What is the management for a suspected radial head dislocation in a 2-year-old with an abnormal radiocapitellar line on multiple views?

Management of Radial Head Dislocation in a 2-Year-Old

Immediate orthopedic consultation is required for a 2-year-old with confirmed radial head dislocation on multiple radiographic views, as this represents a true traumatic dislocation requiring urgent closed reduction under sedation or general anesthesia, with open reduction reserved for failed closed attempts.

Initial Assessment and Differential Diagnosis

Critical Distinction: True Dislocation vs. Nursemaid's Elbow

• True radial head dislocation with abnormal radiocapitellar line on multiple views represents a significant traumatic injury requiring orthopedic intervention 1
• This differs from radial head subluxation (nursemaid's elbow), where radiographs typically show radiocapitellar line displacement ≤3 mm and the injury reduces with simple manipulation 2
• In true dislocations, the radiocapitellar line displacement exceeds 3 mm and indicates complete disruption of the radiocapitellar articulation 2

Mechanism and Associated Injuries

• Evaluate for concomitant injuries including ulnar fractures (Monteggia fracture-dislocation pattern), which are common in pediatric forearm trauma 3
• Assess for elbow dislocation or coronoid fractures, as radial head dislocations can present with complex injury patterns 4
• Document neurovascular status, particularly radial and posterior interosseous nerve function 5

Immediate Management Algorithm

Step 1: Confirm Diagnosis and Rule Out Complications

• Obtain complete elbow radiographic series including AP, lateral, and oblique views to fully characterize the injury 1
• The radiocapitellar line should bisect the capitellum on all views; persistent abnormality confirms dislocation 1, 2
• Consider CT imaging if fracture patterns are complex or reduction appears incomplete 4

Step 2: Urgent Orthopedic Referral

• All confirmed radial head dislocations require orthopedic management - this is not an injury for emergency department reduction alone 3, 4
• Timing is critical: delayed diagnosis and treatment lead to chronic complications including pain, stiffness, loss of forearm rotation, and progressive dysplasia 5, 3

Step 3: Reduction Strategy

Initial approach: Closed reduction under general anesthesia or deep sedation 3, 4

• Adequate muscle relaxation is essential for successful closed reduction 3
• Reduction should be performed under fluoroscopic guidance to confirm anatomic restoration 4
• Post-reduction radiographs must demonstrate normal radiocapitellar alignment on all views 1

If closed reduction fails: Open reduction is mandatory 5, 3, 4

• Failed closed reduction typically indicates soft tissue interposition 3, 4
• Common blocks to reduction include:
  • Buttonholing of radial head through anterior joint capsule 3
  • Capsular interposition in the radiocapitellar joint 3
  • Transbrachialis buttonholing with radial head suspended by brachialis tendon 5
• Open reduction allows direct visualization, removal of interposed tissue, and confirmation of anatomic reduction 5, 3

Critical Pitfalls to Avoid

Delayed or Missed Diagnosis

• Radiographic assessment of the radiocapitellar line is mandatory in all pediatric elbow and forearm injuries at presentation 1
• In 8-10% of cases, the dislocation is initially overlooked on radiographs 1
• Tardy displacement can occur: the radial head may spontaneously reduce initially, then redislocate days later while immobilized 1
• Repeat radiographs are required when the cast is removed to ensure maintained reduction 1

Inadequate Reduction Attempts

• Multiple failed closed reduction attempts without orthopedic expertise can cause additional soft tissue damage 4
• Accepting near-anatomic reduction is unacceptable - only perfect anatomic alignment prevents long-term complications 5, 3

Failure to Consider Non-Accidental Trauma

• In a 2-year-old with significant elbow trauma, consider the possibility of abuse, particularly if the mechanism is unclear or inconsistent 6
• Common accidental fractures in this age group are distal humeral and distal radius/ulna from short falls, not isolated radial head dislocations 6

Post-Reduction Management

• Immobilization in long-arm cast with elbow at 90 degrees flexion for 3-4 weeks 3
• Serial radiographs at 1-2 weeks to confirm maintained reduction 1
• Early range of motion exercises after immobilization period to prevent stiffness 5
• Expected outcome with successful reduction: full return to activity with normal range of motion by 3-6 months 5, 4

Long-Term Consequences of Inadequate Treatment

• Chronic radial head dislocation results in progressive complications including persistent pain, limited forearm rotation, cubitus valgus deformity, elbow instability, and potential neuropathy 5, 3
• These complications are preventable with early recognition and appropriate anatomic reduction 3, 4