Clinical trial Recruiting at 3 sites Observational Ages 18 to 80

Legion Medial Stabilized insert in total knee replacement

Official title: A Multi-Center Study Assessing the Safety and Efficacy of the LEGION Medial Stabilized (MS) Insert in Patients Undergoing a Total Knee Arthroplasty (TKA)

Run by Smith & Nephew, Inc. · NCT07199738 · Data updated 2026-11-12

This study tests whether the Legion Medial Stabilized insert is safe and works well when used in primary knee replacements for people with osteoarthritis, inflammatory arthritis, or post-traumatic arthritis.

Quick facts

Study typeObservational
Ages18 Years to 80 Years
SexAll
Enrollment144 (estimated)
SponsorSmith & Nephew, Inc.
Industry-sponsored
Locations4 sites (Newton, Massachusetts and 3 other locations)
StatusRecruiting
StartedSeptember 25, 2025
Main results expectedDecember 2036
Study endsDecember 2036
Registry record updatedAugust 6, 2026
Trial IDNCT07199738 on ClinicalTrials.gov

Is this trial a fit for you?

Likely a good fit

Adults undergoing primary TKA for osteoarthritis, post-traumatic arthritis, or inflammatory arthritis, or those who recently had a Legion device implanted for retro-prospective data collection.

Probably not a fit

Patients not receiving benefit may include those for whom the device is not suitable or who experience adverse outcomes unrelated to the device.

A plain-English reading of the study's rules. Only the study team can confirm whether you qualify.

What this trial studies

This is a 10-year, multicenter observational study evaluating the Legion Medial Stabilized insert used with selected tibia and femur components in primary total knee arthroplasty. It includes prospective and retro-prospective data from 144 knees across three cohorts at three sites. Participants will be followed long-term to assess safety and performance and to support global product registration. Interventions involve cemented CoCr, cemented Oxinium, or cementless fixation options. Eligible patients include those undergoing primary TKA for degenerative joint disease, post-traumatic arthritis, or inflammatory arthritis, as well as recent users of the device for retro-prospective analysis, with follow-up planned for 10 years.

Why it matters

Potential benefit: If successful, patients could benefit from validated long-term safety and performance data supporting use of the Legion Medial Stabilized insert in primary knee replacements.

How similar studies have gone: Previous studies of similar knee implant devices have shown favorable safety and performance signals, though this specific insert’s long-term data are being collected in this study.

Who can join: the full rules

Show full inclusion / exclusion criteria
Inclusion Criteria:

1. A). Prospective Subjects: Subject needing primary Total Knee Arthroplasty (TKA) due to degenerative joint disease (primary diagnosis of osteoarthritis), post-traumatic arthritis or inflammatory arthritis.

   OR

   B). Retro-prospective Subjects: Subject has undergone primary TKA using the investigational product in the past 12 months to repair degenerative joint disease, post-traumatic arthritis or inflammatory arthritis and all the following conditions have been met:
   * Pre-operative Knee Injury and Osteoarthritis Outcome Score for Joint Replacement (KOOS JR) has been obtained
   * Post-operative radiographs have been obtained, or these can be collected prospectively in window per schedule of events
   * 12-month post-operative KOOS JR have been obtained, or these can be collected prospectively in window per schedule of events
2. Subject's treating clinician has decided the study device is suitable for the subjects TKA procedure and the study device is used in line with the applicable Instructions For Use (IFU) (listed in section 6).
3. Subject agrees to consent and follow the prospective study visit schedule up to 10 years post-surgery (as defined in the study protocol and informed consent form) by signing the Independent Review Board (IRB)/Independent Ethics Committee (IEC) approved consent form.
4. Subject is able to read, understand and communicate responses to Patient Reported Outcome Measure (PROM).
5. Subject is 18-80 years old at the time of consent (inclusive).

Exclusion Criteria:

1. Subject received revision TKA on the contralateral knee for a previously failed TKA, or Unicondylar Knee Arthroplasty (UKA).
2. Subject has a Body Mass Index (BMI) ≥ 40 at pre-operative visit.
3. Subject has ipsilateral hip arthritis resulting in flexion contracture of the hip joint.
4. At the time of surgery, subject has one or more of the following arthroplasties that are not fully healed and/or well-functioning, in the opinion of the Investigator: Ipsilateral or contralateral primary total hip arthroplasty or hip resurfacing arthroplasty; contralateral primary TKA or UKA.
5. Subject has a condition that may interfere with the TKA survival or outcome (e.g., Paget's or Charcot's disease, vascular insufficiency, lupus, muscular atrophy, uncontrolled diabetes, moderate to severe renal insufficiency or neuromuscular disease).
6. Subject has a known allergy to one or more of the components of the study device.
7. Any subject with hardware present in ipsilateral distal femur or proximal tibia.
8. Any subject that meets the definition of a Vulnerable Subject per ISO 14155 Section 3.55.
9. Subject is entered in another drug, biologic, or device study or has been treated with an investigational product in the past 30 days (30 days from operation/dosing).
10. Subject, in the opinion of the Investigator, has an emotional or neurological condition that would pre-empt their ability or willingness to participate in the study, ability to consent or complete the PROMs, including mental illness, drug or alcohol abuse.
11. In the opinion of the Investigator, or site staff, Subject is at risk for lost to follow-up, or failure to return for scheduled visits.
12. Women who are pregnant, nursing, or of child-bearing potential who are not utilizing highly effective birth control measures at the time of screening or the time of surgery.
13. Subjects who have participated previously in this clinical trial and who have been withdrawn.
14. Subject does not meet the indication or is contraindicated for TKA according to specific Smith+Nephew LEGION Knee System IFU.

Where it's running

  • Newton Wellesley Hospital
    Newton, Massachusetts, United States
    Recruiting
  • New York University Hospital
    New York, New York, United States
    Recruiting
  • Medical University of South Carolina
    Charleston, South Carolina, United States
    Recruiting
  • University of Wisconsin
    Madison, Wisconsin, United States
    Not yet recruiting

Study contacts

Similar studies

Other studies for the same condition or treatment. Recruiting studies are listed first.

How to take part

  1. Review the eligibility criteria above with your treating physician.
  2. Check the official listing on ClinicalTrials.gov for the latest contact details and recruitment status.
  3. Contact the study coordinator or principal investigator to ask for pre-screening. Pre-screening is free and never obligates you to enroll.
Last reviewed 2026-11-14 by the Find a Trial editorial team. Information on this page is for educational purposes and is not medical advice. Always consult qualified healthcare professionals about clinical trial participation.