Trial Comparing Alignment Techniques - RSA of ATTUNE Knee System

Study Overview
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Brief Summary
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The purpose of this study is to compare migration patterns between mechanical and anatomic alignment surgical techniques for the Attune S+ CR-FB knee system using model-based RSA over the first 2 post-operative years.

Detailed Description
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This is a multi-centre, randomized controlled trial of patients undergoing cruciate-retaining total knee arthroplasty with the Attune S+ fixed bearing TKR system. Patients will be randomized to two study groups: Neutral mechanical alignment; Anatomical alignment. The principal objective of this study is to compare migration patterns between mechanical and anatomic alignment surgical techniques for the Attune S+ CR-FB knee system using model-based RSA over the first 2 post-operative years. Secondary objectives include; comparison of 2-year migration values against published thresholds for adequate short-term fixation, comparison of functional and health status of subjects following surgery, comparison of intra-operative soft-tissue releases, incidence of complications and adverse events, and to assess several health economic parameters relating to the surgery.

Official Title
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Radiostereometric Analysis (RSA) of the ATTUNE Knee System: A Randomized Controlled Trial Comparing Anatomic (Femur First) to Neutral Mechanical Alignment Techniques

Conditions
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Knee Osteoarthritis

Intervention / Treatment
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* Procedure: Neutral Mechanical Alignment
* Procedure: Anatomical Alignment


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Symptomatic osteoarthritis of the knee indicating primary total knee arthroplasty Varus knee deformity of 0 to 10 degrees Sufficient ligamentous function to warrant retention of the posterior cruciate ligament Between the ages of 21 and 80 inclusive Patients willing and able to comply with follow-up requirements and self-evaluations Ability to give informed consent Exclusion Criteria: Active or prior infection Medical condition precluding major surgery Inflammatory arthropathy Prior patellectomy PCL deficiency Major Coronal plane deformity Valgus alignment Bone defects requiring augments, cones and/or stemmed implants Body Mass Index 45 or more

Ages Eligible for Study
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Minimum Age: 21 Years
Maximum Age: 80 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

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
Interventional Model Description: Patients will be randomized to either Neutral mechanical alignment or Anatomical alignment using randomly generated numbers permuted in blocks of 4.
Masking: Single


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: Neutral Mechanical Alignment<br>Total knee arthroplasty: Neutral Mechanical Alignment vs Anatomical Alignment | Procedure: Neutral Mechanical Alignment<br>* Hip-knee-ankle angle of 180° ± 3°.<br>|
| Active Comparator: Anatomical Alignment<br>Total knee arthroplasty: Neutral Mechanical Alignment vs Anatomical Alignment | Procedure: Anatomical Alignment<br>* Restoring a patient's pre-diseased limb alignment<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Implant migration | Measured via radiosteriometric analysis (RSA) | 2 years | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Oxford-12 knee score | The Oxford Knee Score (OKS) is a patient self-administered 12-item questionnaire with each question having a Likaert-like response option. Each item is scored from 0 to 4, and the items are summated, with lower total scores indicating poorer performance. The OKS measures pain and general activities of daily living. | Pre-operative, 6 weeks, 3 months, 6 months, 1 year, 2 years | 
| Pain Catastrophizing Scale (PCS) | The patient are asked to indicate the degree to which they have the above thoughts and feelings when they are experiencing pain. Each PCS item is rated on a 5-point scale: 0 (not at all) to 4 (all the time). The PCS total score is computed by summing responses to the 13 items. PCS total scores range from 0 - 52. | Pre-operative, 12 months | 
| European Quality of Life (EQ-5D-5L) | Evaluate and compare the change from preoperative to 2 years between the study groups timepoints in functional outcomes assessments. The EuroQol 5D 5L questionnaire is a standardized instrument for use as a measure of generic health status - completed by the subject. The EQ5D uses a Likert scale which assesses five states (mobility, self care, usual care, pain and discomfort and anxiety and depression) at five different levels - none(0), slight(1), moderate(2), severe(3) or unable to perform(5). Levels are coded 1-5 and an index score is then generated. | Pre-operative, 6 weeks, 3 months, 6 months, 1 year, 2 years | 
| Pre-operative Patient's Knee Implant Performance (PKIP) | The Pre-surgical and/or Post-surgical Patient's Knee Implant Performance (PKIP) questionnaire is a patient reported questionnaire that consists of 24 questions relating to the patient's awareness of their knee. Questions include the patient's self-confidence about the current status of their knee performance, stability, and overall satisfaction. Each question has a 5, 6 or 10 Likaert- like response option. | Pre-operative, 6 weeks, 3 months, 6 months, 1 year, 2 years | 
| 7. University of California at Los Angeles (UCLA) Activity Level scale | Evaluate and compare the change in UCLA activity score compared to baseline in the study cohort. UCLA activity scores range from 1 to 10, and is a measure of activity with 10 being most active. | Pre-operative, 6 months, 1 year, 2 years | 
| Pain VAS | Evaluate and compare the change from preoperative to 2 years between the study groups timepoints in patient reported satisfaction as measured using the visual analogue scale (VAS) from 0 (No pain) - 100 (Worst pain imaginable) | Preoperative, 6 Weeks, 3 Months, 6 Months, 1 Year, 2 Years | 
| Patient satisfaction: VAS | Evaluate and compare the change from preoperative to 2 years between the study groups timepoints in patient reported pain severity as measured using the visual analogue scale (VAS) from 0 (Unsatisfied) - 100 (Completely satisfied) | Preoperative, 3 Months, 6 Months, 1 Year, 2 Years | 
| Patient complications | Evaluate the type and frequency of the complications/adverse events. | Preoperative, 6 Weeks, 3 Months, 6 Months, 1 Year, 2 Years | 
| Hospital stay | Number of days in hospital | Up to 1 week | 
| Tourniquet time | Length of time tourniquet was applied (minutes) | Intraoperative | 
| Length of surgery | Length of surgery, from open to closing of incision (minutes) | Intraoperative | 
| Blood loss | Amount of blood loss during the procedure (mL) | Intraoperative | 
| Anesthesia type | Anesthesia methods (general, spinal, epidural, TXA) | Intraoperative | 
| Peri-operative pain management | A tabulation of the pain management (Peri-Articular Injection, Femoral Nerve Block, Add. Canal Block or none) used during the procedure. | Intraoperative | 
| Soft tissue release | A tabulation of the tissue released during the procedure (MCL, LCL, PCL, Posterior Capsule Release). | Intraoperative |