Varus-valgus native knee laxity in extension displays an almost rectangular pattern and does not correlate with lower...

Area of Science:

• Orthopedics
• Biomechanics
• Radiology

Background:

• Total knee arthroplasty (TKA) requires precise ligament balance for optimal outcomes in knee osteoarthritis management.
• Existing research on ligament balance shows variability due to differing methodologies and populations, necessitating further investigation.

Purpose of the Study:

• To assess varus-valgus ligament laxity in healthy Japanese knees.
• To examine the relationship between ligament balance and lower limb alignment in this population.

Main Methods:

• Utilized stress radiographs on 64 knees from 33 healthy Japanese adults to quantify varus-valgus laxity.
• Measured mechanical hip-knee-ankle angle, medial proximal tibial angle, and lateral distal femoral angles via digital long-leg radiographs.

Main Results:

• Mean varus laxity (3.6°±1.3°) was significantly greater than mean valgus laxity (2.9°±1.0°) (p<0.0001).
• No significant correlation was found between ligament balance (varus/valgus laxity) and lower limb alignment parameters.

Conclusions:

• Healthy Japanese knees exhibit a slight predominance of varus laxity over valgus laxity.
• Lower limb alignment does not appear to influence ligament balance, a key consideration for patient-specific TKA strategies.