The Hindfoot Alignment View

TLDR

The study introduces a modified Cobey method for radiographically imaging hindfoot coronal alignment. The technique estimates the moment arm between the leg’s weightbearing axis and the heel’s contact point using the new hindfoot alignment view. In 57 asymptomatic adults, the tibial weightbearing line lies within 8 mm of the lowest calcaneal point in 80 % and within 15 mm in 95 %, and the method shows high reliability (ICC = 0.97), supporting its use for assessing complex hindfoot malalignments.

Abstract

A modification of Cobey's method for radiographically imaging the coronal plane alignment of the hindfoot is described. Using this view, we estimated the moment arm between the weightbearing axis of the leg and the contact point of the heel. Normative data on 57 asymptomatic adult subjects are presented. The weightbearing line of the tibia falls within 8 mm of the lowest calcaneal point in 80% of subjects and within 15 mm of the lowest calcaneal point in 95% of subjects. The technique for measuring coronal plane hindfoot alignment is reliable, with an interobserver correlation coefficient of 0.97. This radiographic technique should help in the evaluation of complex hindfoot malalignments.