Changes in Parameters after High Tibial Osteotomy: Comparison of EOS System and Computed Tomographic Analysis

Area of Science:

• Orthopedic surgery
• Medical imaging technology
• Biomechanical analysis

Background:

• Medial open-wedge high tibial osteotomy (MOWHTO) can cause unintended distal tibial rotation.
• Computed tomography (CT) is standard for limb alignment but involves radiation.
• The EOS system offers low-dose 3D modeling and automated alignment measurements.

Purpose of the Study:

• To compare lower limb alignment measurements between EOS imaging and CT after MOWHTO.
• To identify factors influencing tibial deformation during MOWHTO.

Main Methods:

• Prospective enrollment of 30 patients undergoing MOWHTO.
• Pre- and post-operative measurements of femoral/tibial torsion, femorotibial rotation, and posterior tibial slope using both CT and EOS.
• Statistical analysis to compare imaging modalities and identify correlating factors.

Main Results:

• No significant differences were found between CT and EOS for tibial torsion or posterior tibial slope, pre- or post-operatively.
• No identified variables correlated significantly with changes in tibial torsion or posterior tibial slope.
• Distal tibial internal rotation was consistently observed after MOWHTO.

Conclusions:

• The EOS system is a viable alternative to CT for measuring key lower limb alignment parameters following MOWHTO.
• While distal tibial internal rotation is common after MOWHTO, its causative factors remain unidentified in this study.