总结膝内翻患者股骨侧弓角的测量方法。

选取2014年1月至2018年6月在上海中医药大学附属曙光医院骨科就诊的膝内翻膝关节骨关节炎患者，回顾患者既往下肢全长X线、对比膝关节内翻后股骨X线片，确定最相似的2张股骨X线片，记录对应的X线投照旋转角度。

膝关节骨关节炎膝内翻患者，投照股骨X线的适宜旋转角度：10°≤内翻角度<20°组：中位数10°(9°，12°)；20°≤内翻角度<30°组：中位数16°(14°，20°)；内翻角度≥30°组：中位数24°(21°，25°)。

对于膝内翻的骨关节炎患者，摄股骨X线时，投照角度适当外旋，可更准确测得股骨侧弓角。

To explore a method for measuring the bowing angle of the femur in patients with knee varus.

The patients with knee varus knee osteoarthritis treated in the department of orthopedics, Shuguang Hospital affiliated to Shanghai university of traditional Chinese medicine from January 2014 to June 2018 were selected. The previous full-length X-ray films of the lower extremities were compared with the femoral X-ray of the varus knee. Two of the most similar femur X-ray films were determined, and the corresponding rotation angle of the projection was recorded.

The suitable rotation angle of the femoral X-ray in knee osteoarthritis patients with knee varus were as follows: the group of 10°≤varus angle<20°∶ 10°(9°, 12°); the group of 20°≤inversion angle<30° ∶ 16°(14°, 20°); inversion angle≥30°group 24°(21°, 25°).

For the osteoarthritis patients with genu varus, the lateral arch angle of the femur can be more accurately measured by appropriate external rotation when taking the femoral X-ray film.