Talar neck fractures

 

 

Epidemiology

 

< 1% of all fractures

 

Etiology

 

Fall from height

 

Dorsiflexion injury - neck of talus strikes the anterior tibia

 

Supination injury - neck of talus strikes medial malleolus

 

Anatomy

 

No muscular attachments

 

60% covered by articular cartilage

 

 

 

 

Body	Neck	Head	Inferior facets
Superior cartilage for tibia	Angles medially 10 - 44 Angles plantar 5 - 50	Articulates with navicular	Posterior / middle / anterior
Articulate with medial & lateral malleolus	Conduit for blood supply to body	Supported by spring ligament	Articulate with calcaneal facets below

 

Blood Supply

 

 

 

Posterior tibial artery	Anterior tibial artery	Peroneal artery
A. Artery of tarsal canal - body	Dorsalis pedis	Artery of sinus tarsi
B. Deltoid branch - medial body	Head and neck of talus	Head and neck of talus

 

Hawkins classification

 

Progressive injury

 

	Type I	Type II	Type III	Type IV
Definition	Fracture of neck Undisplaced	Fracture displaces Subluxation / dislocation of the subtalar joint	Talar body dislocates from ankle joint posteromedially	Talar head dislocates from navicular joint
Incidence	21%	43%	31%	5%

 

Type I:  Minimally displaced

 

 

Type II: Disruption of subtalar joint

 

Type IIa: subtalar joint subluxed

 

Type IIb: subtalar joint dislocated

 

Type III: Talar body dislocated from ankle joint

 

 

 

Type IV: Talar head dislocated from talonavicular joint

 

 

Compound wounds

 

 

Immediate management

 

Reduce fractures

 

 

Closed reduction technique

- flex knee to relax gastrocnemius

- traction on plantarflexed foot to realign head and body

- varus / valgus correct as required

 

Irreducible fractures / Extruded Talus

 

Options

- anteromedial / anterolateral approach

- posteromedial approach

 

 

Posteromedial approach for open reduction of dislocated talar body

 

Non-operative Management

 

Indication

 

Type I

 

Xray / CT

 

Ensure no displacement / malalignment

 

Managment

 

6 - 8 weeks in cast NWB

 

Operative Management

 

Timing of Surgery

 

Does early reduction prevent AVN?

 

Vallier et al JBJS Am 2004

- 102 patients with ORIF talar neck fractures

- no evidence that surgical delay increased AVN

- AVN associated with neck comminution and open fractures

- recommendation to wait for swelling to subside

 

Best to delay to allow soft tissues to settle

 

Approach

 

2 incision technique with > 7 cm skin bridge

 

1.  Anteromedial approach

 

Technique

- from medial malleolus to talonavicular joint / base first metatarsal

- protect great saphenous vein and saphenous nerve

- between Tibialis anterior and tibialis posterior tendon

- preserve deep deltoid for blood supply

- +/- medial malleolar osteotomy to access talar dome

 

AO surgery reference anteromedial approach talus

 

2. Anterolateral approach

 

Technique

- based on 4th metatarsal

- anterolateral border fibular to 4th metatarsal

- protect branches superficial peroneal nerve

- between EDL and peroneus tertius

- extensor tendons medially

- divide and elevate EDB, retract laterally

- excise sinus tarsi fat pad

- 7 cm skin bridge from anteromedial approach

 

AO surgery reference anterolateral approach talus

 

Anatomical reduction + fixation

 

1. Remove loose bodies from subtalar joint

 

 

2. Reduction - avoid varus and shortening medial neck

- often medial comminution

 

 

 

 

Canale view

- evaluates talar neck

-

- beam angled

- look for medial shortening / varus

 

ORIF

 

AO surgery foundation talar neck ORIF

 

Vumedi dual approach to talus video

 

Vumedi talar neck fixation techniques video

 

Cannulated screws

 

Xrays

 

AP	Lateral	Canale View
Entry point of the screws	Evaluate neck reduction	Evaluates the neck reduction
Lateral off articular surface Medial through articular cartilage	Depth of screws	Beam angled 75o to foot Foot 15o pronated

 

1. Retrograde (anterior to posterior) into posterior talus body

 

A. Lateral screw

- insert proximal to articular surface of head on lateral side

- bone is very curved here

- can lag screw as usually no comminution

 

B. Medial side

- insert through articular surface

- countersunk screws through articular surface

- avoid lag screw techniques medially as may compress comminution into varus

 

AP, Canale and Lateral xray

 

Retrograde screws

 

2. Antegrade (posterior to anterior) screws

- between FHL and peroneals

- entry point lateral tubercle talus

- bury to avoid posterior impingement

 

Antegrade screws

 

Plates

 

Options

- mini fragment plates

- anatomically contoured talar neck plates

- lateral talar neck very curved

 

Paragon 28 talar neck plates pdf

 

Screw + plate

 

Devitalised Type 3 / 4 with compound wound

 

Option 1. Wash / lean / ORIF / reduce

 

 

 

Option 2: Discard / cement spacer / later fusion or total talar replacement