical Utility and Gait Analysis of NextAR System AUS

An observational study in Total Knee Arthroplasty, sponsored by Medacta International SA. Recruiting at 1 site in Australia. Open to participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2025-09-29.

Sponsored by Medacta International SA · Observational

Study type
Observational
Model
Case-control
Time perspective
Prospective
Enrollment
100
Ages
18 Years and older
Sex
All
01

Study summary

This study titled "Does Personalised Soft Tissue Balance Data Improve Outcomes in Patients Undergoing Medially Stabilised Arthroplasty? A Prospective, Randomised Study Investigating the Clinical Utility of the NextAR navigation system (NextAR)" is a randomised, single blinded, prospective cohort study with the primary aim determine the clinical utility of the NextAR system data in providing soft tissue balance patterns to enable prosthesis implants to resemble more native knee alignment.

Read the detailed description

This study titled "Does Personalised Soft Tissue Balance Data Improve Outcomes in Patients Undergoing Medially Stabilised Arthroplasty? A Prospective, Randomised Study Investigating the Clinical Utility of the NextAR navigation system (NextAR)" is a randomised, single blinded, prospective cohort study with the primary aim determine the clinical utility of the NextAR system data in providing soft tissue balance patterns to enable prosthesis implants to resemble more native knee alignment.

The aims of this study are:

  • To determine the clinical utility of the NextAR system data in providing soft tissue balance patterns to enable prosthesis implants to resemble more native knee alignment
  • To determine whether NextAR system data contributes to improving patient outcomes and knee kinematics following TKR surgery, by providing greater flexion range that is equivalent to native knee motion.
  • To assess clinical outcomes measured by standardised assessments, including radiographic evidence, the Forgotten Joint Score (FJS), the Oxford Knee Score (OKS), International Knee Documentation Committee (IKDC) and European Quality of Life Five Dimensions - Five Levels (EQ5D-5L) questionnaires.
  • Determining the kinematics of the replaced knee as measured by 3D gait analysis.

According to study protocol, clinical evaluation is performed preoperatively and postoperatively at 6 weeks, 6 months, 1, and 2 years with the use of the Forgotten Joint Score (FJS), Oxford Knee Score (OKS), International Knee Documentation Committee (IKDC) and European Quality of Life Five Dimensions - Five Levels (EQ5D-5L).

CT scan is performed preoperatively and at 6-weeks after surgery, while X-ray assessment is performed at baseline and at the 1-year follow up.

02

Conditions studied

  • Total Knee Arthroplasty
03

Who can participate

Ages eligible
18 Years and older
Sexes eligible
All
Accepts healthy volunteers
No
Sampling method
Probability sample

Study population

The trial will include two groups of 50 patients in each group. This is based on a power calculation assuming a difference in Forgotten Join Score of greater than 5 points. This calculation allows for a loss to follow-up of 10%. The study will conclude once the patients involved have completed 2 years of follow-up.

Inclusion criteria

  • End-stage osteoarthritis of the knee suitable for total knee arthroplasty.
  • Aged over 18 years.

Exclusion criteria

Exclusion Criteria:

  • Unsuitable for TKR due to chronic infection, medical disease, inability to consent, inability to attend for post-operative follow-up, significant psychiatric issues, substance abuse issues
  • Previous reconstructive/fracture/arthroplasty surgery on affected knee
  • Active inflammation arthropathy
  • Significant extra articular deformity
  • Morbidly Obese (BMI >40)
  • Pregnant women
04

Study design

Observational model
Case-control
Time perspective
Prospective
Enrollment
100 participants (estimated)
Patient registry
No

Groups and cohorts

  • control study

    patients will be operated with conventional instrumentation

    Device: Implantation of GMK Sphere with conventional instrumentation

  • NextAR study

    patients will be operated using the NextAR guidance system

    Device: Implantation of GMK Sphere using the NextAR guidance system

Interventions

  • DeviceImplantation of GMK Sphere with conventional instrumentation

    Implantation of GMK Sphere with conventional instrumentation (control group)

  • DeviceImplantation of GMK Sphere using the NextAR guidance system

    Implantation of GMK Sphere using the NextAR guidance system (NextAR group)

05

What researchers measure

Primary outcomes

  1. Determine whether NextAR system data contributes to change patient outcomes using the Forgotten Joint Score

    To determine whether NextAR system data contributes to change patient outcomes using the Forgotten Joint Score \- Forgotten Joint Score measures the patient's ability to forget about the joint as a result of successful treatment and is based on the premise that the best arthroplasty is one the patient forgets. This score goes from a minimum of 0 to a maximum of 100 points.

    Time frame: pre-op, 6 weeks, 6 months, 1 year, 2 years

Secondary outcomes

  1. To determine whether NextAR system data contributes to change patient outcomes using the EQ5D-5L

    To determine whether NextAR system data contributes to change patient outcomes using the EQ5D-5L The EQ5D-5L comprises of 6 questions survey that measures generic health-related quality of life. This score goes from a minimum of 0 to a maximum of 1 points.

    Time frame: pre-op, 6 weeks, 6 months, 1 year, 2 years

  2. Determining the kinematics of the replaced knee as measured by 3D gait analysis.

    The purpose of the gait analysis will be to assess the variation in kinematics between the patients replaced knee (in both study groups) compared to normal knee kinematic data reported in the literature. The hypothesis being tested is that alteration of component position to give more normal ligament tension, will more resemble normal knee kinematics. (n=20) will be sufficient to conduct the gait analysis. These patients will be selected from the overall cohort for enrolment at 12 months post-surgery and matched for age, gender, BMI and osteoarthritis pattern. The comparison will involve comparing the average kinematic data values obtained in group 1 (NextAR data provided at surgery) vs the reported values in the literature and the same analysis will be repeated for patients in group 2 (NextAR data not provided at surgery).comparison will be made between the two groups in terms of which more closely replicates the kinematics of the non-arthritic knee

    Time frame: pre-op, 1 year

  3. To determine whether NextAR system data contributes to change patient outcomes using the Oxford Knee Score

    To determine whether NextAR system data contributes to change patient outcomes using the Oxford Knee Score the Oxford Knee Score is a questionnaire that has been specifically developed to assess knee function and pain. It is short, reproducible and extensively referenced in orthopaedic literature, making it a preferred tool for studies. This score goes from a minimum of 0 to a maximum of 48 points.

    Time frame: pre-op, 6 weeks, 6 months, 1 year, 2 years

  4. To determine whether NextAR system data contributes to change patient outcomes using the Forgotten Joint Score using the International Knee Documentation Committee

    To determine whether NextAR system data contributes to change patient outcomes using the Forgotten Joint Score using the International Knee Documentation Committee International Knee Documentation Committee is questionnaire that evaluates physical activity, level of pain and knee functionality in sporting activities. This score goes from a minimum of 0 to a maximum of 100 points.

    Time frame: pre-op, 6 weeks, 6 months, 1 year, 2 years

06

Study locations

1 of 1 sites recruiting
  • Fremantle Hospital
    Fremantle, Australia
    • Ben Jeffcote · Contact
    Recruiting
07

References and documents

Individual participant data

Plan to share: No

No publications or documents are linked to this record.

08

Registry details

Key details

Study ID
NCT05863741
Lead sponsor
Medacta International SA
Responsible party
Sponsor
First posted
May 18, 2023
Start date
May 15, 2022
Primary completion
May 12, 2025
Completion
May 2026 (estimated)
Last update
Sep 29, 2025

Study contacts

Arianna Girardi
Contact
girardi@medacta.ch
+41 91 696 60 60
Ben Jeffcote
principal investigator · Fremantle Hospital

Oversight

Data monitoring committee
No
FDA-regulated drug
No
FDA-regulated device
No
View the source record on ClinicalTrials.gov ↗

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