Kinematic- Versus Ligament-balanced Mechanical Alignment in TKA

Study Overview
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Brief Summary
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A promising new approach in total knee arthroplasty (TKA) for severe osteoarthritis of the knee joint is the the kinematic aligned procedure (KA). This technique provides prosthesis-positioning based on natural and individual axes of movement. Although first series have shown satisfying results, further verification by prospective studies and final meta-analyses will be required. Thus, the kinematic alignment represents one of the few new developments in TKA. Provided that patients are willing to participate in the study, patients data are collected preoperatively and during routine follow-up examinations and evaluated prospectively. Patients will receive either a conventionally mechanical aligned arthroplasty or a kinematical aligned TKA, according to a randomized procedure. The kinematic alignment will be achieved by the use of custom-made cutting-blocks. Therefore, the patients will undergo a computed tomography of the whole leg on the affected side. This is mandatory in order to provide the individually produced cutting blocks. In order to ensure comparability, patients are stratified regarding their age and gender before inclusion. Outcome will be measured by the use of standard scoring systems regarding function, pain and ROM (range of motion) three, six and 12 months after surgery. This study is a monocentric, prospective, randomized and controlled open study.

Official Title
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A Prospective Randomized Controlled Trial Evaluating Patient Specific Total Knee Arthroplasty Using Kinematic Alignment Versus Ligament-balanced, Mechanical Alignment

Conditions
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Osteo Arthritis Knee

Intervention / Treatment
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* Procedure: Total Knee Arthroplasty


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: - Severe osteoarthritis of the knee joint, intended for total knee arthroplasty Exclusion Criteria: - malalignment with varus of more than 5° or valgus malpositioning, joint instability

Ages Eligible for Study
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Minimum Age: 50 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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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| TKA (mechanical alignment)<br> | Procedure: Total Knee Arthroplasty<br>* The common procedure of Total Knee Arthroplasty is investigated in order to compare the techniques of implantation (kinematic vs mechanical alignment)<br>|
| TKA (kinematic alignment)<br> | Procedure: Total Knee Arthroplasty<br>* The common procedure of Total Knee Arthroplasty is investigated in order to compare the techniques of implantation (kinematic vs mechanical alignment)<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change of Range of Motion (ROM) after kinematic vs mechanical aligned TKA | To assess range of motion a Standard Goniometer will be used. Measurements will be obtained after 3, 6, 12 months | 3; 6; 12 months | 
| Change of Pain after kinematic vs mechanical aligned TKA | The pain will be measured with the Visual Analog Scale (VAS), ranging from 1 to 10. 1 is meaning no pain, 10 is meaning the worst pain imaginable. | 3; 6; 12 months | 
| Change of Function after kinematic vs mechanical aligned TKA (OKS) | Function of the artificial joint will be assessed by the use of the Oxford Knee Score (OKS). The OKS is a patient reported outcome measure that consists of 12 questions about an individual's activities of daily living and how they have been affected by pain after total knee arthroplasty. All questions are scored from 0-4 where four is the best outcome and total scores range from 0 (worst outcome) to 48 (best outcome). | 3; 6; 12 months | 
| Change of Function after kinematic vs mechanical aligned TKA (WOMAC) | Function of the artificial joint will be assessed by the use of the Western Ontario and McMaster Universities Arthritis Index Score (WOMAC). The WOMAC survey is comprised of 24 items divided into three subscales: Pain (5 items), stiffness (2 items), and physical function (17 items). Patients are asked a range of questions about their ability to carry out daily activities such as using the stairs, rising from sitting, lying in bed and conducting light or heavy domestic duties. All the items are scored on a scale of 0-4 (lower scores indicate lower levels of symptoms or physical disability). Values are summed up for a combined WOMAC score. | 3; 6; 12 months | 
| Change of Function after kinematic vs mechanical aligned TKA (KSS) | Function of the artificial joint will be assessed by the use of the Combined Knee Society Score (KSS). The KSS has a Knee Score section (7 items) and a Functional Score section (3 items). Both sections are scored from 0 to 100 with lower scores being indicative of worse knee conditions and higher scores being indicative of better knee conditions. | 3; 6; 12 months |