Scorpio Posterior Stabilised (PS) vs Scorpio NRG (Energize) PS - Total Knee Arthroplasty

Study Overview
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Brief Summary
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Single-centre, prospective, randomized comparative study to compare the maximum flexion and Chair Raise achievement ratios of the Scorpio PS and and the Scorpio NRG PS. Documentation of all complications.

Detailed Description
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Surveillance design: Single-centre, prospective, randomized comparative study. Objectives: To compare the maximum flexion (active and passive) and Chair Raise achievement ratios. All complications will be documented. Number of subjects to be enrolled: All consecutive Scorpio patients are included until a group size of 88 is reached. Clinical evaluations: Chair raise test, Stair climb test, Western Ontario McMaster Osteoarthritis Index (WOMAC) patient self evaluation, EuroQuol - 5 dimension (EQ-5D) patient questionnaire. Standard clinical, functional and pain parameters (Knee Society Score), pre-operatively and post-operatively. All per- and post-op complications.

Official Title
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Scorpio PS vs Scorpio NRG PS - Total Knee Arthroplasty Comparative Investigation of Function

Conditions
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Arthroplasty, Replacement, Knee

Intervention / Treatment
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* Device: Scorpio PS (posterior stable)
* Device: Scorpio NRG PS


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Patients requiring a primary total knee arthroplasty (TKA) Male and nonpregnant female patients Between 18 and 80 years of age at time of surgery Patients with a diagnosis of osteoarthritis (OA), avascular necrosis (AVN), and not severe posttraumatic arthritis No previous osteosynthesis of the involved knee during the last 12 months Patients who understand the conditions of the study and are wiling to participate for the length of the described follow up Patients who are capable of, and have given, informed consent for participation in the study Exclusion Criteria: Patients requiring revision surgery of a previous implanted total knee system Patients with a diagnosis of severe posttraumatic arthritis (TA) and rheumatoid arthritis (RA) Patients with active infection Patients with malignancy Patients with an immobile hip or ankle arthrodesis Severe obese patients (BMI > 35) Patients with a neurological deficit Previous history of unicompartmental knee arthroplasty or patellar prosthesis Patients with concurrent illnesses which are likely to affect their outcome

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 80 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: Double


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: Scorpio PS<br>Patients on the waiting list for a total knee prosthesis who fulfil the inclusion and exclusion criteria will be asked to participate in this study and are randomized to receive the Scorpio PS Total Knee Replacement. | Device: Scorpio PS (posterior stable)<br>* Implantation of total knee prosthesis<br>|
| Active Comparator: Scorpio NRG PS<br>Patients on the waiting list for a total knee prosthesis who fulfil the inclusion and exclusion criteria will be asked to participate in this study and are randomized to receive the Scorpio NRG PS Total Knee Replacement. | Device: Scorpio NRG PS<br>* Implantation of total knee prosthesis<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Comparison of Maximum Passive and Active Flexion. | Comparison of maximum flexion, both passive and active between Scorpio NRG PS knee prosthesis and the Scorpio PS knee prosthesis. The active flexion-tolerated range is greater/equal 70 degree. The passive flexion-tolerated range is greater/equal 80 degree. The Hyperextension tolerated range is 0 to 10 degree. Higher scores mean a better outcome. | 5 years follow-up | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Knee Society Score (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. | pre-operative, 6, 12, 26 weeks and 1, 2 and 5 years follow-up | 
| Chair Raise Test | A measurement to assess functional lower extremity strength. The participant is seated on a chair. Arms are crossed at the wrists and held against the chest. The participant is instructed to arise from an adjustable chair with the knees in a 90 degree angle (measurement with Goniometer) without using arms. | pre-operative, 6, 12, 26 weeks and 1, 2 and 5 years follow-up | 
| WOMAC Patient Questionnaire | The WOMAC collects information specific to osteoarthritis outcomes. The patient response questionnaire uses a visual analog scale for pain, measuring factors of general pain, stiffness, and function. Each question is scored from 0 to 4 for each set of factors, with 0 indicating no pain, stiffness, or limited in function, and 4 indicating extreme pain stiffness, or limited in function. Total WOMAC scores range from 0 to 96 wit lower values representing better outcomes. | pre-operative, 12, 26 weeks and 1, 2 and 5 years follow-up | 
| EQ-5D (Euro-Quol 5-Dimension) Patient Questionnaire | The EQ-5D is a subject-completed questionnaire designed to assess subject health state values. The EQ-5D descriptive system comprises the following five dimensions: mobility self care, usual activities, pain/comfort and anxiety/depression. Each dimension has 3 levels indicating no problems, some problems or extreme problems. The index values on a scale between -1 (low) and 1 (high) are showing the average health status according to the 5 dimensions: A low score shows worse health and a high score shows better health. | pre-operative, 12, 26 weeks and 1, 2 and 5 years follow-up |