Hip Dislocation

Traumatic hip dislocation is displacement of the femoral head from the acetabulum and is usually a high energy injury.

Because the native hip is intrinsically very stable, dislocation implies substantial soft tissue disruption and frequently associated fracture.

This is an orthopaedic emergency.

The femoral head should be reduced as rapidly as possible, ideally within approximately 6 hours, because delayed reduction increases the risk of osteonecrosis and post traumatic arthritis.

Direction classification

Posterior dislocation

Approximately 85% to 90% of traumatic dislocations.

Mechanism:

Axial force through a flexed, adducted hip, classically a dashboard injury.

Position:

Hip flexed
Adducted
Internally rotated

Sciatic nerve is at risk.

Anterior dislocation

Less common.

Occurs with forced abduction and external rotation.

Can be:

Superior, pubic type
Inferior, obturator type

The limb is generally abducted and externally rotated.

Simple versus complex

Simple

Dislocation without associated fracture.

Complex

Dislocation with:

Thompson Epstein classification of posterior fracture dislocation

Type I

Simple posterior dislocation with no fracture or only a minor posterior wall fragment.

Type II

Dislocation with a single large posterior acetabular wall fragment.

Type III

Dislocation with a comminuted posterior wall fracture.

Type IV

Dislocation with acetabular floor fracture.

Type V

Dislocation with femoral head fracture.

Pipkin classification

Used for femoral head fracture associated with hip dislocation.

Pipkin I

Femoral head fracture inferior to the fovea capitis.

The fragment is outside the main superior weight bearing surface.

Pipkin II

Femoral head fracture superior to the fovea.

Involves weight bearing articular surface.

Pipkin III

Type I or II femoral head fracture plus femoral neck fracture.

Carries very high risk of osteonecrosis.

Pipkin IV

Type I or II femoral head fracture plus acetabular fracture, usually posterior wall.

Posterior dislocation typically produces a shortened, flexed, adducted and internally rotated limb.

Anterior dislocation usually produces abduction and external rotation.

Do not assume an abnormal limb position is simply a dislocation. Associated femoral neck or acetabular fracture may alter the posture.

Document sciatic nerve function before reduction.

Particularly assess the peroneal division:

Ankle dorsiflexion
Great toe extension
Dorsal foot sensation

Also assess distal pulses.

The sciatic nerve is injured in a significant minority of posterior fracture dislocations.

Obtain an AP pelvis rapidly if this does not meaningfully delay reduction.

A clearly dislocated hip in a stable trauma patient should be reduced urgently.

If femoral neck fracture is suspected, excessive closed manipulation can worsen the injury and operative reduction may be necessary.

Post reduction CT should be performed after traumatic hip dislocation to identify:

Femoral head fracture
Acetabular fracture
Intra articular loose bodies
Incongruent reduction.

Immediate reduction

Provide procedural sedation or general anaesthesia with adequate muscle relaxation.

Perform controlled closed reduction.

Common posterior reduction techniques include:

Allis
Stimson
Captain Morgan

The specific manoeuvre is less important than controlled axial traction with avoidance of excessive force.

After reduction:

Repeat sciatic nerve examination
Repeat vascular examination
Confirm concentric reduction radiographically
Obtain CT

Open reduction indications

Proceed to open reduction when:

Closed reduction fails
Dislocation is irreducible
Femoral head or acetabular fragment blocks reduction
Reduction remains nonconcentric
Associated femoral neck fracture makes closed manipulation unsafe

Simple dislocation

After concentric reduction without fracture:

Begin early controlled hip motion
Protected weight bearing initially
Avoid extreme flexion and adduction after posterior injury during early healing

Prolonged traction is not routinely required.

Pipkin I

A small non weight bearing femoral head fragment can sometimes be excised when it remains displaced or loose.

Larger reconstructable fragments should be fixed.

Pipkin II

Because the fracture involves the weight bearing femoral head, aim for anatomical reduction and internal fixation.

Pipkin III

Young patients require urgent anatomical femoral neck and head reconstruction when feasible.

In older patients, arthroplasty may provide more reliable treatment because the combined neck and head injury has a very high osteonecrosis and fixation failure risk.

Pipkin IV

Treat both:

Femoral head injury
Acetabular fracture

Posterior wall stability frequently determines whether acetabular fixation is required.

Osteonecrosis

Reduction timing is critical but does not eliminate the risk entirely.

Follow patients clinically and radiographically.

Persistent or progressive hip pain months after injury should trigger investigation for:

Osteonecrosis
Post traumatic arthritis
Loose body
Heterotopic ossification

Major complications include:

Osteonecrosis
Sciatic nerve palsy
Post traumatic osteoarthritis
Heterotopic ossification
Recurrent instability, uncommon after simple traumatic dislocation
Femoral head chondral injury

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

Pilon Fracture

A pilon fracture is a fracture of the distal tibial plafond caused by axial compression of the talus into the distal tibial articular surface.

The injury can involve:

Severe articular impaction
Metaphyseal comminution
Fibular fracture
Major swelling
Fracture blisters
Open injury

The word pilon refers specifically to the weight bearing distal tibial articular surface, not every distal tibial fracture.

High energy pilon fracture management is dominated by the soft tissue envelope.

Attempting definitive plate fixation through severely swollen tissues dramatically increases wound necrosis and infection.

Rüedi and Allgöwer classification

Type I

Nondisplaced articular fracture.

Type II

Displaced articular fracture without major comminution.

Type III

Severely comminuted and impacted articular fracture.

The system is simple but does not fully represent modern CT based fracture anatomy.

AO/OTA classification

Distal tibia is coded 43.

43A: Extraarticular

The plafond is intact.

43B: Partial articular

Part of the plafond remains attached to the tibial shaft.

43C: Complete articular

The entire articular surface is separated from the shaft.

C1 simple articular, simple metaphyseal
C2 simple articular, multifragmentary metaphyseal
C3 multifragmentary articular and metaphyseal

Increasing comminution substantially increases reconstructive difficulty.

High energy injuries usually follow:

Fall from height
Motor vehicle collision
Major axial load

Patients present with severe ankle pain, deformity and rapidly developing swelling.

Inspect for:

Open wounds
Fracture blisters
Skin tenting
Medial skin compromise
Heel and hindfoot injuries
Compartment syndrome

Document tibial and peroneal nerve function and distal perfusion.

A displaced fragment threatening the skin requires immediate reduction, not observation while swelling progresses.

Obtain AP, lateral and mortise ankle radiographs.

Include the tibial shaft where proximal extension is possible.

CT: essential for displaced articular pilon fractures.

For severe high energy fractures requiring temporary spanning external fixation, perform definitive CT after provisional reduction and external fixation whenever possible. This demonstrates the reconstructable fragment anatomy in near anatomical spatial relationships.

Important CT information includes:

Anterolateral fragment
Anteromedial fragment
Posterolateral fragment
Posteromedial fragment
Central impacted fragments
Chaput fragment
Volkmann fragment
Fibular morphology

Immediate priorities

Urgently reduce gross ankle deformity.

Apply a well padded splint.

Elevate the limb.

Treat open fracture according to open fracture principles.

Severe swelling usually precludes immediate definitive fixation.

Nonoperative treatment

Reserved for:

Truly nondisplaced stable fractures
Patients with prohibitive operative risk
Selected very low demand patients

Use cast or brace immobilisation with strict surveillance.

Displaced articular pilon fractures generally have poor results with closed treatment alone.

Staged treatment

The standard strategy for most high energy injuries is:

Stage 1

Restore gross length and alignment
Apply ankle spanning external fixation
Treat associated open wounds
Perform urgent debridement when open
Stabilise the fibula selectively where this assists reconstruction and does not compromise future approaches

Stage 2

Allow soft tissues to recover.

Definitive reconstruction is performed after:

Marked swelling has subsided
Fracture blisters have epithelialised or resolved appropriately
Skin wrinkles have returned

This commonly takes approximately 7 to 14 days, but soft tissue condition rather than the calendar determines timing. Staged treatment is used for the majority of major high energy pilon fractures.

Definitive reconstruction

Classical principles are:

Restore fibular length when required
Reconstruct the tibial articular surface
Fill clinically significant metaphyseal defects where structural support is required
Restore tibial length and alignment
Stabilise the metaphysis using plates with minimal additional soft tissue injury

Approach selection is determined by CT fragment anatomy.

Common approaches include:

Anterolateral
Anteromedial
Posterolateral
Posteromedial

Do not create narrow skin bridges between large incisions.

Articular reconstruction

Reduce major articular fragments anatomically.

Restore the relationship between:

Medial malleolus
Chaput fragment
Posterior Volkmann fragment
Central plafond

Articular impaction must be elevated before the metaphysis is fixed.

Subchondral defects can require cancellous graft or structural substitute.

Fibular fracture

Fibular fixation can:

Restore length
Assist reduction of the lateral plafond
Improve ankle mortise alignment

But fixing the fibula during the initial stage is not obligatory in every case. It should fit the definitive reduction strategy and planned surgical approaches.

External fixation as definitive treatment

Circular or hybrid fixation may be useful when:

Soft tissue injury makes extensive ORIF unsafe
Open fracture contamination is severe
Bone loss is substantial
Patient factors make large internal implants undesirable

Limited articular fixation can be combined with a circular frame.

Primary ankle arthrodesis

Consider primary tibiotalar fusion in selected catastrophic injuries with:

Nonreconstructible articular comminution
Extensive cartilage destruction
Major bone loss
Severe contamination in a carefully selected reconstructive strategy

It is not routine for most pilon fractures.

Postoperative care

Begin ankle motion once wounds are stable and fixation permits.

Non weight bearing is commonly required for approximately 10 to 12 weeks, sometimes longer with severe comminution.

Advance loading only with convincing evidence of healing.

Complications are common:

Wound necrosis
Deep infection
Osteomyelitis
Nonunion
Metaphyseal malunion
Ankle stiffness
Post traumatic osteoarthritis
Chronic pain
Secondary ankle arthrodesis

Even an anatomically reconstructed pilon fracture may develop arthritis because the initial axial impact can cause irreversible cartilage injury.

Hip Dislocation

Overview

Clinical Features

Diagnosis

Management

Overview

Clinical Features

Diagnosis

Management