Lower limb alignment in healthy Japanese adults

Area of Science:

• Orthopedic surgery
• Radiology
• Biomechanical analysis

Background:

• Understanding normal lower limb alignment is critical for successful total knee arthroplasty.
• Limited data exists on the lower limb alignment of healthy Japanese populations.

Purpose of the Study:

• To investigate and quantify the lower limb alignment parameters in healthy adult Japanese volunteers.
• To establish baseline data for Japanese lower limb alignment relevant to orthopedic surgery.

Main Methods:

• Whole leg standing radiography was performed on 120 legs from 60 healthy Japanese adults (<50 years).
• Key measurements included hip knee ankle angle, constitutional varus percentage, and joint line angles.
• Data was analyzed for overall, male, and female populations.

Main Results:

• Japanese subjects exhibited a higher mean hip knee ankle angle and a higher percentage of constitutional varus compared to other populations.
• Mechanical lateral distal femoral and medial proximal tibial angles were smaller in Japanese subjects.
• A statistically significant difference was found in the medial proximal tibial angle between men and women.

Conclusions:

• Japanese individuals possess unique lower limb alignment characteristics, including a higher prevalence of constitutional varus.
• These findings enhance the understanding of Japanese-specific alignments, vital for optimizing total knee arthroplasty outcomes.
• The data provides essential reference values for preoperative planning in lower limb surgeries for the Japanese population.