Medacta NextAR TKA Pivotal Trial

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).

Study Overview

• Status: Completed
• Conditions: Musculoskeletal Diseases
• Intervention / Treatment: Device: NextAR TKA system

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 Type: Interventional
• Enrollment (Actual): 40
• Phase: Not Applicable

Contacts and Locations

Study Locations

• Switzerland
  • Schaffhausen, Switzerland, 8200
    • Privatklinik Belair
  • Winterthur, Switzerland, 8401
    • Kantonsspital Winterthur
  • Winterthur, Switzerland, 8400
    • Privatklinik Lindberg
  • Zurich, Switzerland, 8008
    • Uniklinik Balgrist

Participation Criteria

Eligibility Criteria

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

Description

Inclusion Criteria:

1. Males and females aged over 18 years at time of surgery.
2. Patients who are scheduled to receive Medacta GMK® Sphere system for primary TKA (class III, CE-marked).
3. Patients with functional contralateral knee (i.e. without the need to use walking aids).
4. Patients willing and able to provide written informed consent for participation.
5. Patients willing to comply with the pre and post-operative evaluation schedule.

Exclusion Criteria:

1. 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
2. Patients whose prospects for a recovery to independent mobility would be compromised by known coexistent, medical problems.
3. Patients affected by concomitant spine, hip, ankle or contralateral knee pathologies that can affect walking capacity.
4. Patients unable to understand and take action.
5. Patients with known allergy to the materials used.
6. Patients in which Medacta GMK® Sphere system is used in emergency interventions.

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
Experimental: Single-arm; 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.	Device: NextAR TKA system; The NextAR TKA system is a surgical guidance system which measures intra-operatively the effect of prosthesis alignment and positioning on soft tissue balance.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Oxford Knee Score (OKS)	Oxford Knee Score (OKS) [Range: 0-48; higher values indicate better outcomes]	6 months

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Oxford Knee Score (OKS)	Oxford Knee Score (OKS) [Range: 0-48; higher values indicate better outcomes]	12 months
Forgotten Joint Score (FJS)	Forgotten Joint Score (FJS) [Range: 0-100; higher values indicate better outcomes]	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]	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	2 months and 12 months
Surgical Outcome - Surgical Time	Surgical time (min)	Intraoperative
Surgical Outcome - Necessity of Soft Tissue Release	Necessity of soft tissue release to obtain ligament or patellar balance (Y/N)	Intraoperative
Surgical Outcome -Time to Discharge	Time to discharge (days)	2 months
Safety Outcomes	Device deficiencies and adverse events	Intraoperative, 2 months, 6 months and 12 months

Collaborators and Investigators

• Sponsor: Medacta International SA
• Investigators: Principal Investigator: Sandro Fucentese, Prof. Dr. med., Balgrist University Hospital

Study record dates

Study Major Dates

• Study Start (Actual): May 17, 2021
• Primary Completion (Actual): December 31, 2023
• Study Completion (Actual): June 18, 2024

Study Registration Dates

• First Submitted: April 8, 2021
• First Submitted That Met QC Criteria: April 12, 2021
• First Posted (Actual): April 14, 2021

Study Record Updates

• Last Update Posted (Actual): March 2, 2026
• Last Update Submitted That Met QC Criteria: February 17, 2026
• Last Verified: February 1, 2026

More Information

Terms related to this study

• Keywords: total knee arthroplasty; surgical navigation; medially-stabilized TKA
• Additional Relevant MeSH Terms: Musculoskeletal Diseases
• Other Study ID Numbers: P02.022.02

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No
• product manufactured in and exported from the U.S.: No