Acetabular Fracture

An acetabular fracture is an intra articular fracture of the hip socket involving one or more walls or columns.

Outcome is strongly related to:

Quality of articular reduction
Femoral head viability
Marginal impaction
Cartilage damage
Hip stability
Age
Bone quality

The acetabulum is conceptualised as an inverted Y, consisting of anterior and posterior columns.

Letournel and Judet classification

There are five elementary and five associated fracture patterns.

Elementary fractures

1. Posterior wall

The commonest acetabular fracture.

Frequently associated with posterior hip dislocation.

2. Posterior column

The posterior column is separated from the remaining acetabulum.

3. Anterior wall

Isolated anterior rim injury.

Relatively uncommon.

4. Anterior column

Fracture traverses the anterior column from iliac wing or pelvic brim into the obturator region.

5. Transverse

A fracture line crosses both columns while part of the acetabulum remains connected to the axial skeleton.

Associated fractures

1. Posterior column plus posterior wall

2. Transverse plus posterior wall

3. T shaped

Transverse fracture plus a vertical limb dividing the inferior acetabulum.

4. Anterior column plus posterior hemitransverse

5. Both column fracture

Both columns are detached from the axial skeleton.

The articular surface is effectively free from the intact posterior ilium.

The classic radiographic feature is a spur sign representing residual iliac attachment to the axial skeleton.

Most major fractures follow high energy trauma.

Older osteoporotic patients can sustain anterior column or quadrilateral surface injuries after lower energy falls.

Assess for associated hip dislocation.

Posterior wall fractures commonly accompany posterior dislocation and sciatic nerve injury.

Document sciatic nerve function:

Peroneal division

Ankle dorsiflexion
Toe extension
Dorsal foot sensation

Tibial division

Plantar flexion
Plantar sensation

Also evaluate femoral and obturator nerve function in relevant anterior injuries.

Obtain:

AP pelvis
Obturator oblique Judet view
Iliac oblique Judet view

CT pelvis: essential for operative planning.

CT defines:

Articular displacement
Posterior wall size
Marginal impaction
Intra articular fragments
Quadrilateral plate displacement
Femoral head fracture
Column morphology

Roof arc concept

Roof arc measurements assess whether the intact superior weight bearing dome remains adequate.

Approximately 45° or greater on AP and Judet views generally indicates sufficient intact superior dome for selected nonoperative management.

Roof arc measurements are less useful for posterior wall fractures and both column fractures.

Emergency hip dislocation

If the acetabular fracture is associated with hip dislocation, reduce the hip urgently.

Reduction should not wait for definitive acetabular fixation.

Nonoperative treatment

Appropriate when:

Displacement is below approximately 2 mm
Hip remains congruent
Weight bearing dome remains intact
Posterior wall fracture is dynamically stable
Patient cannot tolerate surgery

Protected weight bearing is generally maintained for approximately 6 to 8 weeks.

Early hip movement is encouraged.

Posterior wall stability

Fragment size alone is not sufficient.

A posterior wall fracture involving an intermediate portion of the wall may require examination under anaesthesia with fluoroscopic stress testing.

If the femoral head subluxates under stress, the fracture is unstable and requires fixation.

Operative indications

ORIF is generally indicated for:

More than approximately 2 mm articular displacement in the weight bearing region
Hip instability
Incarcerated intra articular fragment
Marginal impaction
Irreducible fracture dislocation
Progressive displacement
Selected both column fractures without secondary congruence

Displaced fractures require anatomical or near anatomical reconstruction to minimise post traumatic arthritis.

Surgical approaches

Kocher Langenbeck

Used for:

Posterior wall
Posterior column
Many transverse plus posterior wall injuries

Protect the sciatic nerve.

Ilioinguinal

Traditional anterior approach for anterior column and selected both column injuries.

Modified Stoppa or anterior intrapelvic approach

Provides excellent access to:

Quadrilateral surface
Medial acetabulum
Anterior column
Pelvic brim
Posterior hemitransverse component

Iliofemoral or extended approaches

Used selectively for complex patterns requiring broad exposure but carry greater soft tissue morbidity and heterotopic ossification risk.

Reduction sequence

The specific sequence depends on fracture pattern.

General principles are:

Reconstruct the column that provides the main reference
Restore pelvic brim
Restore quadrilateral surface
Correct articular fragments
Address marginal impaction
Confirm femoral head congruity

Marginally impacted osteochondral fragments must be elevated and supported rather than simply covered by a plate.

Both column fracture

Some both column fractures develop secondary congruence, where displaced acetabular fragments remain congruent around the femoral head.

Selected older low demand patients can therefore be treated nonoperatively despite displacement.

Young patients with substantial displacement generally require reconstruction.

Elderly acetabular fracture

Severe osteoporotic comminution, dome impaction, femoral head damage and marginal impaction predict fixation failure.

Options include:

ORIF
ORIF followed by delayed arthroplasty if arthritis develops
Acute fixation plus total hip arthroplasty in selected patients

Acute arthroplasty is particularly attractive when the joint surface is not realistically reconstructable.

Rehabilitation

Early hip range of motion is encouraged after stable reconstruction.

Weight bearing is usually restricted for approximately 8 to 12 weeks, depending on fracture pattern and fixation.

Major complications include:

Post traumatic osteoarthritis
Sciatic nerve injury
Heterotopic ossification
Infection
Osteonecrosis after associated hip dislocation
Loss of reduction
Intra articular screw penetration
DVT
Need for later total hip arthroplasty

Clinical toolsCalculators

BMI GCS EDD Parkland Formula

Corrected Sodium Corrected Calcium Anion Gap Creatinine Clearance Insulin Calculations qSOFA Wells PE Wells DVT CHA₂DS₂-VASc HAS-BLED CURB-65 Centor/McIsaac

Ankle Fracture

An ankle fracture can involve the lateral malleolus, medial malleolus, posterior malleolus or combinations of these structures with associated deltoid and syndesmotic ligament injury.

The treatment question is not simply whether a malleolus is fractured. The key question is:

Is the talus stable and anatomically centred within the ankle mortise?

Loss of even small degrees of talar alignment substantially alters ankle contact mechanics.

Danis Weber classification

Classifies the fibular fracture according to its relationship to the distal tibiofibular syndesmosis.

Weber A

Fibular fracture below the syndesmosis.

Usually stable if the medial structures are intact.

Often corresponds to supination adduction injury.

Weber B

Fibular fracture at the level of the syndesmosis.

Syndesmotic stability varies.

Commonly corresponds to supination external rotation.

Weber C

Fibular fracture above the syndesmosis.

Strongly associated with syndesmotic disruption and an unstable ankle.

A very proximal Weber C fracture associated with syndesmotic and medial injury is a Maisonneuve fracture.

Palpate the entire fibula in every apparently isolated medial ankle injury.

Lauge Hansen classification

Describes foot position followed by direction of deforming force.

Supination external rotation

Most common pattern.

Stage 1:

Anterior inferior tibiofibular ligament injury.

Stage 2:

Oblique spiral distal fibular fracture at the syndesmosis.

Stage 3:

Posterior inferior tibiofibular ligament rupture or posterior malleolar fracture.

Stage 4:

Medial malleolar fracture or deltoid ligament rupture.

Supination adduction

Stage 1:

Distal fibular avulsion or transverse infrasyndesmotic fracture.

Stage 2:

Vertical medial malleolar fracture, often with medial plafond impaction.

Pronation external rotation

Stage 1:

Medial malleolar fracture or deltoid disruption.

Stage 2:

Anterior syndesmotic injury.

Stage 3:

Spiral fibular fracture above the syndesmosis.

Stage 4:

Posterior syndesmotic injury or posterior malleolar fracture.

Pronation abduction

Stage 1:

Medial malleolar fracture or deltoid disruption.

Stage 2:

Syndesmotic injury.

Stage 3:

Transverse or comminuted suprasyndesmotic fibular fracture.

The mechanism classification is useful for understanding injury sequence, but it does not predict every ligament injury reliably.

Patients present with ankle pain, swelling and inability or difficulty bearing weight.

Inspect for:

Gross dislocation
Open wound
Skin tenting over the medial malleolus
Fracture blisters
Medial tenderness
Proximal fibular tenderness

Document:

Dorsalis pedis and posterior tibial pulse
Superficial peroneal sensation
Deep peroneal sensation
Tibial nerve sensation
Motor function where pain permits

An ankle fracture dislocation can rapidly threaten medial skin and requires immediate reduction.

Obtain:

AP
Mortise
Lateral ankle radiographs

The mortise view is obtained with approximately 15° internal rotation and allows assessment of talar centring.

Obtain full length tibia and fibula imaging when:

Proximal fibula is tender
Medial injury exists without obvious distal fibular fracture
Maisonneuve injury is possible

CT: obtain for:

Posterior malleolar fracture
Trimalleolar fracture
Pilon overlap
Complex articular injury
Preoperative planning where posterior fragment morphology changes approach

Stable versus unstable isolated Weber B fractures can be clarified with weight bearing radiographs once pain allows or selected stress imaging.

Medial clear space widening suggests deep deltoid incompetence and talar instability, but interpretation should consider mortise positioning and comparison with the superior clear space.

Emergency reduction

Immediately reduce:

Fracture dislocation
Threatened skin
Neurovascular compromise
Severe talar displacement

Use adequate analgesia or procedural sedation.

After reduction:

Repeat neurovascular examination
Obtain post reduction radiographs
Apply a well moulded splint

Do not leave the ankle in a redislocated position because the splint was inadequately moulded.

Stable fracture

Stable isolated lateral malleolar fractures with a congruent mortise can be managed nonoperatively using a walking boot or functional brace.

Early weight bearing as tolerated is increasingly appropriate in stable injuries.

Repeat imaging is required if stability was initially uncertain.

Unstable fracture

Operative fixation is appropriate for:

Bimalleolar fracture
Bimalleolar equivalent fracture with deltoid incompetence and talar shift
Trimalleolar fracture with instability
Talar displacement
Unstable syndesmotic injury
Displaced medial malleolar fracture causing mortise incongruity
Open fracture
Failure to maintain acceptable reduction

Lateral malleolus

Simple oblique fibular fractures can be treated with lag screw compression plus a neutralisation plate or with an antiglide construct.

Comminuted fibular fractures require restoration of:

Length
Rotation
Alignment

A bridging plate can preserve comminution biology.

Fibular shortening is unacceptable because it permits lateral talar shift.

Medial malleolus

Reduce the articular surface anatomically.

Common fixation uses:

Lag screws
Screw plus antiglide strategy for vertical patterns
Cerclage compression constructs for small fragments

A vertical medial malleolar fracture must be protected against vertical shear rather than treated as a simple transverse avulsion.

Posterior malleolus

The older rule of fixing only fragments involving more than 25% of the articular surface is no longer sufficient.

Fixation should be considered according to:

Articular displacement
Posterior fragment morphology
Involvement of the incisura
Syndesmotic instability
Persistent posterior talar subluxation
Size of the fragment

Direct posterior reduction is increasingly preferred for substantial displaced fragments because it restores both articular congruity and the posterior syndesmotic attachment.

Syndesmosis

After malleolar fixation, assess syndesmotic stability.

Fix an unstable syndesmosis only after the fibula has been restored to correct length and rotation.

Options include:

3.5 or 4.5 mm syndesmotic positioning screw
Flexible suture button construct

A positioning screw should stabilise rather than compress the distal tibiofibular relationship. AO technique places the screw just above the distal tibiofibular joint, parallel to the plafond, with the ankle neutral.

Malreduction of the syndesmosis is a major cause of poor outcome.

Deltoid ligament

Routine deltoid repair is unnecessary when fixation restores a congruent stable mortise.

Explore or repair when:

Medial tissue is interposed and blocks reduction
Persistent medial instability remains despite correct osseous and syndesmotic reconstruction.

Postoperative management

Begin ankle movement once wound condition and fixation stability permit.

Stable anatomically reconstructed fractures can often begin early protected weight bearing, although severe fractures, poor bone quality and syndesmotic constructs may require greater restriction.

Major complications include:

Wound problems
Infection
Syndesmotic malreduction
Fibular shortening
Ankle stiffness
Post traumatic osteoarthritis
Symptomatic hardware
Nonunion, particularly medial malleolus
Chronic instability

Acetabular Fracture

Overview

Clinical Features

Diagnosis

Management

Overview

Clinical Features

Diagnosis

Management