Musculoskeletal DiseasesNCT04844879
Medacta NextAR TKA Pivotal Trial
A study testing NextAR TKA system in people with Musculoskeletal Diseases, run by Medacta International SA at 4 sites in Switzerland.
Trial summary
The goal of this study is to assess the efficacy and safety of a navigation system providing personalized soft tissue balance data in medially-stabilized total knee arthroplasty (TKA). Read more about this study
- Who is it for?
- Ages 18 years and older
- Conditions the study is for
- Musculoskeletal Diseases
- What is being tested?
- NextAR TKA system
- Type of treatment
- Medical device
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 40 participants
- Where
- 4 sitesSwitzerland
- Study dates
- 17 May 2021to 18 Jun 2024
- Phase
- Interventional
- Are there results?
- Yes, posted in the registrySummary in the doctors' view
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
Who may be able to join
- Males and females aged over 18 years at time of surgery.
- Patients who are scheduled to receive Medacta GMK® Sphere system for primary TKA (class III, CE-marked).
- Patients with functional contralateral knee (i.e. without the need to use walking aids).
- Patients willing and able to provide written informed consent for participation.
- Patients willing to comply with the pre and post-operative evaluation schedule.
Who cannot join
- Patients with one or more medical conditions identified as a contraindication defined by the labelling on any Medacta implants used in this study:
- Patients presenting with progressive local or systemic infection
- Muscular loss, neuromuscular disease or vascular deficiency of the affected limb, making the operation unjustifiable.
- Severe instability secondary to advanced destruction of condralar structures or loss of integrity of the medial or lateral ligament
- Patients whose prospects for a recovery to independent mobility would be compromised by known coexistent, medical problems.
- Patients affected by concomitant spine, hip, ankle or contralateral knee pathologies that can affect walking capacity.
Show all 9Show fewer
- Patients unable to understand and take action.
- Patients with known allergy to the materials used.
- Patients in which Medacta GMK® Sphere system is used in emergency interventions.
Trial locations and contacts
4 sites in 1 country.
Switzerland4 sites
Privatklinik Belair
Schaffhausen, 8200
Privatklinik Lindberg
Winterthur, 8400
Kantonsspital Winterthur
Winterthur, 8401
Uniklinik Balgrist
Zurich, 8008
About this study
Official title: Prospective, Multicentre, Single-arm, Open, Confirmatory Trial to Assess Efficacy and Safety of a Navigation System Providing Personalized Soft Tissue Balance Data in Medially-stabilized Total Knee Arthroplasty
The goal of this study is to assess the efficacy and safety of a navigation system providing personalized soft tissue balance data in medially-stabilized total knee arthroplasty (TKA).
Read the detailed description
This is a prospective, multicentre, single-arm, open, confirmatory clinical investigation to assess the efficacy and safety of a navigation system providing personalized soft tissue balance data in medially-stabilized total knee arthroplasty (TKA).
Participants will be informed about the study, both orally and in writing, during a preoperative visit. The investigator will answer any questions that may arise and will collect the informed consent. During the study, enrolled participants will be able to withdraw at any time and for any reason.
The study is conducted according to the following schedule:
- V1 : Inclusion during a preoperative visit
- V2: Surgery
- V3: Follow-up visit at 2 month post-surgery
- V4: Follow-up visit at 6 months post-surgery
- V5: Follow-up visit at 12 months post-surgery
The following data will be collected:
- Oxford Knee Score (OKS), Knee Society Score (KSS), Forgotten Joint Score (FJS) and patient satisfaction at 6 months and 12 months of follow-up;
- Radiological analysis at 2 and 12 months of follow-up;
- Surgical time (min);
- Necessity of soft tissue release to obtain ligament or patellar balance;
- Time to discharge (days);
- Device deficiencies and peri- and postoperative adverse events.
A web-based data collection tool will be used as Electronic Data Capture (EDC). All the information required by the protocol will be collected in electronic case report forms (eCRF).
The statistical analysis will be performed according to a pre-established statistical analysis plan. Missing values will not be replaced by estimated values but will be considered as missing in the statistical analysis.
- Conditions
- Musculoskeletal Diseases
- Being tested
- NextAR TKA system
- Keywords
- total knee arthroplasty, surgical navigation, medially-stabilized TKA
- Medical subject headings
- Musculoskeletal Diseases
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
NextAR TKA systemDevice
The NextAR TKA system is a surgical guidance system which measures intra-operatively the effect of prosthesis alignment and positioning on soft tissue balance.
| Study group | Role | What they receive |
|---|---|---|
| Single-arm | Experimental | Patients suitable to receive Medacta GMK® Sphere system for primary TKA will be invited to take part to the study during the preoperative visit. Follow-ups are performed after 2, 6 and 12 months. Data collection includes clinical and radiological data for preoperative and postoperative assessments, as well as intraoperative details. Receives: Device: NextAR TKA system |
What is being measured
The primary outcome is the main question the study is designed to answer.
Oxford Knee Score (OKS)
Oxford Knee Score (OKS) [Range: 0-48; higher values indicate better outcomes]
Measured: 6 months
Secondary outcomes (8)
Oxford Knee Score (OKS)
Oxford Knee Score (OKS) [Range: 0-48; higher values indicate better outcomes]
Measured: 12 months
Forgotten Joint Score (FJS)
Forgotten Joint Score (FJS) [Range: 0-100; higher values indicate better outcomes]
Measured: 6 months and 12 months
Objective Knee Society Score (KSS)
Objective Knee Society Score (KSS) [Range: 0-100; higher values indicate better outcomes; total score reported as the average of subscale scores]
Measured: 6 months and 12 months
Radiological Outcomes
X-ray assessment for the evaluation of: implant positioning, presence of radiolucent lines, subsidence, migration of components, presence of heterotopic ossifications or osteolysis
Measured: 2 months and 12 months
Surgical Outcome - Surgical Time
Surgical time (min)
Measured: Intraoperative
Surgical Outcome - Necessity of Soft Tissue Release
Necessity of soft tissue release to obtain ligament or patellar balance (Y/N)
Measured: Intraoperative
Surgical Outcome -Time to Discharge
Time to discharge (days)
Measured: 2 months
Safety Outcomes
Device deficiencies and adverse events
Measured: Intraoperative, 2 months, 6 months and 12 months
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted14 Apr 2021
- Study start17 May 2021
- Primary completion31 Dec 2023
- Study completion18 Jun 2024
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Posted resultsParticipant flow, outcome measures and adverse events reported by the sponsor.
- Other trials for Musculoskeletal DiseasesStudies 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
- 40 participants (actual)
Sponsor and investigators
- Lead sponsor
- Medacta International SA
- Sponsor type
- Industry (pharma, biotech, devices)
- Responsible party
- Sponsor
- Investigators
- Sandro Fucentese, Prof. Dr. med., Principal investigator, Balgrist University Hospital
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT04844879
- Sponsor's protocol ID
- P02.022.02
- Status last verified
- Feb 2026
- First submitted
- 8 Apr 2021
- Last updated
- 2 Mar 2026
- Results posted
- Yes, on ClinicalTrials.gov
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No
Study at a glance
From the registry record, last updated by the sponsor on 2 Mar 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Prospective, Multicentre, Single-arm, Open, Confirmatory Trial to Assess Efficacy and Safety of a Navigation System Providing Personalized Soft Tissue Balance Data in Medially-stabilized Total Knee Arthroplasty
- ClinicalTrials.gov ID
- NCT04844879
- Acronym / sponsor ID
- P02.022.02
- Conditions
- Musculoskeletal Diseases
- Keywords
- total knee arthroplasty, surgical navigation, medially-stabilized TKA
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 40 participants (actual)
- Lead sponsor
- Medacta International SAIndustry (pharma, biotech, devices)
- Study start
- 17 May 2021 (actual)
- Primary completion
- 31 Dec 2023 (actual)
- Study completion
- 18 Jun 2024 (actual)
- First posted
- 14 Apr 2021 (actual)
- Results
- Posted 14 Oct 2025
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
The goal of this study is to assess the efficacy and safety of a navigation system providing personalized soft tissue balance data in medially-stabilized total knee arthroplasty (TKA).
Detailed description
This is a prospective, multicentre, single-arm, open, confirmatory clinical investigation to assess the efficacy and safety of a navigation system providing personalized soft tissue balance data in medially-stabilized total knee arthroplasty (TKA).
Participants will be informed about the study, both orally and in writing, during a preoperative visit. The investigator will answer any questions that may arise and will collect the informed consent. During the study, enrolled participants will be able to withdraw at any time and for any reason.
The study is conducted according to the following schedule:
- V1 : Inclusion during a preoperative visit
- V2: Surgery
- V3: Follow-up visit at 2 month post-surgery
- V4: Follow-up visit at 6 months post-surgery
- V5: Follow-up visit at 12 months post-surgery
The following data will be collected:
- Oxford Knee Score (OKS), Knee Society Score (KSS), Forgotten Joint Score (FJS) and patient satisfaction at 6 months and 12 months of follow-up;
- Radiological analysis at 2 and 12 months of follow-up;
- Surgical time (min);
- Necessity of soft tissue release to obtain ligament or patellar balance;
- Time to discharge (days);
- Device deficiencies and peri- and postoperative adverse events.
A web-based data collection tool will be used as Electronic Data Capture (EDC). All the information required by the protocol will be collected in electronic case report forms (eCRF).
The statistical analysis will be performed according to a pre-established statistical analysis plan. Missing values will not be replaced by estimated values but will be considered as missing in the statistical analysis.
Study design
- Primary purpose
- Treatment
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Number of arms
- 1
| Arm | Type | Receives |
|---|---|---|
| Single-arm | Experimental | Device: NextAR TKA systemPatients suitable to receive Medacta GMK® Sphere system for primary TKA will be invited to take part to the study during the preoperative visit. Follow-ups are performed after 2, 6 and 12 months. Data collection includes clinical and radiological data for preoperative and postoperative assessments, as well as intraoperative details. |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (5 listed)
- Males and females aged over 18 years at time of surgery.
- Patients who are scheduled to receive Medacta GMK® Sphere system for primary TKA (class III, CE-marked).
- Patients with functional contralateral knee (i.e. without the need to use walking aids).
- Patients willing and able to provide written informed consent for participation.
- Patients willing to comply with the pre and post-operative evaluation schedule.
Key exclusion criteria (9 listed)
- Patients with one or more medical conditions identified as a contraindication defined by the labelling on any Medacta implants used in this study:
- Patients whose prospects for a recovery to independent mobility would be compromised by known coexistent, medical problems.
- Patients affected by concomitant spine, hip, ankle or contralateral knee pathologies that can affect walking capacity.
- Patients unable to understand and take action.
- Patients with known allergy to the materials used.
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 |
|---|---|---|
| NextAR TKA systemThe NextAR TKA system is a surgical guidance system which measures intra-operatively the effect of prosthesis alignment and positioning on soft tissue balance. | Device | Single-arm |
Primary outcome
Oxford Knee Score (OKS)
Time frame: 6 months
Oxford Knee Score (OKS) [Range: 0-48; higher values indicate better outcomes]
8 secondary outcomes
Oxford Knee Score (OKS)
Time frame: 12 months
Forgotten Joint Score (FJS)
Time frame: 6 months and 12 months
Objective Knee Society Score (KSS)
Time frame: 6 months and 12 months
Radiological Outcomes
Time frame: 2 months and 12 months
Surgical Outcome - Surgical Time
Time frame: Intraoperative
Surgical Outcome - Necessity of Soft Tissue Release
Time frame: Intraoperative
Surgical Outcome -Time to Discharge
Time frame: 2 months
Safety Outcomes
Time frame: Intraoperative, 2 months, 6 months and 12 months
Results and safety
Loading the posted results from ClinicalTrials.gov…
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 2 Mar 2026.
- Posted resultsParticipant flow, baseline, all outcome measures and adverse events.
- Individual participant dataSharing planned: No
Related trials for Musculoskeletal Diseases
Not yet recruiting
Comparison of High-Intensity and Conventional Physical Therapy in Musculoskeletal Disorders
Low Back Pain, Radicular Syndrome
Enrolling by invitationPhase 2
Extension Study of Infigratinib in Children With Achondroplasia (ACH)
Achondroplasia
RecruitingPhase 3
A Study of MACI in Patients Aged 17 to 65 Years With Symptomatic Chondral or Osteochondral Defects of the Ankle
Chondral Defect, Articular Cartilage Defect
Recruiting
Effect of a Constipation Prevention Checklist in Hip Surgery Patients
Constipation, Perioperative Nursing
RecruitingPhase 2/3
Study to Evaluate the Efficacy and Safety of BMN 333 Versus Vosoritide in Children With Achondroplasia
Achondroplasia
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.
Sandro Fucentese, Prof. Dr. med. principal investigator
Balgrist University Hospital
4 sites in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing NextAR TKA system in people with Musculoskeletal Diseases, run by Medacta International SA at 4 sites in Switzerland.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 5 inclusion and 9 exclusion criteria. 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: finished, as of the sponsor's last update on 2 Mar 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 4 sites in Switzerland. 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?
Yes. Results are posted in the registry (first posted 14 Oct 2025). A summary is in the For doctors view, and the full results are on ClinicalTrials.gov.
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?
Oxford Knee Score (OKS) (time frame: 6 months). 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 2 Mar 2026; AzTrials last refreshed its copy on 30 Oct 2026.