Talar Body Fracture

Definition

 

Body Fracture

- fracture line exits inferior surface behind lateral process

- into posterior facet

- intra-articular body fracture

 

Neck Fracture

- fracture line exits inferior surface anterior to lateral process

- in front of sinus tarsi

- extra-articular neck fracture

 

Types

 

1.  Shear

2.  Crush

3.  Posterior Process

4.  Lateral Process

5.  Talus Head

 

1.  Shear

 

Boyd & Knight classification

- coronal or sagittal 

- horizontal

 

Epidemiology

 

13-20% of all talus fractures

 

Issues

 

Involves both AJ and posterior facet STJ

 

CT Talar Dome FractureCT Talar Dome Fracture 2

 

Prognosis

 

A.  50% develop post-traumatic arthritis

 

B.  25-100% AVN

- Usually patchy and so avoid collapse

 

Management

 

Undisplaced

- POP

 

Displaced 

- ORIF 

- either medial or lateral approach

- may need medial or lateral malleolar osteotomy

 

Talar Dome ORIF APTalar Dome ORIF Lateral

 

Talar Dome ORIF APTalar Dome ORIF LateralTalar Dome ORIF Non Union

 

Nonunion

 

Talus Body Nonunion CTTalus Body Nonunion CT2Talus Body Nonunion MRI

 

Talus Body Nonunion ORIF 1Talus Body Nonunion ORIF 2

 

2.  Crush

 

High energy

- associated injuries common

- prognosis as above

 

Management

- as above 

 

3.  Posterior Process Fractures

 

Anatomy

 

Composed of Posterolateral & Posteromedial tubercles

- separated by sulcus for FHL

- lateral larger than medial 

 

PL tubercle

- size variable

- Superior surface non articular, attaches PTFL

- Inferior surface in continuity with posteror articular surface of Talus

 

PM tubercle

- also varies in size

- deep & superficial Deltoid ligaments attach

 

Os Trigonum

- accessory bone seen in association with PL tubercle of talus

~ 50% of feet

- may be unilateral or bilateral

- may be fused to talus or calcaneus 

- relationship to PL tuberosity varies from complete separation to fusion

 

Os TrigonumTalus Posterior Tubercle Synchondrosis

 

Mechanism

 

A.  Forced PF 

- impingement especially ballet / soccer

 

B.  Excess DF 

- increased tension on PTFL with avulsion

 

Examination

 

Tender posteriorly

Crepitus with PF

Pain with motion of Hallux in groove

 

DDx 

 

Lateral process fracture

Fracture of fused os trigonum

Disruption of synchondrosis of os to talar body

 

Investigation

 

Xray

 

Talus Posterior Process Fracture

 

Bone Scan / CT useful in Dx

 

Talus Posterior Process Fracture CT

 

Management

 

Same for medial & lateral

- conservative initially

 

Persistent symptoms >6/12 

- excision of fragement

- posteromedial or posterolateral approach

- Persistent problems from non-union not uncommon 

 

4.  Lateral Process Fractures

 

Talus Lateral Process FractureTalus Lateral Process Fracture CT

 

Eponymous name

 

Snowboarder's fracture

 

Anatomy

 

Wedge shaped prominence

- most lateral aspect of talar body

- point of attachment of lateral talocalcaneal, cervical, bifurcate & ATFL

- fracture involves talofibular and STJ

 

Mechanism 

 

Acute dorsiflexion & inversion of foot

- most are avulsion fracture

 

Clinical

 

Identical to lateral ankle sprain

 

X-ray

 

Best seen on mortise view

 

Lateral Process Fracture

 

Management

 

Depends on size and displacement

 

1.  Large and non displaced

- non operative

 

2.  Large and displaced

- ORIF

 

3.  Comminuted

- non operative

- excise if problematic 

 

lateral process comminuted

 

5.  Talus Head Fractures

 

Talar Head FractureTalar Head Fracture CT

 

Epidemiology

 

< 10% of all talus fractures

- rare

- often missed

 

Pathology

 

Disability via involvement articular surface 

- late TNJ arthritis

- associated with subluxation / dislocation of transverse tarsal joints

 

Types

 

1. Compression fracture

- impaction injuries with force through navicular to compress head

- hyperdorsiflexion

- may also produce compression fracture of navicular

 

2. Shear fracture

- secondary to inversion injury

- causes midtarsal adduction with navicular tearing off portion head

 

Management

 

Non-displaced 

- cast NWB

 

Displaced 

- ORIF via medial approach

- if extremely comminuted consider TNJ arthrodesis