Evaluation of the 5C® MEDic Knee System (5C Knee)

Evaluation of the Midterm Results of the 5C® MEDic Knee System

This prospective study wants to demonstrate the safety and clinical performance of the 5C® MEDic Knee System following total knee arthroplasty. Additionally, all observed product-related complications are documented during the course of the follow-up study. These observations help to re-assess current (known) risks and identify new ones. The data obtained during this study is part of the post market surveillance.

Study Overview

• Status: Not yet recruiting
• Conditions: Knee Degenerative Disease
• Intervention / Treatment: Device: 5C® Knee System prothesis

Detailed Description

Despite significant advancements in total knee replacement surgery, patient-reported satisfaction rates remain around 80-90%. The native knee joint kinematics are driven by the asymmetric articular surfaces where the medial tibial plateau is concave while the lateral is convex. The C-shaped medial meniscus has anterior and posterior lips that resist translation while the lateral meniscus has a circular shape allowing for 15° of anterior to posterior motion and an 11 mm of translation. As the knee flexes, the medial femoral condyle has a static centre of rotation without anteroposterior translation while the lateral femoral condyle translates posteriorly resulting in relative internal rotation of the tibia around a medial pivot.

The design of medial pivot knee prosthesis closely replicates these native knee kinematics. The medial ball in-socket design offers a highly conforming implant resulting in low contact stress and minimal edge loading.

On the other hand, the lateral arcuate trough provides less conformity therefore facilitating posterior translation of the lateral contact point during flexion recreating the native posterior femoral rollback. Over recent years, the medial pivot knee arthroplasty has gained popularity with multiple studies reporting enhanced patients' reported outcomes compared to other designs. Despite the favourable outcomes reported in the literature, there is still lack of sufficient data in the literature regarding the reported patient's outcomes and the overall revision rate of these medial pivot designs.

This prospective study wants to demonstrate the safety and clinical performance of the 5C® MEDic Knee System following total knee arthroplasty. Additionally, all observed product-related complications are documented during the course of the follow-up study. These observations help to re-assess current (known) risks and identify new ones. The data obtained during this study is part of the post market surveillance.

• Study Type: Interventional
• Enrollment (Estimated): 100
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Anna Tarasiuk; Phone Number: +32 16 33 88 18; Email: orthopedie.research@uzleuven.be
• Study Contact Backup: Name: Hazem Wafa, Dr.; Phone Number: +32 16 33 88 73; Email: hazem.wafa@uzleuven.be

Study Locations

• Belgium
  • Vlaams-Brabant
    • Leuven, Vlaams-Brabant, Belgium, 3000
      • Universitaire Ziekenhuizen KU Leuven
      • Contact: Anna Tarasiuk; Phone Number: +32 16 33 88 18; Email: orthopedie.research@uzleuven.be
      • Contact: Hazem Wafa, Dr.; Phone Number: +32 16 33 88 73; Email: hazem.wafa@uzleuven.be
      • Principal Investigator: Hazem Wafa

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

1. Voluntary written informed consent of the participant has been obtained prior to any screening procedures
2. At least 18 years of age at the time of signing the Informed Consent Form (ICF)
3. The patient will be operated at the Leuven University Hospital (primary or revision surgery).
4. The patient will receive the 5C® MEDic Knee System (manufactured by implantcast GmbH).

5. The implantation will be performed according to the medical indications listed in the product specific Instruction for Use (IFU):

   1. Non-inflammatory degenerative joint disease including osteoarthritis and avascular necrosis,
   2. Post-traumatic osteoarthritis
   3. Treatment of fractures that are unmanageable using other surgical techniques
   4. Rheumatoid arthritis
   5. Revision arthroplasty (revision prosthesis)
6. The patient is willing and able to follow all study specific procedures and to attend the follow-up visits at the study site
7. The patient agrees to be contacted by telephone or by mail.

Exclusion Criteria:

1. The patient is <18 years of age, or unable to understand and sign a written informed consent form or legally incompetent or limited in his legal capacity.
2. Patient has history of malignancy within the past 5 years before screening.
3. Patients with Adipositas permagna (BMI ≥40 kg/m²).
4. Has a current infection as well as infections close (in the opinion of the investigator) to the knee joint within the last 3 years.
5. Known allergy to any of the implant materials.
6. Female who is pregnant or intends to become pregnant during screening and at the moment of operation
7. Not a suitable candidate for enrollment or unlikely to comply with the requirements of this study, as assessed by the Investigator.
8. Current alcohol and/or drug abuse or other addictions that might impair the patient's capacity to estimate the nature and the scope of the study.
9. Bilateral Total Knee Arthroplasty in a period of < 3 months.
10. Physiological or anatomical conditions, which preclude or are not expected to maintain adequate bony support of the implant or do not allow the implantation of a sufficiently large prosthesis, in the opinion of the investigator.
11. Bone tumors in the implant fixation area.
12. Has an untreated vascular diseases which limit blood supply to the affected limb, in the opinion of the investigator
13. Has a metabolic disorders that may impair bone formation.
14. In case of insufficient quantity and quality of bone stock, an alternative prosthetic treatment allowing for sufficient bony fixation should be considered.
15. Has severe axis deviation in treated knee under study and/or non-treated knee.
16. Ligament instability in treated knee under study.
17. Participation in an interventional trial with an investigational medicinal product (IMP) or device within the last four weeks before Screening.
18. Any other clinical history finding that, in the judgment of the investigator, would pose a potential hazard for performing a knee surgery

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Other
• 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: Patients receiving the 5C® MEDic Knee System; Patients who will be operated at the Leuven University Hospital for a total knee arthroplasty and receive the 5C® MEDic Knee System	Device: 5C® Knee System prothesis; During the surgical intervention in this study, the 5C® Knee System prothesis is used.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Revision rate after the 5C® MEDic Knee System	The Implant Survival of the 5C® MEDic Knee System prothesis is determined by the amount of revisions during the follow-up period of 5 years. The question, if a revision is performed after the surgical intervention, can be answered with "yes" or "no". Also, how long the prosthesis remains in place without the need for a second operation (revision) is recorded (in years).	From Surgical intervention to end of study at 5 years post-operative

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
EQ-5D-3L health questionnaire as clinical performance assessment	This questionnaire is used in this study to assess the clinical performance of the 5C® MEDic Knee System during 5 years of follow-up. The questionnaire will evaluate mobility, self-care, usual activities, pain/discomfort and anxiety/depression. Every topic can be answered with "No", "Moderate", "not able to/Extreme". Additionally, patients provide a self-assessment of their overall health using a Visual Analogue Scale (VAS) from 0 to 100, where 0 represents the "worst health imaginable" and 100 represents the "best health imaginable."	From enrollment to the end of the study, following a 5-year follow-up period (pre-operative, post-operative (6 weeks, 6 months, 1 year, 3 years and 5 years))
Forgotten Joint Score questionnaire (FJS-12) as clinical performance assessment	This questionnaire is used in this study to assess the clinical performance of the 5C® MEDic Knee System during 5 years of follow-up. The questionnaire will evaluate "joint/prothesis awareness" during activities of daily living after total knee arthroplasty, meaning to which extent a patient is aware of their prosthetic joint. The questionnaire consists of 12 items, each rated on a 5-point scale (0-4). The total score is transformed to a 0-100 scale, where a higher score indicates a better outcome (i.e., the patient is less aware of the artificial joint).	From enrollment to the end of the study, following a 5-year follow-up period (pre-operative, post-operative (6 weeks, 6 months, 1 year, 3 years and 5 years))
High-Flexion Knee Score questionnaire as clinical performance assessment	This questionnaire is used in this study to assess the clinical performance of the 5C® MEDic Knee System during 5 years of follow-up. The questionnaire will evaluate lifestyle activities that require deep knee flexion. This questionnaire assesses the patient's ability to perform functional tasks such as kneeling, squatting, and sitting cross-legged. The HFKS consists of several items categorized into functional domains, where higher scores represent superior clinical performance and greater ease in performing high-flexion movements.	From enrollment to the end of the study, following a 5-year follow-up period (pre-operative, post-operative (6 weeks, 6 months, 1 year, 3 years and 5 years))
Knee Society Score questionnaire as clinical performance assessment	This questionnaire is used in this study to assess the clinical performance of the 5C® MEDic Knee System during 5 years of follow-up. The Knee Society Score (KSS) is a assessment tool used to evaluate the outcomes of total knee arthroplasty (TKA). It consists of four distinct subscales: Objective Knee Score (completed by the surgeon, measuring alignment and ligament stability); Patient Satisfaction Score (measuring how happy the patient is with the outcome); Patient Expectation Score (measuring if the surgery met preoperative goals); Functional Activity Score (assessing walking, stair climbing, and advanced activities). This approach-combining objective clinical data with patient-reported outcomes-provides a comprehensive overview of the prosthesis's performance and its impact on the patient's quality of life.	From enrollment to the end of the study, following a 5-year follow-up period (pre-operative, post-operative (6 weeks, 6 months, 1 year, 3 years and 5 years))
Radiographic evaluation of the 5C® MEDic Knee System on X-ray images	The radiographic evaluation will be performed according to the "Knee Society Radiographic Evaluation System and Methodology for Total Knee Arthroplasty". The purpose of this scoring system is to accumulate radiographic data in a standardized manner to facilitate more accurate interpretation, documentation and clinical correlation.	From enrollment to a 1-year follow-up period (pre-operative, post-operative (6 weeks, 6 months, 1 year))
Overwiew of complications and incidents during 5 years of follow-up	During surgery and the 5-year follow-up period the number and types of complications and incidents is collected.	From enrollment to the end of the study, following a 5-year follow-up period (pre-operative, post-operative (6 weeks, 6 months, 1 year, 3 years and 5 years))

Collaborators and Investigators

• Sponsor: Universitaire Ziekenhuizen KU Leuven
• Investigators: Principal Investigator: Hazem Wafa, Dr., Universitaire Ziekenhuizen KU Leuven

Study record dates

Study Major Dates

• Study Start (Estimated): April 1, 2026
• Primary Completion (Estimated): April 1, 2035
• Study Completion (Estimated): April 1, 2035

Study Registration Dates

• First Submitted: March 12, 2026
• First Submitted That Met QC Criteria: March 18, 2026
• First Posted (Actual): March 24, 2026

Study Record Updates

• Last Update Posted (Actual): March 24, 2026
• Last Update Submitted That Met QC Criteria: March 18, 2026
• Last Verified: March 1, 2026

More Information

Terms related to this study

• Keywords: 5C® MEDic
• Other Study ID Numbers: S70873

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO
• IPD Plan Description: Individual Participant Data (IPD) will not be shared with third parties to ensure de-identification and maintain strict patient confidentiality in accordance with the General Data Protection Regulation (GDPR). Due to the highly specific nature of complex primary and revision hip arthroplasty-sometimes involving rare congenital pathologies and unique skeletal deformities-sharing raw, granular data poses a significant risk of 'deductive re-identification.' Even without direct identifiers, the combination of rare clinical characteristics and surgical dates could potentially allow for the identification of individual patients. Therefore, only aggregated, pseudonymized data and statistical summaries will be provided for analysis and reporting.

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No