Kinematic Comparison of Vanguard XP and Vanguard CR Total Knee Arthroplasties

Study Overview
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Brief Summary
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Primary: The primary objective of this pilot study is to compare the intraarticular kinematics by fluoroscopy of Vanguard XP to that of Vanguard CR. Secondary: The secondary objective of this pilot study is to compare the standing balance by force plate of patients with the Vanguard XP prosthesis to those who have Vanguard CR prosthesis. Furthermore, we wish to assess isometric quadriceps muscle strength in both groups.

Official Title
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Comparison of Vanguard XP and Vanguard CR Total Knee Arthroplasties: A Cross Sectional Pilot Study Evaluating Intraarticular Kinematics and Standing Balance by Dynamic Fluoroscopy and Force Plate Examination

Conditions
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Osteoarthritis

Intervention / Treatment
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* Device: Total knee arthroplasty with Vanguard XP
* Device: Total knee arthroplasty with Vanguard CR


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Participant in the XP vs. CR study (inherited traits from study inclusion) Overall healthy. Have attended standard physiotherapy after unilateral total knee replacement Are able to perform the tasks Excellent clinical scores (Oxford Knee Score above 39 at 1 year follow up) Exclusion Criteria: Knee pain above 20 on a 0-100 visual analogue scale Any clinical relevant pain from adjacent joints Active Knee flexion below 100 Signs of implant migration, loosening, and implant mal-alignment

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 75 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
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Single


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: Total knee arthroplasty with Vanguard XP<br>The new Vanguard XP Total knee arthroplasty system is a further development of the Vanguard TKA. The new Vanguard XP system both cruciate ligaments are preserved. | Device: Total knee arthroplasty with Vanguard XP<br> <br> Device: Total knee arthroplasty with Vanguard CR<br> <br> |
| Active Comparator: Total knee arthroplasty with Vanguard CR<br>Total knee arthroplasty system without preservation of the anterior cruciate ligament | Device: Total knee arthroplasty with Vanguard XP<br> <br> Device: Total knee arthroplasty with Vanguard CR<br> <br> |

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Anterior-posterior translation of the femoral component with respect to the tibia component | Group mean in millimeters (mm) | at least one year post surgery | 
| Axial rotation of the femoral component with respect to the tibia component | Group mean in degrees (°) | at least one year post surgery | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Traveled distance of center of pressure | Group mean in centimeters (cm) | at least one year post surgery | 
| Velocity of center of pressure | Group mean in mm/second | at least one year post surgery | 
| Rambling-trembling distance | Group mean in mm | at least one year post surgery | 
| Isometric quadriceps muscle strength | Group mean in newton meter pr. kilograms weight (Nm/kg) | at least one year post surgery |