Anatomy
Facets | Tuberosities | Process |
---|---|---|
Posterior facet / subtalar joint | Posterior - tendoacilles | Anterior - calcaneocuboid joint |
Middle facet (sustenaculum tali) | Medial - adductor hallucis, plantar fascia | |
Anterior facet | Lateral - abductor digiti minimi |
Etiology
Usually fall from height - calcaneum driven up against talus
Epidemiology
10% bilateral
10% associated with lumbar spine fracture
Fracture patterns
Primary fracture line
- lateral process of talus driven into crucial angle
- starts at lateral wall near tarsal sinus
- passes obliquely across posterior facet
- exits at medial wall posterior to sustentaculum tali
Secondary fracture lines
- passes immediately behind the posterior facet of the subtalar joint
- exits posterior to posterior facet & anterior to tendoachilles insertion
- creates thalamic portion containing posterior facet
Common fracture fragments
Sustanacular | Superolateral | Lateral wall | Posterior tuberosity |
---|---|---|---|
Superomedial |
Lateral fragment of posterior facet
|
Tongue fracture | |
Attached to talus by deltoid ligament | Thalamic fragement | Secondary fracture line exits below tendoacilles |
X-ray Views
Lateral | Oblique view |
---|---|
Bohler's angle Crucial angle of Guisane |
Calcaneocuboid joint |
Harris axial view | Broden's view |
---|---|
45o axial of heel - normally hindfoot 10o of valgus - assess varus malalignment & heel width |
Internally rotate foot 45 degrees - ankle neutral initially - plantar flex the foot 10° increments from 10° to 40
Useful intra-op to assess congruency of subtalar joint |
Xray Angles
Bohler's angle (20-40°)
Lateral xray
Highest point anterior process - highest point on posterior facet - highest point on tuberosity
- represents the height of the calcaneus
- normal 20-40°
Angle of </=0° is associated with a poor outcome
Normal Bohler's angle
Calcaneal fracture with Bohler's angle < 0
Crucial Angle Gissane (120-140°)
Lateral xray
Posterior facet of calcaneum - anterior process of calcaneum
Normal angle of Gissane
Reduced angle of Gissane after fracture
CT scan
Coronal | Sagittal | Axial |
---|---|---|
Posterior facet / number of fragments Sustenaculum tali Heel widening |
Bohlers angle Posterior facet depression / angulation |
Calcaneocuboid joint Sustenaculum tali |
Sanders Coronal CT Classification
Posterior facet on coronal CT
- number of longitudinal fracture lines (Type II - IV)
- location of fractures (A: lateral, B: central, C: medial)
Type I | Type II | Type III | Type IV |
---|---|---|---|
Undisplaced |
Two parts Displaced > 2 mm |
Three parts Displaced > 2 mm |
Highly comminuted |
Non operative | ORIF | ORIF / fusion | Primary fusion |