X-ray of flat feet
Flat feet is a postural deformity in which the arches of the foot collapse, with the entire sole of the foot coming into complete or near-complete contact with the ground.
Contents
Planning
Flat feet can be diagnosed clinically, but projectional radiography ("X-ray") is helpful in uncertain cases. It can be used for severity grading, although this has little implication for treatment options.[note 1]
Diagnosis
On X-ray, flat feet can be diagnosed and graded by several measures, the most important in adults being the talonavicular coverage angle, the calcaneal pitch, and the talar-1st metatarsal angle (Meary's angle).[1] The talonavicular coverage angle is abnormally laterally rotated in flat feet.[1] It is normally up to 7 degrees laterally rotated, so a greater rotation indicates flat feet.[1] Radiographies generally need to be taken on weightbearing feet in order to detect misalignment.[2]
- Talonavicular coverage angle.jpg
Dorsoplantar projectional radiograph of the foot showing the measurement of the talonavicular coverage angle.
- Calcaneal pitch.jpg
Weight-bearing lateral X-ray showing the measurement of calcaneal pitch, which is an angle of the calcaneus and the inferior aspect of the foot, with different sources giving different reference points.[note 2] A calcaneal pitch of less than 17° or 18° indicates flat feet.[1]
- Talar-1st metatarsal angle (Meary's angle).jpg
Same lateral X-ray showing the measurement of Meary's angle, which is the angle between the long axis of the talus and first metatarsal bone.[1]
Report
Presence or absence of flat feet.
Upon request, severity can be given (Meary's angle angle 15° - 30° is considered moderate flat foot, and greater than 30° severe flat foot.[1]), otherwise it is not relevant.[note 1]
Notes
References
- ↑ 1.0 1.1 1.2 1.3 1.4 1.5 . Pes Planus. University of Washington, Department of Radiology. Last modified: 2016/08/14
- ↑ Dan J Bell and Yuranga Weerakkody. Pes planus. Radiopaedia. Retrieved on 2018-03-01.
