Courtesy: Saqib Rehman MD, Associate Professor, Director of Orthopaedic Trauma, Temple University, Philadephia, Pennsylvania, USA

 

Pediatric Trauma Panel Discussion

Posterior Hip Dislocation in Adolescents

Key points

• Commonly caused by high energy trauma such as sports injuries and road traffic accidents.
• Usually occurs in adolescents with open physes.
• Always assess for associated femoral head injury.
• Always assess for acetabular fracture.
• Always assess for physeal injury (Salter Harris Type I).

Important concept

• Forceful reduction may cause physeal separation of the femoral head.
• This represents an iatrogenic Salter Harris Type I injury.

Management

• Posterior hip dislocation is an orthopaedic emergency.
• Reduce the hip ideally within 6 hours to reduce the risk of avascular necrosis.
• Gentle reduction is preferred.
• Reduction in the operating room may provide better control.
• Fluoroscopy may be useful during reduction.

Post reduction imaging

• Pelvic radiographs.
• CT scan to identify associated fractures.
• MRI in children to detect labral injuries and osteochondral lesions.

Complication

• Avascular necrosis is the most important complication.
• Risk increases with delayed reduction.
• Risk increases with associated physeal injury.

Proximal Humerus Fracture with Shoulder Dislocation

Case summary

• Rare injury combination in children.
• More commonly seen in a 9 year old child.

Important concept

• Shoulder dislocations are uncommon in children.
• Physeal or metaphyseal fractures are more common than pure dislocations.

Management

• Urgent closed reduction of the shoulder should be performed first.
• Fracture treatment is guided by the excellent remodeling potential of the proximal humerus.

Acceptable alignment (approximately 9 years of age)

• Up to 100 percent displacement may be accepted.
• Up to 40 to 50 degrees of angulation may be acceptable.
• Varus deformity greater than 35 to 40 degrees should be avoided.

Indications for surgery

• Irreducible shoulder dislocation.
• Severe malalignment.
• Older children, particularly over 12 years of age.

Fixation

• Percutaneous pinning when surgical fixation is required.
• Technically demanding procedure.

Outcome

• Excellent remodeling potential.
• Good functional recovery despite imperfect reduction.

Remodeling Potential of the Proximal Humerus

Key concept

• Approximately 80 percent of humeral growth occurs at the proximal humeral physis.
• This provides exceptional remodeling capacity in children.

Adolescent Femoral Shaft Fractures

Retrograde femoral nailing

• Contraindicated when the distal femoral physis remains open.
• Avoid if more than 2 years of growth remain.
• Appropriate only in skeletally mature adolescents.

Complication

• Growth arrest.
• Limb length discrepancy.

Exam Pearls

• Posterior hip dislocation requires emergency reduction within 6 hours.
• Physeal injury during reduction is an important pediatric concern.
• MRI is superior to CT for detecting labral and cartilage injuries.
• Proximal humerus fractures in children usually require nonoperative treatment.
• Children younger than 10 years have remarkable remodeling potential.
• Accept substantial displacement and angulation in younger children.
• Avoid retrograde femoral nailing in patients with an open distal femoral physis.