Fluoroscopic Analysis of Total Knee Replacement With a Kinematic Retaining or a Posterior Stabilized Design

Study Overview
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Brief Summary
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The aim of this study is to evaluate the in vivo kinematics of TKA performed with two different prosthesis: a kinematic retaining (Physica KR) and a posterior-stabilized (Physica PS) design by means of fluoroscopic analysis during activities of daily living (rising from a chair, stairs climbing, leg extension). In comparison with asymptomatic knee. Patterns of femoral rollback will be analyzed to assess if they are motor-task dependent and correlated with clinical outcomes.

Official Title
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In Vivo Kinematic Analysis of Total Knee Replacement With a Kinematic Retaining or a Posterior Stabilized Design During Activities of Daily Living

Conditions
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Total Knee Replacement

Intervention / Treatment
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* Device: Physica KR
* Device: Physica PS


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Patients submitted to Total knee arthroplasty (TKA) with Physica KR or PS; Patients with an appropriate initial fixation and stability of the knee prosthesis; Patients achieving a minimum flexion of 100° or a Knee Society Score (KSS) ≥ 65 (fair/good postoperative outcome) at 6-month follow-up; Patients affected by primary or secondary Osteoarthritis (OA) before surgery; Patients who understand the requirements of the study and are willing and able to comply with activities required for fluoroscopic examination; Patients who have signed the Ethics Committee approved study-specific Informed Consent Form. Exclusion Criteria: Patients with misalignment or axial malrotation of the knee prosthesis; Patients not able to achieve a minimum flexion of 100° or with a KSS Knee Score ≤ 65 points at 6-month follow-up; Patients who had or have planned a surgery on their uninvolved knee within a year; Muscular insufficiency or absence of muscololigamentous supporting structures required for adequate soft tissue balance; Patients who have significant neurological or musculoskeletal disorders or disease that may adversely affect gait and compromise functional recovery and evaluation; Patients who have neuromuscular or neurosensory deficit which would limit the ability to assess the performance of the device; Any psychiatric illness that would prevent comprehension of the details and nature of the study; Participation in any experimental drug/device study within the 6 months prior to the screening visit Female patients who are pregnant, nursing, or planning a pregnancy due to x-rays exposition.
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: Basic Science
Allocation: Non-Randomized
Intervention Model: Parallel Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Other: Physica KR<br>Patients who have received a Physica KR total knee implant. | Device: Physica KR<br>* Kinematic retaining total knee implant<br>|
| Other: Physica PS<br>Patients who have received a Physica PS total knee implant. | Device: Physica PS<br>* Posterior stabilized total knee implant<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Assessment of the roll-back mechanism measured with the tibio-femoral contact points at different degrees of flexion | Using a software to replicate the movement using Computer-aided design (CAD) models. The movement is studied and the distance made by the femur on the tibia is calculated giving the information of the roll back. | 6 months |