Triathlon Total Stabilizer (TS) Outcomes Study

Study Overview
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Brief Summary
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This study will be a prospective, non-randomized evaluation of the change between preoperative and postoperative outcomes for those receiving the Triathlon® TS Total Knee System for a revision knee operation. The mean total Knee Society Score (for pain, motion and function) change is not 10% worse than, or is superior to, the expected change according to published revision total knee replacement data, for cases implanted with the Triathlon® TS Total Knee System as compared from preoperative to 2 years postoperative.

Official Title
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A Prospective, Post-market, Multi-center Study of the Outcomes of the Triathlon® Total Stabilizer (TS) Total Knee System

Conditions
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Arthroplasty, Replacement, Knee

Intervention / Treatment
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* Device: Triathlon TS Knee System


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Patient has signed an Institutional Review Board (IRB) approved, study specific Informed Patient Consent Form. Patient is a male or non-pregnant female age 18 years or older at time of study device implantation. Patient is a candidate for revision of all femoral and tibial components of a total knee replacement. Patient is willing and able to comply with postoperative scheduled clinical and radiographic evaluations and rehabilitation. Exclusion Criteria: Patient has a Body Mass Index (BMI) > 40. Patient has an active or suspected latent infection in or about the affected knee joint at time of study device implantation. Patient has a neuromuscular or neurosensory deficiency, which limits the ability to evaluate the safety and efficacy of the device. Patient is diagnosed with a systemic disease (e.g. Lupus Erythematosus) or a metabolic disorder (e.g. Paget's Disease) leading to progressive bone deterioration. Patient is immunologically suppressed or receiving steroids in excess of normal physiological requirements (e.g. > 30 days). Patient has a failed unicondylar knee prosthesis. Patient has a known sensitivity to device materials. Patient is a prisoner.

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Intervention Model: Single Group Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Other: Triathlon TS Knee<br>Triathlon TS Knee System | Device: Triathlon TS Knee System<br>* Total knee replacement for revision cases<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Knee Society Score (KSS) Change From Preoperative Time Point to 2 Years | KSS Pain score, KSS Function score, Total Combined KSS The Knee Society Clinical Rating System is comprised of two distinct sub-scores: one for pain, range of motion (ROM) and joint stability, and one for functional parameters. Sub-scores range from a potential minimum score of 0 to a maximum score of 100 points. Although the specific scores are not distinguished as excellent, good, fair, or poor, a higher value represents a better outcome. Additionally, the KSS Pain subscore and KSS Function subscore are added together to obtain a total combined score (minimum score 0, maximum score 200). | pre-op, 2 years | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Knee Society Score (KSS) Functional Results Stratified by Joint Line Restoration Groups at 2 and 5 Years Postoperative | This outcome measure shows the results of the KSS Functional Score for the groupings of the Joint Line Restoration (JLR). The 2 groups of JLR were stratified by the amount in mm that the joint line was restored to the physiological joint line postoperative. One group was those that were restored to ≤ 5 mm and the other was those that were restored to > 5mm. The Functional Score of the Knee Society Clinical Rating System ranges from a potential minimum score of 0 to a maximum score of 100 points. It is based on points assigned to ability to walk, climb stairs and the use of ambulatory aids. A higher value represents a better outcome. | 2 years, 5 years | 
| Knee Stability Results Stratified by Joint Line Restoration Groups at 2 and 5 Year Postoperative | Measures the knee stability results for the groupings of the Joint Line Restoration (JLR). The 2 groups of JLR were stratified by amount in mm that the joint line was restored to physiological joint line postoperative. One group were restored to ≤ 5 mm and the other were restored to > 5mm. Knee stability is evaluated in the anterior-posterior (AP) and medial-lateral (ML) planes. AP drawer test determines instability in mm of the tibia. It was done in the AP plane in both JLR groupings (≤ 5mm and > 5mm) at 2 years and 5 years. The AP measurements were sub categorized into 5mm and 5-10mm. ML is tested with a varus valgus stress test to determine any instability as measured in degrees. The ML measurements were done in both JLR groupings (≤ 5mm and > 5mm) at 2 years and 5 years with all results in only one category of < 5 degrees. The higher the number of degrees or mm measured the more instability in the knee. | 2 year and 5 year postoperative | 
| Anterior Knee Pain Results Stratified by Joint Line Restoration Groups at 2 and 5 Years Postoperative | Measures the presence or absence of anterior knee pain in the groupings of the Joint Line Restoration (JLR). The 2 groups of JLR were stratified by the amount in mm that the joint line was restored to the physiological joint line postoperative. One group was those that were restored to ≤ 5 mm and the other was those that were restored to > 5mm. Anterior knee pain is determined by clinical examination with patient and clinician whether it is present or absent. | 2 year and 5 year postoperative | 
| Short Form Health Survey (SF-36) Health Survey Change From Pre-op to Post-op Visits | The SF-36 Health Survey is a 36-item patient completed questionnaire to measure general health and well-being. It includes a physical and mental status component score; each ranging from 0-100. Low values represent a poor health state and high values represent a good health state. | pre-op, 1, 2, 5 years | 
| Number of Knees With Radiographic Stability at 1, 2 and 5 Years Postoperative | The scoring system was based on the Knee Society guidelines and determined by measuring the width of the radiolucent lines for each of the zones of the implant components in millimeters. The total widths are added for each zone which produces a numerical score. Radiolucency in at least 50% of a zone and measuring at least 1 mm in width is defined as radiolucency present. Failure is defined as a score of 10 or greater, regardless of symptoms and considered as radiographic instability. | 1, 2, 5 years | 
| Number of Knees With a Revision of Femoral and/or Tibial Baseplate Component | Revision was defined as the removal of either the femoral component or the tibial baseplate component. | 5 years | 
| Knee Injury and Osteoarthritis Outcome Score (KOOS) Change From Pre-op to Post-op Visits | KOOS consists of 5 subscales; Pain, other Symptoms, Function in daily living (ADL), Function in sport and recreation (Sport/Rec) and knee related Quality of life (QOL). The last week is taken into consideration when answering the questions. Standardized answer options are given (5 Likert boxes) and each question gets a score from 0 to 4. A normalized score (100 indicating no symptoms and 0 indicating extreme symptoms) is calculated for each subscale. | pre-op, 1, 2, 5 years | 
| Hospital Special Surgery (HSS) Patella Score Change From Pre-op to Post-op Visits | The HSS Patella Score incorporates both subjective symptoms and objective data specific to the patellofemoral joint. It consists of one score from 0-100 with a score of 100 indicating no pain, no functional limitations, no tenderness or crepitus and normal quadriceps strength. | pre-op, 1, 2, 5 years | 
| Lower Extremity Activity Scale (LEAS) Score Change From Pre-op to Post-op Visits | The LEAS is completed by the participant to assess activity level. Activity levels were ordered in terms of intensity from 1 to 18, with 18 indicating the highest activity level. | pre-op, 1, 2, 5 years | 
| Knee Society Score (KSS) Change From Pre-op to Post-op Visits | The Knee Society Clinical Rating System is comprised of two distinct sub-scores: one for pain, ROM and joint stability, and one for functional parameters. Sub-scores range from a potential minimum score of 0 to a maximum score of 100 points. Although the specific scores are not distinguished as excellent, good, fair, or poor, a higher value represents a better outcome. | pre-op, 1,2, 5 year |