Single-Leg Weight-Bearing Reveals Hidden Varus Deformity in Knee Osteoarthritis

Background/Objectives: Accurate radiographic assessment of coronal alignment is essential for corrective osteotomies and knee arthroplasty. However, conventional bilateral weight-bearing radiographs may underestimate varus alignment under single-leg weight-bearing. This study aimed to describe the increase in knee varus alignment between bilateral and single-leg weight-bearing stances and to evaluate the factors associated with this increase.

Methods

Standardized long-leg radiographs were obtained in bilateral and single-leg weight-bearing stances using a digital radiography system. ΔVarus was defined as the difference between single-leg bearing and bipedal varus angles (single-leg bearing varus—bipedal varus) and was reported in degrees (°). Patients were stratified by dominant lower extremity and sex for subgroup analyses.