The Medacta International GMK Sphere Cementless Post-Marketing Surveillance Study

A Prospective, Multicentre, International, Post-marketing, Longitudinal, Observational Cohort Study to Monitor the Performances of GMK Sphere Cementless Knee Prosthesis

This is a Post-Marketing Surveillance study of GMK Sphere cementless knee prosthesis.

Study Overview

• Status: Active, not recruiting
• Conditions: Arthritis; Rheumatoid Arthritis; Avascular Necrosis; Traumatic Arthritis; Poly-arthritis
• Intervention / Treatment: Device: GMK Sphere cementless Knee Replacement

• Study Type: Observational
• Enrollment (Estimated): 200

Contacts and Locations

Study Locations

• France
  • Bourgoin, France, 38300
    • Clinique Saint Vincent de Paul
  • Caen, France, 14000
    • Clinique du Parc
  • Colmar, France, 68000
    • Hôpitaux Civils de Colmar
  • Cucq, France, 62780
    • Clinique des Acacias
• Switzerland
  • Meyrin, Switzerland, CH-1217
    • Hôpital de la Tour

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years to 80 years (Adult, Older Adult)
• Accepts Healthy Volunteers: No

• Sampling Method: Non-Probability Sample

Study Population

Patients requiring Total Knee Arthroplasty and who are suitable to receive Medacta GMK Sphere cementless Knee Replacement will be proposed to take part to the current post-market surveillance study during their pre-operative visit.

Description

Inclusion Criteria:

• A disabled or severely disabled joint as a result of arthritis, traumatic arthritis, rheumatoid arthritis, poly-arthritis or avascular necrosis
• Patients between the age of 18 and 80 at the time of consent
• Listed for total knee replacement surgery.
• Patients who are willing and able to give informed written consent

Exclusion Criteria:

• Progressive local or systemic infection
• Muscular loss, neuromuscular disease or vascular deficiency of the affected limb, making the operation unjustifiable
• Severe instability secondary to advance destruction of condralar structures or loss of integrity of the medial or lateral ligament
• Those whose prospects for a recovery to independent mobility would be compromised by known coexistent, medical problems
• Patient whose BMI exceeds 40
• Any case not described in the inclusion criteria

Study Plan

How is the study designed?

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Survival rate	Kaplan Meier method	10 years

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Clinical outcome: Knee Society score	Knee Society Score (KSS): evaluates pain, in a total of 50 points, stability, 25 points, and range of motion, 25 points. The maximum score of 100 points is reached when there is no pain, with good alignment of the knee in extension, and at least 125° of range of motion, without any anteroposterior or mediolateral instability.	Preop and 1, 2, 5, 10 years postop
Patient-reported outcome: Forgotten Joint Score	Forgotten Joint Score (FJS) is a patient-reported outcome measure intended to determine a patient's ability to "forget" about their affected joint after surgery or treatment.It consists of 12 questions and is scored on a 0-100 scale. The higher the score, the less the patient is aware of their affected joint when performing daily activities	1, 2, 5, 10 years postop
Radiographic performance of the implants looking for radiolucencies, migration, loosening, subsidence	Presence of radiolucencies, migration, loosening, subsidence	Immediately postop + 1, 2, 5, 10 years postop
Intraoperative and postoperative Adverse events	Intraoperative and postoperative adverse events	Intraop + Immediately postop + 1, 2, 5, 10 years postop

Collaborators and Investigators

• Sponsor: Medacta International SA
• Investigators: Principal Investigator: Emmanuel Marchetti, MD, Clinique Saint Vincent de Paul

Study record dates

Study Major Dates

• Study Start (Actual): January 14, 2020
• Primary Completion (Estimated): January 31, 2030
• Study Completion (Estimated): December 31, 2032

Study Registration Dates

• First Submitted: August 6, 2021
• First Submitted That Met QC Criteria: August 6, 2021
• First Posted (Actual): August 12, 2021

Study Record Updates

• Last Update Posted (Estimated): September 29, 2025
• Last Update Submitted That Met QC Criteria: September 23, 2025
• Last Verified: June 1, 2025

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Bone Diseases; Musculoskeletal Diseases; Pathologic Processes; Joint Diseases; Rheumatic Diseases; Connective Tissue Diseases; Autoimmune Diseases; Immune System Diseases; Necrosis; Pathological Conditions, Signs and Symptoms; Skin and Connective Tissue Diseases; Arthritis; Arthritis, Rheumatoid; Osteonecrosis
• Other Study ID Numbers: P02.014.26

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