Presentation of Radial Head Dislocation in a 3-Year-Old
A 3-year-old with isolated radial head dislocation typically presents with elbow pain, limited range of motion (particularly restricted supination and pronation), and refusal to use the affected arm following trauma—though the mechanism of injury may be unwitnessed or unclear.
Clinical Presentation
The child will demonstrate:
- Pain localized to the elbow region following a fall or traumatic event
- Marked limitation in forearm rotation, with restricted supination and pronation being the hallmark finding
- Limited elbow flexion-extension arc (often 0-90° or less in acute cases) 1, 2
- Reluctance or refusal to use the affected extremity
- Possible visible deformity depending on the direction of dislocation (anterior-medial being most common in pediatric cases) 2, 3
Key Clinical Pitfall
The history of trauma may be unwitnessed or seemingly minor, making this injury easy to miss initially 4, 5. In a 3-year-old, the child may not be able to articulate the mechanism clearly, and caregivers may report only that the child "won't use the arm" after a fall.
Direction of Dislocation
In pediatric patients, anterior-medial dislocation is most frequently reported 2, 3, though lateral dislocations also occur 4. This differs from adults where posterior dislocations predominate.
Physical Examination Findings
Look specifically for:
- A characteristic "sling effect" during attempted forearm rotation—the forearm may rotate from pronation to supination but snaps back to neutral, which is pathognomonic for capsular interposition 2
- Palpable prominence of the radial head in an abnormal position
- Neurovascular status must be documented, though neurovascular injury is uncommon with isolated dislocations
Diagnostic Imaging
Standard anteroposterior and lateral radiographs of the elbow are the initial and appropriate imaging study 6. On radiographs, confirm:
- The radial head does not align with the capitellum on all views
- Rule out associated ulnar fracture or plastic deformation (Monteggia variant) 1, 5
- Assess for any associated fractures
Critical Diagnostic Consideration
Isolated traumatic radial head dislocation in a 3-year-old is extremely rare 4, 5. When identified, it is frequently missed on initial presentation because clinicians may not consider it in the differential diagnosis 5. The injury is so uncommon that it may not fit standard Monteggia-variant classifications, contributing to delayed diagnosis 5.
Associated Injuries to Exclude
While the question asks about isolated dislocation, you must actively exclude:
- Ulnar plastic deformation (may be subtle on radiographs) 1, 5
- Olecranon fractures (even undisplaced) 3
- Annular ligament disruption (cannot be seen on plain films but is almost always present)
Why This Matters for Morbidity
Early recognition is critical—delayed diagnosis leads to:
- Difficulty with closed reduction (soft tissue interposition becomes more likely) 1, 2
- Need for open reduction and ligament reconstruction 5
- Permanent limitation of forearm rotation and elbow deformity 1
- Unpredictable surgical outcomes when treatment is delayed 1
The earlier this injury is detected in a 3-year-old, the more likely closed reduction will succeed and the better the functional outcome 1.