Matched Pair Study - Kinematic vs Mechanical Alignment

Study Overview
=================
Brief Summary
-----------------
The aim of this study is to evaluate postoperative knee function after total knee arthroplasty performed according to the anatomical alignment and compare these results to those of a matched historical cohort of patients operated with mechanical alignment.

Detailed Description
-----------------
The 25 patients, of the Kinematic group, are prospectively enrolled. While, the data of patients of the Mechanical group, are retrospectively collected from an historical collection.

Official Title
-----------------
Matched Pair Study to Assess Influence of Kinematic Versus Mechanical Alignment in Total Knee Replacement

Conditions
-----------------
Osteoarthritis, Knee, Joint Disease

Intervention / Treatment
-----------------
* Procedure: Kinematic alignment
* Procedure: Mechanical alignment
* Device: GMK Sphere®


Participation Criteria
=================
Eligibility Criteria
-----------------
Inclusion Criteria: Patients presenting with disease that meets the indications for use for Medacta implants defined by this study (on-label use). Patients necessitating primary Total Knee Replacement Patients who are willing and able to provide written informed consent for participation in the study. Written informed consent must be obtained prior to the patient's surgery. Exclusion Criteria: Those with one or more medical conditions identified as a contraindication defined by the labeling on Medacta implants used in this study. Previous osteotomy around the knee Ligament instability likely to require higher level of constraint Previous infection or inflammatory disease Extraarticular deformities for which a femoral intramedullary guide rod can't be inserted into the canal and use of Computer Assisted Orthopaedic Surgery (CAOS) or Patient Specific Instrumentation (PSI) is required.
Sexes Eligible for Study
-----------------
All

Accepts Healthy Volunteers
-----------------
No

Study Plan
=================
How is the study designed?
-----------------

Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Kinematic alignment with GMK Sphere®<br>Patients enrolled prospectively with surgeries planned to get kinematic alignment | Procedure: Kinematic alignment<br>* The principle for kinematically aligning the femoral component is to remove the correct amount of bone and cartilage from the distal and posterior femur after accounting for wear and saw blade kerf, so that the total thickness of the missing and removed tissue matches the thickness of the femoral component.<br>Device: GMK Sphere®<br>* The GMK Sphere® is a total knee prosthesis . The design of the GMK Sphere® is characterized by a spherical medial femoral condyle and an asymmetrical fixed tibial UHMWPE polyethylene insert with a concave spherical medial compartment.<br>|
| Mechanical alignment with GMK Sphere®<br>Historical group who had mechanical alignment, match-paired with the prospective group | Procedure: Mechanical alignment<br>* Classic mechanical alignment (MA) in total knee arthroplasty (TKA) is meant to co-align the prosthetic components to the mechanical axes of the femur and tibia and restore neutral overall limb alignment<br>Device: GMK Sphere®<br>* The GMK Sphere® is a total knee prosthesis . The design of the GMK Sphere® is characterized by a spherical medial femoral condyle and an asymmetrical fixed tibial UHMWPE polyethylene insert with a concave spherical medial compartment.<br>|

What is the study measuring?
-----------------
Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Compare clinical outcomes of mechanical vs kinematic with new Knee Society Score | The new KSS (from the publication of 2011, Giles R. Scuderi MD The New Knee Society Knee Scoring System Clin Orthop Relat Res (2012) 470:3-19) includes a part filled by the surgeon and one by the patient. The first outcome is focused on the Functional Activities subscore, excluding the Discretionary knee activities. The maximum is 85 points while the minimum is -10 points. The Functional Activities score includes 3 subscores: WALKING AND STANDING (min -10, max 30), STANDARD ACTIVITIES (min 0, max 30) and ADVANCED ACTIVITIES (min 0, max 25) | 1-year follow-up | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Patient functional improvement, satisfaction and symptoms | The functional improvement, satisfaction and symptoms is the sum of the following subscores of the new KSS: Functional Activities, Patient Satisfaction and Symptoms | 1-year follow-up | 
| Residual deformity | The residual deformity is evaluated by long axis Xray analysis: HKA angle | 1-year follow-up | 
| Flexion-extension contracture | The flexion-extension contracture is evaluated by a subscore of the new KSS: Joint motion | 1-year follow-up | 
| Self-reported pain, function and stiffness | These aspects are evaluated through KOOS score | 1-year follow-up | 
| Ability to forget about artificial joint | Through the use of the Forgotten Joint Score | 1-year follow-up |