Lateral-stabilized total knee arthroplasty enables design-specific kinematic behavior consistent with key...

Area of Science:

• Orthopedic Surgery
• Biomechanical Engineering
• Medical Device Design

Background:

• Anterior knee pain (AKP) is a common issue post-total knee arthroplasty (TKA).
• Non-physiological knee kinematics and patellar maltracking contribute to TKA dissatisfaction.
• Incorporating in vivo knee kinematics into TKA design may reduce adverse outcomes.

Purpose of the Study:

• To assess the clinical outcomes of a new TKA system (5C® LATic) designed using in vivo knee kinematics.
• To evaluate if the new TKA design improves knee joint motion and reduces anterior knee pain.

Main Methods:

• Retrospective study of eleven patients treated with the 5C® LATic TKA system.
• In vivo fluoroscopic measurements of 3D TKA motion during a loaded lunge from extension to maximal flexion at 12 months post-surgery.
• Patient-reported outcome measures including KSS, FJS, and HFKS questionnaires were administered.

Main Results:

• The 5C® LATic system exhibited lateral stability and reduced anterior medial compartment movement, with femoral component external rotation.
• Consistent posterior movement of the femoral component's frontal aspect was observed until maximal flexion.
• All patients reported significant improvements in questionnaire scores and high overall satisfaction with the prosthesis.

Conclusions:

• The study demonstrates expected design-based kinematics for the 5C® LATic TKA system.
• The observed kinematics, including external rotation and posterior femoral movement, may improve patellar tracking.
• This improved patellar tracking is a key factor in potentially reducing anterior knee pain after TKA.