Courtesy: Manoj Padman, Ashok Shyam, IORG, OrthoTV

Epidemiology

• Rare injury, accounting for less than 1 percent of pediatric fractures.
• Usually results from high energy trauma.
• Associated with a high risk of missed diagnosis, complications, and poor outcomes.

Vascular Anatomy

Main blood supply

• Medial circumflex femoral artery provides the principal blood supply.
• Retinacular branches are the major vascular supply.

Other important points

• The physis acts as a watershed zone and limits metaphyseal blood supply.
• Ligamentum teres provides only a minor temporary blood supply in early childhood.

Clinical relevance

• Fractures closer to the physis have a higher risk of avascular necrosis.
• Intracapsular hematoma may cause vascular tamponade and compromise blood flow.

Delbet Classification

Type I: Transphyseal

• Fracture through the physis, with or without hip dislocation.
• Highest risk of avascular necrosis.
• Rare injury.

Type II: Transcervical

• Most common type.
• Moderate risk of avascular necrosis.

Type III: Cervicotrochanteric (Basicervical)

• Lower risk of avascular necrosis.
• Higher incidence of coxa vara and malunion.

Type IV: Intertrochanteric

• Best prognosis.
• Lowest risk of avascular necrosis.
• Malunion is more common.

Key concept

• More proximal fractures have a greater risk of avascular necrosis.
• More distal fractures have a lower risk of avascular necrosis but a greater risk of deformity.

Investigations

Radiographs

• Anteroposterior pelvis including both hips.
• Internal rotation view.

Advanced imaging

• MRI or CT for suspected occult fractures.
• MRI or CT when low energy trauma suggests a pathological fracture.

Factors Affecting Outcome

Non modifiable factors

• Age.
• Fracture type.
• Initial displacement.

Modifiable surgeon related factors

• Early surgery.
• Anatomical reduction.
• Stable fixation.

Management Principles

Early intervention

• Perform surgery ideally within 24 hours.
• Decompress intracapsular hematoma using aspiration or capsulotomy.

Reduction

• Aim for anatomical reduction.
• Attempt closed reduction first.
• Proceed to open reduction if anatomical reduction cannot be achieved.
• Do not accept malreduction.

Fixation

Principles

• Stable fixation is more important than preservation of the physis.
• Crossing the physis is acceptable if required for stability.

Fixation according to age

• Younger children: Smooth Kirschner wires with hip spica.
• Older children: Cannulated screws.
• Type III and Type IV fractures may require side plate fixation.

Postoperative Care

• Hip spica in younger children.
• Delayed weight bearing.
• Serial radiographic follow up.

Complications

Major complication

• Avascular necrosis.

Other complications

• Coxa vara.
• Nonunion.
• Growth arrest with limb length discrepancy.
• Infection.
• Chondrolysis.

Risk Factors for Avascular Necrosis

• Fracture type.
• Degree of displacement.
• Delay in treatment.
• Older age.

Common Clinical Pitfalls

Missed diagnosis

• Children may present with knee or thigh pain.
• Always examine the hip.

Missing a pathological fracture

• Low energy injuries should raise suspicion for infection, tumor, or metabolic bone disease.

Inappropriate conservative treatment

• Suitable only for undisplaced fractures.
• Most displaced fractures require surgery.

Avoiding fixation across the physis

• Inadequate fixation leads to instability and poor outcomes.

Poor reduction or fixation

• Common cause of treatment failure.

Exam Pearls

• Most important complication is avascular necrosis.
• Most important prognostic factor is the fracture type.
• Most important modifiable factor is early surgery with anatomical reduction and stable fixation.
• Golden rule: Anatomical reduction and stable fixation.