Comparison of the in Vivo Stability of 2 Cementless TKA Designs

Study Overview
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Brief Summary
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The goal of this randomized controlled trial is to analyze the stability of a cementless Total Knee Arthroplasty (TKA) over time and compare it to a well-documented implant in patients with knee osteoarthritis. The main aim is to answer if there is a difference in stability over time as a measure of long time survivorship in these 2 implants. 50 participants will be randomly allocated to receive either the Triathlon Tritanium (Stryker) or the Global Medacta Knee Sphere (GMK Sphere, Medacta) 3D printed cementless TKAs.

Detailed Description
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Total joint replacement is an efficacious treatment for osteoarthritis of hips and knees. Both TKA and Total Hip Artrhoplasties (THA) have excellent implant survivorship. However, patients' satisfaction is lower in TKA than THA. A possible cause of the discrepancy is the unnatural knee kinematics after TKA. Various implants designs have been developed to solve the problem. The most common fixation mode is cemented TKA with good survival up to 15 years. However, newer series in younger patients also have shown lasting survival with cementless implants (Nilsson KG, Prudhon JL). Among various different designs, the medially stabilized total knee, which are designed to reproduce natural knee kinematics with a medial ball-in-socked design, is a promising implant design (No authors listed). Dynamically the medial pivot knee performs more naturally (Bragonzoni L,Petersen ET) compared to other designs. Most data for this design is available only for the cemented version. Up to now there is no safety study performed that confirms the stability over time for this implant with cementless fixation. In this study, the investigators will therefore analyze the in vivo stability of an uncemented TKA with a medially stabilized design, and compare it with a well-documented comparable implant. In order to do this, the investigators will use the CT based micromotion analysis (Broden C, Broden C). This study will contribute to the understanding of fixation and lead to safety to the patient.

Official Title
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Comparison of the in Vivo Stability of 2 Cementless TKA Designs Using CT Micromotion Analysis - A Randomized Controlled Trial

Conditions
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Knee Osteoarthritis

Intervention / Treatment
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* Procedure: TKA


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: • Patients referred to Kristiansund Hospital for primary total knee replacement surgery for osteoarthritis with Kellgren & Lawrence grade 3 or 4 Exclusion Criteria: Preoperative severe deformity (Hip-Knee-Ankle angle of >5 (valgus) or <-15 degrees (varus) on a full-length leg image at weight bearing Preoperative flexion contracture more than 15° Less than 50 and more than 75 years of age at the time of surgery Use of walking aids because of other musculoskeletal and neuromuscular problems Preoperative diagnosis other than osteoarthritis or avascular necrosis (e.g. rheumatoid arthritis, tumours) Revision arthroplasty Obesity with BMI>35 g/m2 Lateral collateral ligament deficient knee Previous knee joint infection Cognitive dysfunction or severe psychiatric disorders.

Ages Eligible for Study
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Minimum Age: 50 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
Interventional Model Description: Randomized controlled trial
Masking: Single


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Control group<br>Cementless Triathlon Tritanium 3D printed TKA | Procedure: TKA<br>* Total knee artroplasty with medial parapatellar incision and mechanical alignment without navigation<br>|
| Experimental: Study group<br>GMK Sphere cementless 3D printed TKA | Procedure: TKA<br>* Total knee artroplasty with medial parapatellar incision and mechanical alignment without navigation<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| CTMA Maximum Total Translation | The highest total translation on the implant at each time point | Up to 2 years | 
| CTMA Maximum Total Translation | The highest total translation on the implant at each time point | Up to 5 years | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| CTMA Total rotation | Center of mass and peripheral points (degrees) | Up to 2 years | 
| CTMA Total rotation | Center of mass and peripheral points (degrees) | Up to 5 years | 
| CTMA Total translation | Center of mass and peripheral points (millimeters) | Up to 2 years | 
| CTMA Total translation | Center of mass and peripheral points (millimeters) | Up to 5 years | 
| The Forgotten Joint Score (FJS) | Patient Reported Outcome Measure PROMs). 12 item likert scale with scores from 0-4 (0=never, 4= allways). Mean value is multiplied with 25 and the subtracted from 100. Maximum score i 100 (excellent), minimum score is 0 (worse). | Up to 2 years | 
| The Forgotten Joint Score (FJS) | Patient Reported Outcome Measure PROMs). 12 item likert scale with scores from 0-4 (0=never, 4= allways). Mean value is multiplied with 25 and the subtracted from 100. Maximum score i 100 (excellent), minimum score is 0 (worse). | Up to 5 years | 
| The Knee injury and Osteoarthritis Outcome Score (KOOS) | Patient Reported Outcome Measure (PROMs). KOOS consists of 5 subscales; Pain, other Symptoms, Activites of Daily Living (ADL), Sport and Recreation Function (Sport/Rec) and knee-related Quality of Life (QOL). The previous week is the time period considered when answering the questions. Standardized answer options are given (5 Likert boxes) and each question is assigned a score from 0 to 4. A normalized score (100 indicating no symptoms and 0 indicating extreme symptoms) is calculated for each subscale | Up to 2 years | 
| The Knee injury and Osteoarthritis Outcome Score (KOOS) | Patient Reported Outcome Measure (PROMs). KOOS consists of 5 subscales; Pain, other Symptoms, Activites of Daily Living (ADL), Sport and Recreation Function (Sport/Rec) and knee-related Quality of Life (QOL). The previous week is the time period considered when answering the questions. Standardized answer options are given (5 Likert boxes) and each question is assigned a score from 0 to 4. A normalized score (100 indicating no symptoms and 0 indicating extreme symptoms) is calculated for each subscale | Up to 5 years | 
| Range of motion | From full extension to full flexion (degrees) | Up to 2 years | 
| Range of motion | From full extension to full flexion (degrees) | Up to 5 years | 
| HKA | Hip knee ankle angle measured on X-ray (degrees). Deviation from 0 is either varus (-) or valgus (+) | Up to 2 years | 
| HKA | Hip knee ankle angle measured on X-ray (degrees). Deviation from 0 is either varus (-) or valgus (+) | Up to 5 years | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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CT based micromotion analysis, CTMA, Cementless TKA, Uncemented TKA, Total knee replacement, Total knee arthroplasty, TKR, GMK Sphere, Tritanium