A Single Time-Point Study to Evaluate the ConforMIS iTotal® (CR) Knee Versus Off-the-Shelf

Study Overview
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Brief Summary
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It has been noted that patients dramatically overestimate their functional ability early after surgery. Despite use of assistive devices increasing and functional testing scores decreasing post-surgery, the patient reported outcome scores fail to show worsening. Outcome questionnaires will be administered and functional testing will be conducted on all patients to capture these changes.

Detailed Description
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The functional testing used in this study consists of tests that physical therapists use daily as objective methods to assess patients' functional status. The testing is designed to closely mimic daily activities that the patients are familiar with.

Official Title
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A Single Time-Point Study to Evaluate the ConforMIS iTotal® (CR) Knee Replacement System Versus Off-the-Shelf Replacement

Conditions
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Osteoarthritis

Intervention / Treatment
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* Device: ConforMIS Total Knee Replacement System
* Device: Off-the-Shelf Knee Replacement System


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Implant must be at least 6 months post-op and doing well Patient has had a total CR knee implant > 18 years of age Exclusion Criteria: Simultaneous bilateral procedure occurred BMI > 40 Other physical disability that requires an aid for walking or disability affecting the hips, spine, contralateral knee or other joint that limits function Participation in another clinical study which would confound results Inability to complete the protocol in the opinion of the clinical staff due to safety or other reasons

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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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| ConforMIS iTotal Knee Replacement System<br>Patients who have had an iTotal knee replacement at least 6 months prior to testing | Device: ConforMIS Total Knee Replacement System<br>* Total knee replacement system using a patient specific implant.<br>|
| Off-the-Shelf Knee Replacement System<br>Patients who have had an off-the-shelf knee replacement at least 6 months prior to testing | Device: Off-the-Shelf Knee Replacement System<br>* Total knee replacement system not using a patient specific implant.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Functional Outcome time differences between the two groups | The study primary endpoint is to compare functional testing time between patients implanted with the iTotal implant verses the off-the-shelf implants | at least 6 months post-op | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Outcomes questionnaire- Knee Society Score | Comparing different patient outcome scores between the two groups | At least 6 months post op | 
| Outcomes questionnaire- KOOS | Comparing different patient outcome scores between the two groups | At least 6 months post op | 
| Outcomes questionnaire- Forgotten Joint Score | Comparing different patient outcome scores between the two groups | At least 6 months post op |