The Axis of the Ankle Joint and its Importance in Subtalar Arthrodesis

The direction of the axis of the ankle joint is described somewhat \-ariously in the literature but generally it is described as almost entirely transverse in relation to the sagittal plane of the normal foot.Hnrnc.ft, A'apier & Hicks csamincd the axis of the ankle joint in greater detail.Barnrf t 6 Sapicr esaniincd 152 cartilage-covercd talus bones and found that the medial profile of the trochlea is coniljosed of an anterior arc with a small radius and a posterior arc with a large radius, Lvhilc the lateral profile consists of a single arc with a iiiediuni sized radius.t Fig. 1 ) .In moving the foot dorsally to the 0-position iboth in the dorsal and plantar direction in this dorsal area of movement), it is the anterior part of the trochlea with the sharp medial arc which is in contact with .hvtibia.From this Brrrnctt & Sapicr concluded that these movements must occur around an axis lvhich is higher medially than laterally.1 Reprinted after correctinn from The Proceedings of the Nnrdisk Orthopedisk Fiirening:, 301h A s s e m h l ~ in Oslo where the article contained snme confusing errors.