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

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

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.

Inclusion Criteria:

1. Patients submitted to Total knee arthroplasty (TKA) with Physica KR or PS;
2. Patients with an appropriate initial fixation and stability of the knee prosthesis;
3. Patients achieving a minimum flexion of 100° or a Knee Society Score (KSS) ≥ 65 (fair/good postoperative outcome) at 6-month follow-up;
4. Patients affected by primary or secondary Osteoarthritis (OA) before surgery;
5. Patients who understand the requirements of the study and are willing and able to comply with activities required for fluoroscopic examination;
6. Patients who have signed the Ethics Committee approved study-specific Informed Consent Form.

Exclusion Criteria:

1. Patients with misalignment or axial malrotation of the knee prosthesis;
2. Patients not able to achieve a minimum flexion of 100° or with a KSS Knee Score ≤ 65 points at 6-month follow-up;
3. Patients who had or have planned a surgery on their uninvolved knee within a year;
4. Muscular insufficiency or absence of muscololigamentous supporting structures required for adequate soft tissue balance;
5. Patients who have significant neurological or musculoskeletal disorders or disease that may adversely affect gait and compromise functional recovery and evaluation;
6. Patients who have neuromuscular or neurosensory deficit which would limit the ability to assess the performance of the device;
7. Any psychiatric illness that would prevent comprehension of the details and nature of the study;
8. Participation in any experimental drug/device study within the 6 months prior to the screening visit
9. Female patients who are pregnant, nursing, or planning a pregnancy due to x-rays exposition.