An observational study in Inflammatory Arthritis, Primary Total Knee Arthroplasty Due to Degenerative Joint Disease (Primary Diagnosis of Osteoarthritis) and Post-traumatic Arthritis, sponsored by Smith & Nephew, Inc.. Recruiting at 4 sites in United States. Open to participants aged 18 Years to 80 Years. Per ClinicalTrials.gov, last updated 2026-08-06.
Sponsored by Smith & Nephew, Inc. · Observational
The purpose of this study is to assess the long-term safety and performance of the LEGION Medial Stabilized insert and to generate clinical evidence to support and maintain product registration in global markets.
This is a post market, prospective and retro-prospective, multicentered 10-year observational study. The study is looking at the LEGION Medial Stabilized insert used in primary total knee arthroplasty alongside specific tibia and femur component combinations. There will be 144 knees enrolled across 3 cohorts in the study. All enrolled knees will undergo a primary knee arthroplasty due to degenerative joint disease (primary diagnosis of osteoarthritis), post-traumatic arthritis or inflammatory arthritis. Enrolled subjects will be followed up for 10 years post operation.
Participants needing primary Total Knee Arthroplasty (TKA) due to degenerative joint disease (primary diagnosis of osteoarthritis), post-traumatic arthritis or inflammatory arthritis.
OR
Participants which have 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:
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:
Exclusion Criteria:
LEGION MS with Cemented Tibia (JII) with LEGION CR non-porous (CoCr) Femoral component
Device: Cemented CoCr
LEGION MS with Cemented Tibia (JII) with LEGION CR non-porous (Ox) Femoral component
Device: Cemented Oxinium
LEGION MS with CONCELOC Tibia with LEGION CR porous (without HA) Femoral component
Device: Cementless
Primary TKA performed using the LEGION MS with Cemented Tibia (JII) with LEGION CR non-porous (CoCr) Femoral component
Primary TKA performed using the LEGION MS with Cemented Tibia (JII) with LEGION CR non-porous (Ox) Femoral component
Primary TKA performed using the LEGION MS with CONCELOC Tibia with LEGION CR porous (without HA) Femoral component
Implant Survivorship at 10 Years
Implant survivorship at 10 years post-surgery. Implant survivorship is defined as the cumulative proportion of knee-implanted components without a revision. Survivorship is defined as absence of revision of any, or all, of the tibial / femoral / insert components that were implanted during the primary TKA - not including the patella. (Revision is the removal of some, or all, of the above specified implant components, and replacement with new ones for any reason).
Time frame: 10 years
Implant Survivorship
Implant survivorship at 6 weeks, 1, 2, 3, 5, 7 years post-surgery. Implant survivorship is defined as the cumulative proportion of knee-implanted components without a revision. Survivorship is defined as absence of revision of any, or all, of the tibial / femoral / insert components that were implanted during the primary TKA - not including the patella. (Revision is the removal of some, or all, of the above specified implant components, and replacement with new ones for any reason).
Time frame: 6 weeks, 1 year, 2 years, 3 years, 5 years, and 7 years
Knee Injury and Osteoarthritis Outcome Score for Joint Replacement (KOOS JR)
The Knee injury and Osteoarthritis Outcome Score for Joint Replacement (KOOS, JR) is a validated short form of the KOOS that assesses patient stiffness (1 item), pain (4 items), and functions of daily living (2 items). Scores range from 0 to 100 with a score of 0 indicating total knee disability (i.e., worse outcome) and 100 indicating perfect knee health (i.e., better outcome).
Time frame: 6 weeks, 1 year, 2 years, 3 years, 5 years, 7 years, and 10 years
Oxford Knee Score (OKS)
The OKS consists of twelve questions covering function and pain associated with the knee. Scores from the twelve questions are combined to provide an overall score that ranges from 0 to 48, with higher scores indicating better knee function and less pain (i.e., a better outcome)
Time frame: 6 weeks, 1 year, 2 years, 3 years, 5 years, 7 years, and 10 years
Forgotten Joint Score (FJS)
The Forgotten Joint Score (FJS) is a patient reported outcome that focuses on the participant's awareness of a specific joint in everyday life. Joint awareness can be simply defined as any unintended perception of a joint. Scores are on a scale of 1 to 100, with higher scores indicating a better outcome.
Time frame: 6 weeks, 1 year, 2 years, 3 years, 5 years, 7 years, and 10 years
Five-Level EuroQol Five-Dimensional (EQ-5D-5L): Index Score
The EQ-5D-5L score consists of two parts: a descriptive system and a visual analogue scale (VAS). The descriptive system (i.e., index score) is used to describe the participant's health state and consists of five dimensions: mobility, self-care, usual activities, pain/discomfort and anxiety/depression. Each dimension has 5 levels to choose the most appropriate answer: no problems, slight problems, moderate problems, severe problems and extreme problems. The participant is asked to indicate their health state by marking the most appropriate statement in each of the five areas. The EQ-5D-5L Index Score was based on a scale of 0 to 1, with higher index values indicating better health and lower index values indicating worse health.
Time frame: 6 weeks, 1 year, 2 years, 3 years, 5 years, 7 years, and 10 years
Five-Level EuroQol Five-Dimensional (EQ-5D-5L): Visual Analogue Scale Score
The EQ-5D-5L score consists of two parts: a descriptive system and a visual analogue scale (VAS). The VAS records the participant's self-rated health on a vertical visual analogue scale. The scale ranges from 0 to 100 where 0 indicates 'The worst health you can imagine' and 100 indicates 'The best health you can imagine'.
Time frame: 6 weeks, 1 year, 2 years, 3 years, 5 years, 7 years, and 10 years
Plan to share: No
No publications or documents are linked to this record.
Eligibility is decided by the study team. Share this record with your doctor or contact the team directly.
Contact study teamGet an email when the registry record changes — status, dates, results — or when someone posts here.
Sign in to followQuestions and observations about this study, from anyone following it. Not medical advice, and not a channel to the study team — their contact details are on the registry record.
Sign in to join the discussion. Reading takes no account; posting does. You choose a display name, and a pseudonym is the default.
Nothing here yet. If you are running this trial, taking part in it, or weighing whether to, this is the place to say so.
Smith & Nephew, Inc.