Meary's angle or lateral talo-first metatarsal angle has been used to identify the apex of deformity in patients with pes cavus and pes planus on lateral weight bearing radiograph. It is the angle between line drawn from the centers of longitudinal axes of the talus and the first metatarsal.
In the normal weight-bearing foot, the midline axis of the talus is in line with the midline axis of the first metatarsal. Normally Meary's angle is 0 degree.
It can also be used to assess severity of the deformity
- angle < 15 degrees - mild deformity
- angle 15-30 degrees - moderate deformity
- angle > 30 degrees - severe deformity
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