Degree of deformity (Category)

Based on the value of the angles

Based on the conjugate deformity

$\left|OS\right|=\sqrt{{\text{HVA}}^2+{\text{IMA}}^2}$ , (˚)

HVA, (˚)

IMA, (˚)

The finding is normal (FN)

<15˚

<9˚

$\left|OS\right|<{17.5}^{\circ }$

Mild Deformity (MD)

from 15˚ to 30˚

from 9˚ to 13˚

${17.5}^{\circ }\le \left|OS\right|<{32.7}^{\circ }$

Moderate Deformity (MoD)

from 30˚ to 40˚

from 13˚ to 20˚

${32.7}^{\circ }\le \left|OS\right|<{44.7}^{\circ }$

Severe Deformity (SD)

40˚ and above

20˚ and above

$\left|OS\right|\ge {44.7}^{\circ }$