Ankle Fracture

AnatomyDislocated Ankle



- 90% load through plafond to talus

- 10% load through lateral talofibular articulation




A.  Lateral Ligament Complex


ATFL (Anterior Talo-Fibular Ligament) 

- tight in plantar flexion


CFL (Calcaneo-fibular ligament)

- slopes down & back

- tight in dorsiflexion


PTFL (Posterior Talofibular Ligament)

- scissors with Posterior Tibiofibular Ligament


B.  Medial Ligaments


Superficial Deltoid (SDL)

- origin medial tibia

- broad insertion talus / calcaneum / navicular

- resists hindfoot eversion


Deep Deltoid (DDL) 

- tibiotalar

- key to stability / primary stabiliser of ankle

- resists talus ER

- if divided get abnormal ER of talus in plantar flexion


C.  Syndesmosis


Interosseous Ligament

- between AITFL and PITFL (anterior inferior and posterior inferior tibio-fibular ligament)





- DF = 30°

- PF = 45°

- Rolls & slides to produce DF/PF



- deltoid ligament acts as a checkrein

- prevents ER of talus

- causes 5° IR talus



- talus wider anteriorly 2.5 mm

- fibula moves laterally & ER to accommodate


Ramsey 1976

- 1mm talus shift = Contact area decreased by 40%

- non-physiological study

- jammed wedges in intact ankle


Ankle Fracture Classification 


No system prognostic


1.  Weber ABC


A.  Fracture distal to syndesmosis

- stable / avulsion type fracture



Weber A


B.  Fracture at level of syndesmosis

- syndesmosis intact

- ORIF if medial structures not intact

- xray below demonstrates Weber B with rupture deltoid ligament

- ankle unstable


Ankle Weber B Fracture


C.  Fracture above level syndesmosis

- syndesmosis at risk / must assume is torn

- medial structures often torn


Ankle Weber C Fracture


2.  Lauge-Hansen 1950


Two part 


1.  Position of talus

- supination tenses lateral structures

- pronation tenses medial structures


2.  Direction of force

- rotation or translational injury


A. Supination-Adduction

Stage 1: Transverse fracture of lateral malleolus at or below the level of anterior talo-fibular ligament (Weber B) 

Stage 2: Vertical fracture of medial malleolus (often a marginal impaction at medial edge of plafond)


Ankle Fracture Supination Adduction


B.  Supination-External Rotation (Most common - up to 85% all injuries)

Stage 1: Rupture of AITFL

Stage 2: Short oblique fracture of the lateral malleolus (Weber B) (stable)

Stage 3: Rupture of PITFL / fracture of posterior malleolus of tibia

Stage 4: Transverse fracture of medial malleolus (unstable) 


Ankle Fracture Supination ER


C. Pronation-Abduction (Less than 5% of ankle fractures)

Stage 1: Rupture of the deltoid ligament or transverse fracture of the medial malleolus

Stage 2: Rupture of the anterior and posterior inferior tibiotalofibular ligaments or bony avulsion

Stage 3: Proximal fibula fracture (often butterfly)


Ankle Pronation Abduction


D. Pronation-External Rotation

Stage 1: Rupture of the deltoid ligament or transverse fracture of the medial malleolus

Stage 2: Rupture of the anterior inferior tibiotalofibular ligaments or bony avulsion

Stage 3: Spiral/Oblique fracture of the fibula above the level of the syndesmosis        

Stage 4: Rupture of the posterior inferior tibiofibular ligament or fracture of the posterior malleolus


Ankle Fracture Pronation External Rotation


X-ray assessment


3 standard views


AP, lateral and mortise


Ankle AP XrayAnkle Mortise View





- foot internally rotated

- AP projection

- should be symmetrical clear space around talus


Ankle Mortise View


1.  Lateral talar shift / increased medial clear space

- medial clear space > superior clear space

- should be < 4mm

- indicates injury to medial structures

- instability


Ankle Fracture Increased Medial Clear SpaceAnkle Fracture Increased Medial Clear Space 2


2.  Tibia / fibular overlap < 1mm / syndesmotic injury


Ankle Fracture Syndesmosis WidenedAnkle Diastasis




Unimalleolar 70%

Bimalleolar 25%

Trimalleolar 7%

Open 2%







- protects skin medially

- conscious sedation in emergency department

- well moulded POP

- unstable ankles need monitoring for loss of reduction

- can need external fixation to maintain position


Ankle Fracture Severely Dislocated Dislocated Ankle Lateral



- operate when swelling reduced

- usually < 6 hours or 6 days

- higher risk with bimalleolar / 2 incision operations

- risk not being able to close wounds / infection


Long term results rely on

- reduction of talus under tibia

- mechanical stability

- degree of chondral damage


Medial ligament injury is the key to management


1.  Isolated Lateral Malleolar / Weber B Fracture


Ankle Fracture Isolated Weber BIsolated Fibula Fracture 3 mm displaced



- no medial fracture / no complete deep deltoid injury

- no increased medial clear space

- no instability on stress ER views

- no syndesmotic injury




85% have no medial injury

- by definition have no talar shift 


LM displacement not important if medial side not injured

- Biomechanical studies show Talus doesn't follow LM when axially loaded if medial ligament  intact 

- Doesn't lead to altered biomechanics


There is no external rotation of the distal fragment 

- its relationship to the talus is fixed

- the proximal fragment is internally rotated

- again, this does not alter the biomechanics


Diagnostic Dilemma / Is the deltoid ligament intact?




A.  Non tender / no bruising

- is intact

- non operative management


B.  Tender / bruising

- may be partially injury sprained / or completely ruptured and unstable

- inconclusive


Lateral BruisingMedial bruising




1.  Mortise view

- any increased clear space



2.  Stress views


Option A:  Gravity Stress View

- Patient lies injured side down, cross table xray

- see if medial clear space opens


Option B:  Valgus view

- lead gloves

- can be painful as patient has acute injury


Option C:  EUA


Results of Isolated Weber B Fibular Fracture


Results of surgical and non surgical management equally good

- Talus is stable if medial ligament is intact

- If  < 3mm fibula displacement, nil poor outcome


Non operative

- Kristensen and Hansen etal

- 95% good outcome non operatively

- no salvage operations required for post-traumatic arthritis



- 1-3% chance of serious infection

- more long term swelling




Cast in Internal Rotation to reduce the deformity


2.  Bi Malleolar Injury




A.  Medial Malleolus and Lateral Malleolus Fractured


Ankle Fracture Bimalleolar


B.  Deltoid tear + Lateral Malleolus Fractured


Ankle Fracture Weber B + Deltoid Ligament


If have talar shift, then by definition bi-malleolar injury

- must be an interruption to medial structures




Superior results with operative management

- able to obtain and maintain anatomical reduction

- 90% good results


Closed treatment

- for elderly or medically unfit

- acceptable reduction / ankle internally rotated

- 60% good results




1.  Weber B + Medial Malleolus fracture



- interfragmentary lag screw

- derotation 1/3 tubular plate


Medial malleolus (dependant on fragment size)

- 2 partially threaded lag screws

- 1 screw and one k wire



Screen syndesmosis

- should be stable with Weber B

- stress view (ER and dorsiflexion)

- cotton test (clamp on fibula and attempt to open syndesmosis under II)


Ankle Fracture Bimalleolar ORIFAnkle Fracture Bimalleolar ORIF


2.  Weber B + Deltoid Ligament


Ankle Weber B Deltoid Ligament InjuryAnkle Weber B Deltoid Ligament ORIF


A.  Manage Fibula as above

- ensure joint fully reduced


Ankle Fracture Fibula ORIF Increased Medial Clear Space


B.  Medial clear space remains open

- ensure fibular out to length and anatomical

- assess syndesmosis intact / reduce and fix

- if remains open, must be suspicious of OCD fragment or deltoid ligament blocking medial reduction

- may need to open medially


No evidence that repair of medial ligament improves results


3.  Tri-Malleolar Fracture


Posterior malleolus



- avulsion of PITFL


Ankle Fracture Small Posterior Malleolus Xray


Ankle instability results if

- > 1/3 articular surface (>30%)

- displacement of > 2mm 

- risk posterior subluxation of the tibio-talar joint



- these can be highly unstable and require external fixation


Trimalleolar UnstableTrimalleolar Unstable


Ankle External Fixator APAnkle External Fixator Lateral


Indications to ORIF posterior malleolus

- usually get anatomical reduction after plating of LM

- ORIF if > 30% and > 2mm displaced


 Ankle Fracture Large Posterior Malleolus XrayAnkle Fracture Large Posterior Malleolus CT


Surgical Options


1.  Posterolateral approach to fibula

- enable AP clamp to reduce and hold fracture

- anterolateral approach

- front to back screws


2.  Formal posterolateral approach

- patient lateral or prone

- PA screws or buttress plate


Posterior Malleolus LargePosterior tibial buttress plate


Ankle Fracture Trimalleolar ORIFAnkle Fracture Trimalleolar ORIF Lateral


4.  Syndesmosis Injury


Ankle Fracture Clear Syndesmotic Injury




Disruption of syndesmosis between level of fracture and plafond

- distal tibia and fibular not connected and stable




A.  Weber C fracture

- extremely high risk

- almost always safer to ORIF


Ankle Weber C Syndesmotic InjuryAnkle Weber C Syndesmotic Screw


B.  Weber B fracture + medial column injury

- occasionally syndesmotic injury

- check intraoperatively


C.  Maisonnerve injury

- high fibula fracture

- medial clear space opening / deltoid injury

- need diastasis screw


Ankle Fracture Maisonnerve InjuryAnkle Fracture Maisonnerve Proximal Fibula


D.  Isolated Injury


Ankle DiastasisORIF Diastasis


Intraoperative tests


Cotton test

Stress test




Reduction technique

- foot in neutral, clamp across medial and lateral malleolus

- don't reduce in plantarflexion as posterior talus is more narrow

- don't over reduce the joint

- check symmetrical joint space on mortise view


Diastasis Screw Fixation technique


1.  With other LM / MM fracture

- 1 or 2 screws

- 3 or 4 cortices

- 3.5 or 4.5 mm

- at level of epiphyseal scar


Ankle Fracture Diastasis Screw


2.  High Weber C fibula / Maisonnerve

- don't have to plate fibula

- ensure fibula out to length

- usually 2 screws

Post op


Need screw in for 8 - 10 weeks

- need to await ligament healing


- usually remove screw as will break


Ankle Broken Diastasis Screws


5.  Medial Malleolar Fractures


Medial Malleolus Fracture






- 20% risk of non union



- can usually manage in cast

- still small risk of non union




AO posteromedial approach ankle




A.  Large fragment

- 2 x screws


Ankle Fracture Medial Malleolus 2 Screws


B.  Small fragment

- screw + K wire



Ankle Fracture Medial Malleolus TBW


C.  Plate

- vertical fractures


Medial Malleolus Plate


6.  Open Ankle Fractures




Compound Ankle FractureMedial compound wounds


Clean & Closeable wound

- wound usually medial

- washout / ORIF / close


Dirty wound / wounds need skin cover

- external fixation

- wound management

- ORIF later


7.  DM



- amputation (6% open, 40% closed)

- infection

- malunion / non union / delayed union


Increased in patient with neuropathy and PVD



- increase fixation

- double NWB times

- leave sutures in for twice as long


8.  Elderly / Osteoporotic



- bone very poor

- good fixation difficult


Ankle Fracture OsteoporoticAnkle Osteoporotic Fixation





- uncommon

- Improve for up to 9 yrs


Medial Malleolus Non union



- worse after ORIF 

- continues > 3/12


Fibula malunion 

- decreases tibiotalar contact by 30%

- correction <4 years = Good results


Infection 1-4%


Missed fractures

- plafond fractures

- chondral lesions (50%)

- anterior process calcaneum








Ankle OA Post ORIF