Background

 

Fracture patterns

 

Lateral malleolar fractures Medial malleolar fractures Bimalleolar fractures Trimalleolar fractures

Weber A - below syndesmosis

Weber B - at syndesmosis

Weber C - above syndesmosis

Uncommon

Fibular + medial malleolus

Bimalleolar equivalent - fibular + deltoid ligament

Fibular + posterior malleolus

Fibular fracture

Medial malleolus fracture

Posterior malleolus frac

Weber C Med Mall Bimall Trimall

 

Anatomy

 

Ligaments

 

Lateral Ligament Complex Deltoid ligament Sydesmosis

ATFL

CFL

PTFL

Superficial deltoid

Deep deltoid

AITFL

PITFL

Interosseous ligament

 

 

Biomechanics

 

Load ROM Dorsiflexion Plantarflexion

90% load through plafond to talus

10% load through lateral talofibular articulation

Dorsiflexion 30°

Plantarflexion 45°

Talus wider anteriorly 2.5 mm

Fibula moves laterally & ER to accommodate

 

 

Deltoid ligament prevents ER of talus

5° internal rotation talus

 

Ramsey et al JBJS Am 1976

- 1mm lateral talus shift

- ankle contact area decreased by 40%

 

Ankle Fracture Classification 

 

Weber Classification of fibular fractures

 

Weber A Weber B Weber c
Fracture distal to syndesmosis Fracture at level of syndesmosis Fracture above level syndesmosis

Stable - avulsion fracture

Stability depends on deltoid ligament

 

Stable - no increased medial clear space / deltoid ligament intact

Unstable - Increased medial clear space / deltoid ligament rupture

Unstable

 

Syndesmosis disrupted

Weber A Weber bweber b Weber C

 

Lauge-Hansen Classfication

 

Two part

1.  Position of talus - pronation / supination

2.  Direction of force - external rotation or translational (adduction / abduction)

 

Supination-Adduction Supination-External Rotation Pronation-Abduction Pronation-External Rotation

Stage 1: Weber B fibula

 

Stage 1: Rupture of AITFL

 

Stage 1: Deltoid ligament rupture / transverse fracture of the medial malleolus

 

Stage 1: Deltoid ligament rupture /  transverse fracture of the medial malleolus

      

Stage 2: Vertical medial malleolus Stage 2: Weber B fibular Stage 2: Rupture of the AITLF / PITFL or bony avulsion Stage 2: Rupture of the AITFL or bony avulsion
  Stage 3: Rupture of PITFL / fracture of posterior malleolus Stage 3: Weber C fibula (often butterfly) Stage 3: Spiral/Oblique fracture Weber C
  Stage 4: Transverse fracture of medial malleolus   Stage 4: Rupture of the PITFL or fracture of the posterior malleolus
  Most common - up to 85% all injuries Less than 5% of ankle fractures  
Ankle Fracture Supination Adduction Ankle Fracture Supination ER Ankle Pronation Abduction Ankle Fracture Pronation External Rotation

 

X-ray assessment

 

3 standard views

 

AP / Lateral / Mortise

 

Mortise

- AP with foot internally rotated

- should be symmetrical space around talus

 

Ankle Mortise ViewMortise

 

 Increased tibio-fibular Clear space  Overlap Increased medial clear space

Medial border of the fibula

Lateral border of the posterior tibia (incisura fibularis)

Measured 1 cm above the plafond

Overlap of the fibula and the anterior tibial tubercle

 

Medial talus to lateral medial malleolus

<5mm AP and mortise

> 6 mm AP view

> 1 mm mortise view

< 4mm

Equal to superior clear space

Syndesmotic injury Syndesmotic injury

Deltoid ligament injury

Lateral talar shift

Ankle AP Xray Syndesmotic Measurements Ankle Mortice Xray Syndesmotic Measurements Mortise

 

Lateral talar shift / increased medial clear space / deltoid ligament injury

 

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

 

Tibia / fibular overlap < 1mm / syndesmotic injury

 

Ankle Fracture Syndesmosis WidenedAnkle Diastasis

 

Management

 

Ankle dislocation

 

Reduction under conscious sedation

- protects skin medially

- conscious sedation in emergency department

- well moulded cast

- unstable ankles need monitoring for loss of reduction

- can need external fixation to maintain position

 

Dislocationdislocationdislocation

 

External fixation

 

trimallTrimallTrimallTrimall

 

Compound fractures

 

Compound ankleCompoundCompound

 

Compound Ankle FractureMedial compound wounds

 

Results

 

Martin et al J Orthop Trauma 2021

- 41 open ankle dislocations with medial wound

- pronation-abduction

- 10% deep infection, one amputation

 

Kahan et al Injury 2020

- 22 open pronation-abduction injuries compared with 35 other open ankle fractures

- pronation abduction group associated with obesity, reoperations, arthrodesis and ampution

 

Operative Management

 

Diabetes / elderly / fragility fractures

 

Issues

 

High risk infection / wound complications / loss of fixation

 

www.boneschool.com/fragility-fractures

 

Timing of surgery

 

Operate when swelling reduced / wrinkling / resolution of blisters

- risk not being able to close wounds / infection

- higher risk with bimalleolar / 2 incision operations

 

Schepers et al Int Orthop 2013

- prospective study of ankle fracture surgery

- infection rate surgery < 1 day: 0/60

- infection rate delayed surgery: 16/145 (11%)

- infection rate surgery < 1 week: 2%

- infection rate surgery > 1 week: 13%

 

Skin preparation

 

Sprague et al NEJM 2024

- RCT of iodine v chorhexidine prep

- 6700 patients undergoing ankle fracture surgery

- closed fracture infections: iodine 2.4%, chlorhexidine 3.3%

- open fracture infections: iodine 6.5%, chorhexidine 7.3%

 

Early Weight bearing

 

Sharma et al Foot Ankle Surg 2022

- early versus delayed weight bearing

- meta-analysis of 14 RCTs

- early weight bearing had better short term outcomes at 6 - 9 weeks

- no difference at 6 months

- early return to work with early weight bearing

 

Baumbach et al Foot Ankle Surg 2023

- early versus delayed weight bearing

- meta-analysis of 13 studies

- early weight bearing did not increase complication rate

 

Early ROM

 

Keene et al J Orthop Sports Phys Ther 2014

- meta-analysis of immobilization versus early ROM

- 11 studies

- no difference in functional outcomes at 6 weeks, 3 months or 1 year

- reduced DVT with early ROM

- increased infection / fixation failure / removal of metalwork with early ROM

 

Complications

 

Infection

 

Infection 2infection 1

 

Shao et al Int J Surg 2018

- systematic review of 10 studies and 8000 operative fixation ankle fractures

- incidence infection 7%

- increased with: open fractures / fracture dislocations / high energy injuries

- increased with: increased BMI, ASA 3, diabetes, smoking

 

DVT / PE

 

Blanco et al J Foot Ankle Surg 2018

- prospective cohort and 90 incidence of DVT / PE

- achilles tendon in cast: 5%

- ankle fracture cast / no surgery:2%

- ankle fracture surgery: 3%

 

Elliott et al Arch Orthop Trauma Surg 2023

- 483 patients with surgically treated ankle fractures

- DVT / PE no prophylaxis: 3.5%

- DVT / PE with prophylaxis: 4%

- no difference in complications

 

Osteoarthritis

 

Swierstra et al EFORT Open Rev 2022

- systematic review

- overall incidence of post-traumatic OA 25%

 

Beak et al Foot Ankle Int 2022

- risk factors for OA in 330 patients

- increased risk with fracture dislocations / posterior malleolar fractures / malreduction

 

Ankle OA Post ORIF