Lateral view relationships:
Calcaneal inclination angle:
Angle formed by the intersection of the calcaneal inclination axis and the plane of support. Normally 15 to 25 degrees.
Talar declination angle:
Angle formed by the intersection of the plane of support and the collum tali axis. Normally about 21 degrees.
First metatarsal declination angle:
Angle formed by the intersection of the bisection of the first metatarsal and the plane of support.
Appears as a ‘lazy’ S shape formed by the articulations of the talonavicular and calcaneocuboid joints – should appear smooth and unbroken. ‘Breaks” anteriorly in a pronated foot.
Appears oval shaped in normal foot. Appears obliterated in pronated foot. Appears as a “bullet hole” in the supinated foot.
• relationship between line representing posterior aspect of calcaneus and calcaneal inclination line
• normally 44-64 degrees
• useful in evaluation of Haglund’s deformity
• relationship between two lines on lateral x-ray:
• normally 25-40 degrees
• used to assess the degree of intra-articular depression in calcaneal fractures
• 20 degrees is accepted as the lower limit cut off point to reduce the number of false positives