Pathoanatomy of the Tongue-Type Calcaneus Fracture: Assessment Using 2- and 3-Dimensional Computed Tomography.

OBJECTIVE

To define the pathoanatomy of the tongue-type calcaneus fracture and assess the appropriateness of percutaneous techniques in addressing all planes of deformity in this injury.

DESIGN

Retrospective cohort.

SETTING

ACS Level I trauma center.

PATIENTS/

PARTICIPANTS

Fifty-six displaced Sanders 2B and 2C tongue-type calcaneus fractures identified from an initial cohort of 1118 calcaneus fractures treated over a 16-year period.

MAIN OUTCOME MEASUREMENTS: We reviewed cross-sectional imaging and documented the presence of a varus/valgus (coronal plane) or adduction/abduction (axial plane) position of the tongue fragment in relation to the intact posterior facet, with greater than 10 degrees of angulation being diagnostic of displacement.

RESULTS

When assessing for displacement and angulation in the coronal plane, 98% of tongue fragments were either in a position of valgus (77%) or neutral (21%), with a mean valgus angulation of 17.3 degrees. In the axial plane, 98% of tongue pieces were in a position of adduction (64%) or neutral (34%), with an average angulation into adduction of 15.0 degrees. Sanders 2B fractures were more likely to be in a position of valgus and adduction than those of 2C fractures.

DISCUSSION: The tongue-type calcaneus fracture most often displaces into a position of plantarflexion, valgus, and adduction. Knowledge of this deformity may aid in achieving successful closed reduction when using the Essex-Lopresti maneuver or other less invasive techniques.