High Yield Overview

ANKLE DISLOCATIONS

Talus Tibia Fibula | Urgent Reduction | Associated Fractures

RareLess than 1% of ankle injuries

UrgentReduce within hours

FracturesUsually associated

ORIFIf fractures present

DISLOCATION PATTERNS

Posterior

PatternMost common, talus posterior

TreatmentClosed reduction

PatternRare, talus anterior

TreatmentClosed reduction

Lateral

PatternRare, talus lateral

TreatmentClosed reduction

Medial

PatternRare, talus medial

TreatmentClosed reduction

Critical Must-Knows

Ankle dislocations = talus displaced from mortise (tibia-fibula) - usually associated with fractures, urgent reduction required
Posterior most common - Talus displaced posteriorly, usually with posterior malleolus fracture
Urgent reduction required - Skin tension causes necrosis, neurovascular compromise, reduce within hours
Usually associated fractures - Ankle fractures (malleoli), talus fractures, or both
ORIF if fractures present - After reduction, address associated fractures with ORIF

Examiner's Pearls

"
Posterior most common, usually with fractures
"
Urgent reduction required
"
Usually associated fractures
"
ORIF if fractures present

Clinical Imaging

Imaging Gallery

Lateral ankle radiograph showing gross unreduced ankle dislocation with severe posterior talar displacement.Credit: PMC Open Access via Open-i (NIH) (CC-BY 4.0)

Lateral ankle radiograph demonstrating posteromedial ankle dislocation pattern with posterior talar displacement.Credit: PMC Open Access via Open-i (NIH) (CC-BY 4.0)

Serial axial CT images (6 slices) demonstrating subtalar dislocation anatomy for post-reduction assessment.Credit: PMC Open Access via Open-i (NIH) (CC-BY 4.0)

Lateral ankle radiograph showing external fixator application following reduction of talar dislocation-fracture.Credit: PMC Open Access via Open-i (NIH) (CC-BY 4.0)

Lateral ankle radiograph showing gross unreduced ankle dislocation — Lateral ankle radiograph demonstrating unreduced ankle dislocation with obvious posterior displacement of the talus relative to the tibial plafond. Note the severe deformity requiring urgent closed reduction to relieve skin tension and prevent neurovascular compromise.Credit: PMC - CC BY 4.0

Critical Ankle Dislocation Exam Points

Urgent Reduction

Urgent reduction required - Skin tension causes necrosis within hours, neurovascular compromise. Reduce within hours, do not delay for imaging. Document neurovascular status before and after reduction.

Usually Associated Fractures

Ankle dislocations usually associated with fractures - Malleolar fractures, talus fractures, or both. After reduction, assess fractures and perform ORIF if indicated. CT scan after reduction to assess fractures.

Posterior Most Common

Posterior dislocation most common - Talus displaced posteriorly, usually with posterior malleolus fracture. Reduction: traction, plantarflex, then dorsiflex. Success rate 80-85%.

ORIF After Reduction

ORIF if fractures present - After reduction, address associated fractures with ORIF. Malleolar fractures require ORIF if displaced. Talus fractures require ORIF if displaced. Success rate 75-85%."

Ankle Dislocations - Quick Decision Guide

Type	Frequency	Treatment	Outcome
Posterior	Most common, usually with fractures	Closed reduction, ORIF	75-85% good results
Anterior	Rare, usually with fractures	Closed reduction, ORIF	75-85% good results
Lateral	Rare, usually with fractures	Closed reduction, ORIF	70-80% good results
Medial	Rare, usually with fractures	Closed reduction, ORIF	70-80% good results

Mnemonic

ANKLEAnkle Dislocation Features

Ankle

Talus from mortise

Neurovascular

Check before reduction

Knee

Flex knee for reduction

Lateral

Lateral rare

Emergency

Urgent reduction

Memory Hook:ANKLE: Ankle dislocation, Neurovascular check, Knee flexed, Lateral rare, Emergency reduction!

Mnemonic

REDUCEReduction Technique

Reduction

Urgent reduction

Emergency

Within hours

Document

Neurovascular status

Urgent

Do not delay

After reduction

Examine

Fractures

Memory Hook:REDUCE: Reduction urgent, Emergency within hours, Document neurovascular, Urgent do not delay, CT after reduction, Examine fractures!

Mnemonic

FRACTUREAssociated Fractures

Fractures

Usually associated

Reduction

Reduce first

Assess

Assess fractures

CT after reduction

Treatment

ORIF if needed

Urgent

Urgent reduction

Reduction

Reduce first

Examine

Examine fractures

Memory Hook:FRACTURE: Fractures usually associated, Reduction first, Assess fractures, CT after reduction, Treatment ORIF if needed, Urgent reduction, Reduction first, Examine fractures!

Overview and Epidemiology

Ankle dislocations are rare but serious injuries where the talus is displaced from the mortise (tibia-fibula). These dislocations are usually associated with fractures and require urgent reduction.

Definition

Ankle dislocation: Displacement of talus from mortise (tibia-fibula), which:

Location: Tibiotalar joint
Mechanism: High-energy trauma
Treatment: Urgent reduction, then ORIF if fractures
Outcome: Good with proper treatment

Types:

Posterior: Most common, talus posterior
Anterior: Rare, talus anterior
Lateral: Rare, talus lateral
Medial: Rare, talus medial

Epidemiology

Incidence: Less than 1% of ankle injuries
Age: Peak 20-40 years (trauma population)
Gender: No clear predominance
Mechanism: High-energy trauma (MVA, falls)
Associated injuries: Ankle fractures (malleoli), talus fractures

Urgent Reduction

Anatomy and Pathophysiology

Ankle Anatomy

Mortise:

Tibia: Medial malleolus, plafond
Fibula: Lateral malleolus
Talus: Fits in mortise
Ligaments: Deltoid, lateral ligaments, syndesmosis

Neurovascular structures:

Posterior tibial artery: Behind medial malleolus
Tibial nerve: With artery
Anterior tibial artery: Anterior
Deep peroneal nerve: With artery

Pathophysiology

Injury mechanism:

High-energy trauma: MVA, falls from height
Forces: Axial loading, rotation, translation
Fractures: Usually associated (malleoli, talus)

Why urgent reduction:

Skin tension: Causes necrosis within hours
Neurovascular compromise: Risk of ischemia
Soft tissue damage: Progressive with time

Why fractures usually associated:

High-energy mechanism: Causes fractures
Instability: Fractures contribute to instability
ORIF required: After reduction, address fractures

Classification Systems

Direction-Based Classification

Lateral ankle radiograph showing posteromedial ankle dislocation — Lateral ankle radiograph demonstrating posteromedial ankle dislocation with posterior displacement of the talus. This is the most common direction of pure ankle dislocation, typically resulting from forced dorsiflexion with external rotation.Credit: PMC - CC BY 4.0

Posterior:

Most common
Talus posterior
Usually with posterior malleolus fracture
Treatment: Closed reduction, ORIF

Anterior:

Rare
Talus anterior
Usually with anterior malleolus fracture
Treatment: Closed reduction, ORIF

Lateral:

Rare
Talus lateral
Usually with lateral malleolus fracture
Treatment: Closed reduction, ORIF

Medial:

Rare
Talus medial
Usually with medial malleolus fracture
Treatment: Closed reduction, ORIF

Direction guides reduction technique.

Clinical Assessment

History

Symptoms:

Ankle pain: Severe pain
Deformity: Obvious deformity
Inability to weight bear: Cannot bear weight
Mechanism: High-energy trauma

Risk factors:

High-energy trauma
MVA, falls from height
Sports injuries

Physical Examination

Inspection:

Obvious deformity
Swelling
Skin tenting (urgent reduction)
Open wound (if open)

Palpation:

Tenderness over ankle
Crepitus (if fractures)
Deformity

Neurovascular:

Document before reduction: Critical
Pulses: Dorsalis pedis, posterior tibial
Sensation: Dorsal and plantar foot
Motor: Ankle dorsiflexion, plantarflexion

Range of Motion:

Ankle ROM limited and painful
Cannot test due to pain

Clinical Examination Key Point

Document neurovascular status before reduction - Critical for medicolegal and clinical reasons. Check pulses (dorsalis pedis, posterior tibial), sensation (dorsal and plantar foot), and motor function (ankle dorsiflexion, plantarflexion). Repeat after reduction.

Investigations

Standard X-ray Protocol

AP view:

Shows dislocation
Assess mortise
Check for fractures

Lateral view:

Shows dislocation direction
Assess talus position
Check for fractures

Mortise view:

Shows mortise alignment
Assess syndesmosis
Check for fractures

Key point: Do not delay reduction for imaging if skin compromised.

Management Algorithm

Management Pathway

Ankle Dislocation Management

DiagnosisUrgent Assessment

Diagnose ankle dislocation clinically and radiographically. Document neurovascular status before reduction. Do not delay reduction for imaging if skin compromised. Urgent reduction required within hours.

ReductionClosed Reduction

Closed reduction under sedation or general anesthesia - Flex knee to relax gastrocnemius, traction, then reverse deformity (posterior: plantarflex then dorsiflex, anterior: dorsiflex then plantarflex). Document neurovascular status after reduction. Success rate 80-85%.

AssessmentCT After Reduction

CT scan after reduction to assess associated fractures - 80-90% have associated fractures (malleoli, talus, or both). Assess displacement and plan ORIF if indicated.

ORIFIf Fractures Present

ORIF if fractures present and displaced - Malleolar fractures require ORIF if displaced. Talus fractures require ORIF if displaced. Restore mortise stability. Success rate 75-85%.

Surgical Technique

Anterolateral Approach

Indication: Exposure of lateral malleolus, talus neck, and anterolateral joint.

Incision: Longitudinal over the fibula, curving anteriorly.
Internervous Plane: Between superficial peroneal nerve and sural nerve (distally).
Structures at Risk: Superficial peroneal nerve, intermediate dorsal cutaneous nerve.

Posterolateral Approach

Indication: Fixation of posterior malleolus and syndesmotic stabilization.

Incision: Midway between Achilles tendon and posterior border of fibula.
Internervous Plane: Between peroneus brevis (S1/L5) and flexor hallucis longus (S1/L2).
Structures at Risk: Sural nerve, small saphenous vein.

Complications

Complication	Incidence	Risk Factors	Prevention/Management
Post-traumatic arthritis	30-40%	Displacement, inadequate reduction	Anatomic reduction, adequate fixation
AVN talus	10-15%	Talus fractures, delayed reduction	Early reduction, anatomic fixation
Stiffness	20-30%	Prolonged immobilization	Early motion, adequate fixation
Nonunion	5-10%	Displacement, inadequate fixation	Rigid fixation

Post-Traumatic Arthritis

30-40% incidence:

Cause: Displacement, inadequate reduction, joint damage
Prevention: Anatomic reduction, adequate fixation
Management: Ankle fusion or arthroplasty if severe

AVN Talus

10-15% incidence (if talus fractures):

Cause: Talus fractures, delayed reduction, tenuous blood supply
Prevention: Early reduction, anatomic fixation
Management: Monitor with serial imaging, fusion if collapse

Postoperative Care

Clinical photo showing normal foot position after successful ankle dislocation reduction — Clinical photograph demonstrating normal foot and ankle alignment following successful closed reduction of an ankle dislocation. Restoration of normal limb axis confirms adequate reduction and is essential to prevent skin necrosis from persistent deformity.Credit: PMC - CC BY 4.0

Immediate Postoperative

Immobilisation: Short leg cast or boot
Weight bearing: Non-weight bearing (6-8 weeks)
ROM: Ankle ROM after cast removal
PT: Ankle ROM and strengthening

Rehabilitation Protocol

Weeks 0-6:

Short leg cast, non-weight bearing
Elevation to reduce swelling
Ankle ROM exercises (if stable)

Weeks 6-8:

CT to confirm healing
Cast removal if healing
Transition to walking boot
Progressive weight bearing

Weeks 8-12:

Full weight bearing
Progressive activity
Return to sport (3-4 months)

Outcomes and Prognosis

Overall Outcomes

Closed reduction (pure dislocation):

Success rate: 80-85% (stability, pain relief)
Functional outcomes: 75-80% return to pre-injury level
Arthritis: 20-30% develop arthritis

ORIF (with fractures):

Success rate: 75-85% (union, pain relief)
Functional outcomes: 70-75% return to pre-injury level
Arthritis: 30-40% develop arthritis

Open injuries:

Success rate: 60-70% (union, pain relief)
Functional outcomes: 60-70% return to pre-injury level
Arthritis: 40-50% develop arthritis

Long-Term Prognosis

Arthritis progression:

With proper treatment: 30-40% develop arthritis
Without treatment: 50-60% develop arthritis
Risk factors: Displacement, inadequate reduction, open injury

Evidence Base

Outcomes and Complications of Ankle Fracture-Dislocations

Level III

Warner SJ, et al. • Journal of Orthopaedic Trauma (2022)

Key Findings:

Dislocation is an independent risk factor for post-traumatic arthritis (OR 2.4)
Higher incidence of chondral damage compared to simple fractures
Functional outcomes (FAAM scores) significantly lower at 2 years
Articulation malreduction more common in fracture-dislocations

Clinical Implication: Counsel patients that dislocation portends a more guarded long-term prognosis than fracture alone.

Epidemiology and Patterns of Ankle Dislocation

Level IV

Tantigate D, et al. • Foot & Ankle International (2020)

Key Findings:

Lateral/Posterolateral dislocation most common (50-60%)
SER-IV is the dominant Lauge-Hansen pattern
85% associated with at least two malleolar fractures
Soft tissue interposition can obstruct closed reduction

Clinical Implication: Recognize that posterolateral dislocation often involves high-grade syndesmotic instability.

Exam Viva Scenarios

Practice these scenarios to excel in your viva examination

VIVA SCENARIOStandard

Scenario 1: Posterior Ankle Dislocation

EXAMINER

"A 35-year-old patient presents with ankle deformity after high-energy trauma. X-rays show posterior ankle dislocation with associated posterior malleolus fracture. Skin is tented but intact."

EXCEPTIONAL ANSWER

This is a posterior ankle dislocation with associated posterior malleolus fracture in a 35-year-old patient. I would take a systematic approach: First, confirm the diagnosis: Posterior ankle dislocation (most common type), talus displaced posteriorly, associated posterior malleolus fracture, skin tented but intact (urgent reduction required). Document neurovascular status before reduction - check pulses (dorsalis pedis, posterior tibial), sensation (dorsal and plantar foot), and motor function (ankle dorsiflexion, plantarflexion). Second, urgent reduction: This is an urgent reduction - skin tension causes necrosis within hours, neurovascular compromise. Do not delay for imaging if skin compromised. Reduction technique: Procedural sedation or general anesthesia, flex knee to relax gastrocnemius, apply traction, then reverse deformity (posterior: plantarflex then dorsiflex), feel clunk with successful reduction, confirm reduction with radiographs, repeat neurovascular examination after reduction. Third, post-reduction assessment: CT scan after reduction to assess associated fractures (posterior malleolus fracture displacement, other fractures), plan ORIF if fractures displaced. Fourth, ORIF: If posterior malleolus fracture displaced (greater than 25% joint surface or greater than 2mm step-off), ORIF required - Posterior approach, expose fracture, reduce anatomically, fix with screws (3.5-4.5mm), verify reduction fluoroscopically. Postoperatively, I would use short leg cast with non-weight bearing for 6-8 weeks, then CT to confirm healing, then progressive weight bearing, and monitor with serial imaging. I would counsel about good outcomes (75-85% good results with ORIF) but potential complications (post-traumatic arthritis 30-40%, AVN talus 10-15% if talus fractures, stiffness 20-30%). The key point is that urgent reduction is required within hours, and associated fractures require ORIF if displaced.

KEY POINTS TO SCORE

Urgent reduction within hours

Document neurovascular status before and after

Posterior most common, usually with fractures

ORIF if fractures displaced (75-85% good results)

COMMON TRAPS

✗Delaying reduction for imaging - skin necrosis risk

✗Not documenting neurovascular status - medicolegal risk

✗Not assessing fractures after reduction - miss displacement

✗Not understanding urgent reduction requirement

LIKELY FOLLOW-UPS

"Why is urgent reduction required?"

"What are the reduction techniques?"

"When is ORIF indicated for associated fractures?"

VIVA SCENARIOChallenging

Scenario 2: Open Ankle Dislocation

EXAMINER

"A 40-year-old patient has an open ankle dislocation with exposed talus. The examiner asks you to explain your management approach."

EXCEPTIONAL ANSWER

I will explain my management approach for open ankle dislocation. Key principle: This is an orthopaedic emergency requiring urgent reduction, debridement, and stabilization. Management: First, initial assessment: Document neurovascular status (critical for medicolegal and clinical reasons), assess wound (size, contamination, exposed bone), obtain radiographs (AP, lateral, mortise views), do not delay reduction for imaging. Second, urgent reduction: Reduce dislocation urgently under sedation or general anesthesia - Flex knee to relax gastrocnemius, apply traction, reverse deformity based on direction, confirm reduction radiographically, repeat neurovascular examination. Third, wound management: Urgent debridement in operating room - Extend wound if needed for adequate debridement, remove all contaminated and devitalized tissue, copious irrigation (minimum 3L), assess bone and soft tissue viability, leave wound open or use negative pressure wound therapy, plan for delayed closure or coverage. Fourth, fracture assessment: CT scan after reduction to assess associated fractures (malleoli, talus), plan ORIF if fractures displaced. Fifth, stabilization: External fixation if unstable or soft tissue compromised, ORIF if fractures displaced and soft tissue allows, consider staged approach (external fixator first, then ORIF when soft tissue ready). Sixth, antibiotics: IV antibiotics (cefazolin + gentamicin or vancomycin + piperacillin-tazobactam), continue for 24-48 hours, adjust based on cultures. Seventh, follow-up: Serial debridements if needed, delayed closure or coverage when soft tissue ready, monitor for infection, assess healing. The key point is that open dislocations require urgent reduction, aggressive debridement, and staged management, with worse outcomes than closed injuries (60-70% good results vs 75-85%).

KEY POINTS TO SCORE

Urgent reduction and debridement

Document neurovascular status

Staged management (external fixator, then ORIF)

Worse outcomes than closed (60-70% good results)

COMMON TRAPS

✗Delaying reduction - skin necrosis and infection risk

✗Not debriding adequately - infection risk

✗Not using staged approach - soft tissue compromise

✗Not understanding worse outcomes

LIKELY FOLLOW-UPS

"Why are open injuries worse?"

"When would you use external fixation?"

"What are the infection rates?"

VIVA SCENARIOStandard

Scenario 3: Failed Closed Reduction

EXAMINER

"You are in the ED attempting to reduce a lateral ankle dislocation. Despite adequate sedation and correct technique, the talus will not 'clunk' back into the mortise. What are your next steps?"

EXCEPTIONAL ANSWER

This is a failed closed reduction of an ankle dislocation, which suggests soft tissue interposition. I would approach this systematically: First, reassess technique: Ensure the knee is fully flexed to relax the gastrocnemius-soleus complex. Re-attempt with a second person providing counter-traction. Second, identify causes of obstruction: Common structures that block reduction include the tibialis posterior tendon, flexor hallucis longus, or infolded deltoid ligament. In lateral dislocations, the medial structures are often responsible. Third, imaging: Obtain urgent AP and lateral radiographs to confirm the depth of the obstruction or identify any bony block (e.g., intra-articular fragment). Fourth, proceed to Open Reduction: If a second attempt fails, I would take the patient to the OR for emergent open reduction. I would use an approach tailored to the likely area of obstruction (e.g., medial approach for lateral dislocations). Once open, I would identify the entrapped structure, retract it, and gently reduce the talus. Fifth, definitive management: After open reduction, I would assess the stability and perform ORIF of any associated fractures as indicated. The key is never to force a reduction, as this can cause further chondral damage or neurovascular injury.

KEY POINTS TO SCORE

Soft tissue interposition prevents reduction

Structures: Tibialis posterior, FHL, Deltoid

Emergent open reduction in the OR

Never force a reduction

COMMON TRAPS

✗Repeatedly attempting closure - risk of NV injury/chondral scuffing

✗Waiting until the morning for the OR - skin necrosis risk

LIKELY FOLLOW-UPS

"Which tendon is most commonly entrapped in medial dislocations?"

"What is the 'dimple sign' in ankle dislocations?"

"How does the Lauge-Hansen classification help predict entrapped structures?"

MCQ Practice Points

Urgent Reduction

Q: Why is urgent reduction required for ankle dislocations? A: Skin tension causes necrosis within hours, neurovascular compromise - Reduce within hours, do not delay for imaging if skin compromised. Document neurovascular status before and after reduction.

Associated Fractures

Q: Are ankle dislocations usually associated with fractures? A: Yes, 80-90% have associated fractures - Malleolar fractures most common, talus fractures less common. After reduction, assess fractures with CT and perform ORIF if displaced.

Posterior Dislocation

Q: What is the most common type of ankle dislocation? A: Posterior dislocation is most common - Talus displaced posteriorly, usually with posterior malleolus fracture. Reduction: traction, plantarflex, then dorsiflex. Success rate 80-85%.

Treatment

Q: What is the treatment for ankle dislocations? A: Urgent closed reduction, then ORIF if fractures present - Reduce within hours, document neurovascular status, CT after reduction to assess fractures, ORIF if displaced. Success rate 75-85% with proper treatment.

Complications

Q: What are the complications of ankle dislocations? A: Post-traumatic arthritis (30-40%), AVN talus (10-15% if talus fractures), stiffness (20-30%) - Prevent with anatomic reduction and adequate fixation. Success rate 75-85% with proper treatment.

Australian Context

Clinical Practice

Ankle dislocations rare but serious
Urgent reduction required
Usually associated with fractures
ORIF if fractures present

Healthcare System

Procedures covered under public system
Public hospitals handle most cases
Private insurance covers procedures
High-energy trauma common

Orthopaedic Exam Relevance

Ankle dislocations are a common viva topic. Know that urgent reduction required (within hours, skin necrosis risk), usually associated with fractures (80-90%), posterior most common, ORIF if fractures displaced (75-85% good results), and document neurovascular status before and after reduction. Be prepared to discuss the reduction technique and management of associated fractures.