Hindfoot FracturesHindfoot Fractures

Moritz HaagerMoritz Haager

July 8, 2004July 8, 2004

Jeez, I sure hope I don’t bust my hindfoot..

What articulations comprise the What articulations comprise the ankle joint complex?ankle joint complex?

What articulations comprise the What articulations comprise the ankle joint complex?ankle joint complex?

Talocrural jointsTalocrural joints1.1. Distal tibia – talusDistal tibia – talus2.2. Medial malleolus – talusMedial malleolus – talus3.3. Lateral malleolus – talusLateral malleolus – talus4.4. Distal tibia – distal fibula Distal tibia – distal fibula

(distal tibiofibular joint)(distal tibiofibular joint)Collectively allow dorsiflexion Collectively allow dorsiflexion and plantarflexion and plantarflexion

Subtalar jointsSubtalar joints5.5. Talus – CalcaneusTalus – Calcaneus

Contributes to inversion and Contributes to inversion and eversioneversion

Hence the talus & calcaneus Hence the talus & calcaneus are key to ankle functionare key to ankle function

1

23

4

5

AP RadiographAP Radiograph

AdequacyAdequacy– Fibula & tibia above Fibula & tibia above

talustalus– Open medial clear Open medial clear

space space

> 10 mm

Lateral RadiographLateral Radiograph

AdequacyAdequacy– Malleoli superimposedMalleoli superimposed– Joint space cleary Joint space cleary

visible w/o overlapvisible w/o overlap

Look for signs of Look for signs of ankle effusionankle effusion– Lucency anterior or Lucency anterior or

posterior to joint posterior to joint capsulecapsule

Mortise ViewMortise ViewEvaluates articular surfaceEvaluates articular surfaceTechniqueTechnique– Leg is internally rotated 15 – 20Leg is internally rotated 15 – 20oo – X-ray beam perpendicular to X-ray beam perpendicular to

intermalleolar lineintermalleolar lineAdequacyAdequacy– No overlap of talar dome & joint No overlap of talar dome & joint

spacespace– Med. & lat. clear spaces openMed. & lat. clear spaces open

Articular surfaces should be parallel Articular surfaces should be parallel throughout i.e. uniform joint widththroughout i.e. uniform joint widthShould see mild (Should see mild (>>1 mm) overlap of 1 mm) overlap of tibia & fibulatibia & fibulaMedial clear space should not Medial clear space should not exceed 4 mm exceed 4 mm Lateral clear space should not Lateral clear space should not exceed 5.5 mmexceed 5.5 mm

medial clear space

lateral clear space(< 5.5 mm)

>1 mm

Talus anatomyTalus anatomy

What is the risk with talar neck fractures? Why?What is the risk with talar neck fractures? Why?

Avascular necrosisAvascular necrosis– Most of the vascular supply to body via neckMost of the vascular supply to body via neck

Neck

Talar dome or trochlea

Midfoot(Chopart joint)

Subtalar joint

BodyHead

Talar fracturesTalar fractures

Minor talar fractures Minor talar fractures – Chip and avulsion fractures of neck ,head, and body. Chip and avulsion fractures of neck ,head, and body. – Usually same mechanism as ankle sprains Usually same mechanism as ankle sprains

Talar neck fracturesTalar neck fractures– 50% of major talar injuries.50% of major talar injuries.– extreme dorsiflexion force (aviator’s astralagus)extreme dorsiflexion force (aviator’s astralagus)– Frequent associated fracturesFrequent associated fractures– Hawkins classificationHawkins classification

Talar body fractures Talar body fractures – 23% of all talar fractures (including minor fractures) 23% of all talar fractures (including minor fractures) – Major talar body fractures are uncommon Major talar body fractures are uncommon

usually axial loading (e.g. falls)usually axial loading (e.g. falls)

Talar head fracturesTalar head fractures– Uncommon (5-10%)Uncommon (5-10%)– compressive force transmitted up through the talonavicular joint compressive force transmitted up through the talonavicular joint

applied on a plantarflexed foot applied on a plantarflexed foot

Hawkins Classification of Talar Hawkins Classification of Talar Neck FracturesNeck Fractures

Type 1: = nondisplaced; Type 1: = nondisplaced; Type 2: subtalar subluxationType 2: subtalar subluxationType 3: dislocation of the talar body (50% open #’s)Type 3: dislocation of the talar body (50% open #’s)Type 4: dislocation of the talar body & distraction of the Type 4: dislocation of the talar body & distraction of the talonavicular joint. talonavicular joint. – Fracture type influencesFracture type influences management & prognosis management & prognosis

Calcaneal anatomyCalcaneal anatomy

Posteriortuberosity

Anteriorprocess

apex of posterior facet

Sustenaculum tali

Lateral malleolus

Axial (Harris) ViewAxial (Harris) View

Sustenaculumtali

Lateral malleolus

Posteriortuberosity

Bohlers AngleBohlers Angle

apex of posterior facet

Posteriortuberosity

apex ofanterior process

Calcaneus FracturesCalcaneus Fractures

ClassificationClassification– Compression #’sCompression #’s– Posterior tuberosity #’sPosterior tuberosity #’s– Anterior process #’sAnterior process #’s– Sustenaculum tali #’sSustenaculum tali #’s

High energy mechanism High energy mechanism associated associated injuriesinjuries– 20% will have vertebral fractures20% will have vertebral fractures

Chip (osteochondral) fracture

Talus fracture

Type 3 talar neck fracture

Normal

Type 2 talar fracture

Oblique ViewOblique View

Anteriorprocess #

Posterior tubercle #

Key ConceptsKey Concepts

Plain films tend to underestimate hindfoot Plain films tend to underestimate hindfoot fractures fractures – often require CT or MRI for better evaluationoften require CT or MRI for better evaluation

Calcaneal fractures are Calcaneal fractures are – frequently bilateral frequently bilateral – associated with other injuriesassociated with other injuries

Abnormal Bohlers angle may be only clueAbnormal Bohlers angle may be only clue

Talus fractures are at risk for AVNTalus fractures are at risk for AVN

QuestionsQuestions