Dynamic Alignment Analysis in the Osteoarthritic Knee Using Computer Navigation

Area of Science:

• Orthopedics
• Biomechanics
• Medical Imaging

Background:

• Lower limb alignment is crucial for knee joint function.
• Osteoarthritis (OA) alters knee mechanics, affecting alignment.
• Understanding dynamic alignment in OA knees is vital for surgical planning.

Purpose of the Study:

• To determine the dynamic coronal femoral-tibial mechanical angle (FTMA) in osteoarthritic knees.
• To investigate varus-valgus alignment patterns in relation to knee flexion.
• To utilize computer navigation for precise FTMA measurements.

Main Methods:

• Prospective observational study of 100 osteoarthritic knees undergoing navigation total knee arthroplasty (TKA).
• Measurement of FTMA in supine position at full extension, 30, 60, and 90 degrees of flexion.
• Hierarchic cluster analysis to segment FTMA data into distinct varus-valgus patterns.

Main Results:

• Osteoarthritic knees demonstrate a well-defined dynamic alignment.
• Significant kinematic variation in coronal FTMA observed between flexion and full extension.
• Clustering revealed distinct varus (5 segments) and valgus (3 segments) alignment patterns.

Conclusions:

• Dynamic coronal alignment exists in osteoarthritic knees.
• Kinematic variations in FTMA are substantial between different knee flexion angles.
• Further research is needed to assess the clinical utility of dynamic FTMA assessment in surgical decision-making.