Classification Scheme of Sanders et al for Intraarticular Fractures of the Calcaneus As Seen on CT Scan

 

CT images:

(1) Coronal sections are taken of the calcaneus (cross sections show the posterior aspect as inferior, the posterior articular surface to the talus in the midpoint coming towards the viewer, and the anterior articular surface for the talus superior).

(2) The section used for classification is the one through the widest undersurface of the posterior facet of the talus.

(3) A line is drawn perpendicular to the vertical axis of the image, running from the lateral to medial aspect at the level of the middle and posterior articular surfaces.

(4) 3 equidistant lines are drawn through the line from #3, separating the view into 4 sections. The lines run diagonally towards the medial surface.

 

The 3 lines:

(1) A – defines the lateral column: line runs to a point on the medial surface halfway between the posterior aspect of the calcaneus and the line drawn in #3.

(2) B – defines the central column: line runs to a point on the medial surface one thirds of the distance between the posterior aspect of the calcaneus and the line drawn in #3

(3) C – defines the medial column: the line runs almost vertically to the point where the tuberosity for the medial articular surface arises.

 

Elements for classification:

(1) nondisplaced vs displaced

(2) number of fracture lines with fragments

Fracture Type	Fracture Lines	Number of Fragments	Type
nondisplaced	>= 1	>=2	I
displaced	1 alone A	2	IIA
displaced	1 along B	2	IIB
displaced	1 along C	2	IIC
displaced	2 along A and B	3	III AB
displaced	2 along A and C	3	III AC
displaced	2 along B and C	3	III BC
displaced	3	4	IV
comminuted	>= 3	>= 4	IV

 

Outcome:

(1) Type I fractures have an excellent outcome

(2) Type IV tend to have a poor outcome

(3) The experience and expertise of the surgeon is important in deciding the outcome for Types II and III.