1. Summary
2. How are they classified?
3. How common are they and how do they occur?
4. What do they look like - clinically?
5. What radiological investigations should be ordered?
6. What do they look like on x-ray?
7. When is reduction (non-operative and operative) required?
8. Do I need to refer to orthopaedics now?
9. What is the usual ED management for this fracture?
10. What follow-up is required?
11. What advice should I give to parents?
12. What are the potential complications associated with this injury?

1. Summary

• Elbow dislocations usually refers to ulnohumeral dislocations (see image below). Radiocapitellar dislocations are part of the umbrella of Monteggia lesions and are  discussed elsewhere 
• Subluxation of the annular ligament ('Pulled Elbow' or ‘Nursemaid’s Elbow) is also discussed elsewhere

• Elbow dislocation in children almost always arises from a fall on the outstretched hand, with the elbow in an extended position 
• Elbow dislocations can be divided into simple (no fractures) or complex (with associated fractures)
• A number of fractures can occur in the setting of elbow dislocations, and these should be diagnosed accurately and early to avoid deleterious outcomes 
• Most elbow dislocations can be reduced in ED under sedation. Following reduction, flexion of the elbow activates triceps tension and helps keep joint enlocated 
• Most simple dislocations (without fractures) have good outcomes if rehabilitated appropriately. Patients must have early follow-up with early motion commenced no later than 2 weeks. Patients should be referred to orthopaedic outpatient follow-up within 1-2 weeks 
• Complex dislocations require early advanced imaging in the form of CT and/or MRI
• BEWARE seemingly innocent “specks” on an elbow x-ray following a dislocation as these can represent serious bony and/or ligamentous injuries. These are termed TRASH lesions (The Radiographic Appearance Seems Harmless). If in doubt, obtain further imaging in the form of CT/MRI

2. How are elbow dislocations classified?

• Simple - no associated fractures
• Complex - with associated fractures
  • Medial epicondyle
    • Most common associated fracture
    • Beware the entrapped medial epicondyle following relocation
    • Beware ulnar nerve neuropathy
  • Valgus posterolateral rotatory
    • Radial head and/or capitellar shear fracture
    • Medial collateral ligament +/- lateral collateral ligament
  • Varus posteromedial rotatory
    • Coronoid process fracture
    • Lateral collateral ligament +/- medial collateral ligament

3. How commonly do they occur?

• Elbow dislocations are common pediatric injuries 
• Most medial epicondyle fractures in children actually represent self-reduced elbow dislocations

4. What do they look like clinically?

• On History
  • Fall on outstretched hand with the elbow in extension
  • More common in girls than boys 
  • At times a dislocation may occur (and be described in history) but the joint has reduced before arrival in Emergency.  Careful workup for associated injuries is required as they can be easily missed.
• On Examination
  • Possible deformity in appearance of elbow
  • Inability to move elbow
  • Possible neurological compromise

5. What Radiological Investigations should be ordered?

• X-rays should be performed on all patients, pre and post reduction
  • These should include AP and lateral
• If any suspicion of a fracture, or even an abnormal “speck” on xray (known as a TRASH lesion - The Radiographic Appearance Seem Harmless) - further imaging should be performed in the form of either a CT or MRI

6. What do they look like on x ray?

• Discontinuity between the ulnohumeral joint is obvious

• More subtle is a medial epicondyle fracture, or an “entrapped” medial epicondyle fracture.
  • These arise from valgus dislocations where the medial epicondyle is pulled off by the attached tendons. When the displacement is extreme, the epicondyle can be entrapped in the elbow joint.
  • See image below where green arrow indicate where medial epicondyle should be, and red arrow indicate that it is entrapped inside the ulnohumeral joint space

• Even more subtle is the partially reduced elbow dislocations, with residual subluxation due to instability and/or loose bodies (see below 2 images of same elbow, following attempted reduction, showing eccentrically reduced joint and loose bodies in lateral compartment )

7. When is reduction (non-operative and operative) required?

• Elbow dislocations should undergo closed reduction emergently in ED.
• Even if reduction is incomplete, it is better than having it totally dislocated!
• Complex elbow dislocations with fracture fragments may require further completion of reduction in theatre

8. Do I need to refer to Orthopaedics now?

• Immediate referrals should be made in the following circumstances
  • Any elbow dislocations with associated fractures (eg medial epicondyle, olecranon, capitellum)
  • Any elbow dislocations with associated neurological compromise
  • Any irreducible or only partially reducible dislocations

Other dislocations which are able to be reduced in the ED can be followed up in orthopaedic fracture clinic as below.

9. What is the usual ED management for this fracture?

• Closed reduction under sedation
• This usually involves traction/counter-traction, followed by flexion of the elbow. The elbow then should be immobilized in flexion (90 deg), in a backslab and sling, to help keep it in joint
• Pre- and post- reduction x-rays
• CT/MRI if any suspicion of associated fractures

10. What follow up is required?

• ALL elbow dislocations should be followed up early in orthopaedic clinic (1-2 weeks)
  • For simple dislocations, this is to ensure maintenance of concentric reduction, and commencement of early mobilization at 2 weeks (evidence shows that immobilization of simple elbow dislocations >2 weeks results in long-term stiffness).
  • For complex dislocations, this is to ensure fractures are not missed and are being followed up appropriately

11. What advice should I give to parents?

• Simple elbow dislocations generally have good outcomes.
• Watch for neurological compromise on discharge
• Unless told otherwise by orthopaedics, gentle supervised mobilization must start at 2 weeks to ensure no long-term stiffness.

12. What are the potential complications of this injury?

• The worst outcomes arise from missed fractures or TRASH lesions. These can result in permanent malunion/nonunion and stiffness
• Acute neurological injuries can occur from elbow dislocations, although these are rare
• Persistent instability can occur if major ligament/bony instability is not treated appropriately.

References

1. Waters PM, Beaty J, Kasser J. Elbow “tRASH” (The radiographic appearance seemed harmless) lesions. J. Pediatr. Orthop. 2010;30(SUPPL. 2):77–81. doi:10.1097/BPO.0b013e3181c18a9f
2. Kozin SH, Abzug JM, Safier S, Herman MJ. Complications of pediatric elbow dislocations and monteggia fracture-dislocations. Instr. Course Lect. 2015;64:493–8. 
3. [book]  Waters P, Bae D. Pediatric Hand and Upper Limb Surgery: A Practical Guide. 2nd ed. Boston: 2020.

Last updated December 2020