Pulled Elbow / Radial Head Subluxation
- Nursemaid's (pulled) elbow is a SUBLUXATION of the RADIAL HEAD beneath the ANNULAR LIGAMENT - the ligament slips partially over the radial head; it is NOT a true dislocation.
- The classic mechanism is sudden AXIAL TRACTION on an EXTENDED, PRONATED arm - typically a child lifted or swung by the hand/wrist; it is very common in children roughly 1-4 years old.
- The child holds the arm still, slightly FLEXED and PRONATED, close to the body, refuses to use it, but has NO significant swelling, deformity or focal bony tenderness.
- It is a CLINICAL diagnosis from this classic history and presentation; RADIOGRAPHS are NOT routinely needed and are usually normal - obtain them only to EXCLUDE a FRACTURE when the history is atypical/traumatic, there is swelling/point tenderness, or reduction fails.
- Treatment is gentle MANUAL REDUCTION in the clinic/ED: the HYPERPRONATION manoeuvre is MORE effective (fewer first-attempt failures) than the supination-flexion manoeuvre on Cochrane evidence and should be tried first; a palpable 'click' and rapid return of normal arm use confirm success (~80% success).
- Recurrence is common until the child grows; persistent failure to use the arm after reduction, or an atypical picture, mandates radiographs and orthopaedic referral to exclude a fracture or other pathology.
- “Mechanism = axial pull on an EXTENDED PRONATED arm; the child holds it pronated and won't use it, with NO swelling/deformity.
- “It is a clinical diagnosis - don't routinely X-ray; image only to exclude a fracture (atypical history, swelling, point tenderness, failed reduction).
- “Reduce with HYPERPRONATION first (Cochrane: fewer failures than supination-flexion, NNT ~6); success = click + the child uses the arm within minutes.
Classic pull history, child 1-4 years, arm held pronated and slightly flexed, refuses to use it, but no swelling, no deformity, no focal bony tenderness. Reduce clinically - no X-ray needed.
Swelling, deformity, focal bony tenderness, a fall/direct-trauma mechanism, an atypical history (consider non-accidental injury), or failed reduction. Radiograph before manipulation and refer as needed.
Anatomy & Mechanism
The annular ligament encircles the head and neck of the radius, securing it against the radial notch of the ulna at the proximal radio-ulnar joint while allowing rotation (pronation/supination). In young children the radial head is relatively small and incompletely ossified and the annular ligament is lax, so a sudden axial pull on an extended, pronated forearm can let the radial head slip partially out from under the annular ligament, which becomes interposed - a subluxation. This is why the typical cause is a child being lifted or swung by the hand (the practice should be discouraged), and why the injury becomes rare once the radial head enlarges with growth.
Clinical Presentation & Diagnosis
- A young child (commonly 1-4 years) who suddenly stops using one arm after a pull
- The arm is held close to the body, slightly flexed and pronated
- Little or no pain at rest, no swelling, no deformity
- Resists supination and overhead use of the arm
- Clinical - the classic history plus this presentation is diagnostic
- Radiographs are NOT routine and are usually normal
- Image only to exclude a fracture: atypical/traumatic history, swelling, focal bony tenderness, or failed reduction
Reduction
Reduction is a simple bedside manoeuvre. With the elbow at about 90 degrees, the two recognised techniques are:
- Hyperpronation - firmly pronate the forearm/wrist (sometimes with slight elbow flexion).
- Supination-flexion - supinate the forearm and then flex the elbow fully.
On Cochrane evidence the hyperpronation manoeuvre has fewer first-attempt failures than supination-flexion (failure ~9% vs ~26%, risk ratio ~0.35, NNT ~6), so it should be tried first. A successful reduction often produces a palpable or audible 'click' over the radial head, and the child typically resumes using the arm within minutes (the most reassuring sign). Office/ED reduction has roughly an 80% success rate with no significant complications.
If the child uses the arm normally after reduction, no immobilisation is needed and they can go home with advice to avoid pulling/swinging by the hand (recurrence is common until the child grows). If two attempts fail, or the child still will not use the arm, splint the arm and obtain radiographs / refer to exclude a fracture or other pathology. Always reconsider the diagnosis (and safeguarding) if the history does not fit.
Evidence & Key Studies
Manipulative interventions for reducing pulled elbow in young children
- Across 9 trials (906 children), hyperpronation had fewer first-attempt failures than supination-flexion: 9.2% versus 26.4% (RR 0.35, 95% CI 0.25-0.50).
- Estimated number needed to treat of 6 (95% CI 5-8) to avoid one additional first-attempt failure using hyperpronation.
- Evidence is low-quality and a high-quality RCT is still needed, but pronation appears more effective at first attempt.
Pulled elbow in children
- Pulled elbow is a radial head subluxation from axial traction or a sudden pull of the extended, pronated arm; the practice of swinging children by the hands should be abandoned.
- The child holds the affected arm close to the body without considerable pain, swelling or deformity; once a fracture is excluded it is a clinical diagnosis.
- Office reduction has ~80% success with no complications; the hyperpronation manoeuvre is better than supination-flexion and should be tried first.
According to PubMed, the superiority of hyperpronation (with the quoted failure rates, RR and NNT) comes from the cited Cochrane review, and the clinical description/management from the cited review. The annular-ligament mechanism is standard, well-established anatomy.
Clinical Decision Scenarios
Practise clinical reasoning and management decisions out loud
“A 2-year-old is brought in refusing to use the right arm after the parent lifted her by the hand. There is no swelling or deformity and she holds the arm pronated. What is the diagnosis, how do you confirm it, and how do you treat it?”
“The reduction fails after two attempts and the child still will not use the arm. What now, and why does pulled elbow happen in young children but not adults?”
Mnemonics & Memory Aids
PULLED
Hook:A PULLED elbow: pull on a pronated arm, radial head under the annular ligament, reduce by hyperpronation.
REDUCE
Hook:REDUCE a pulled elbow: hyperpronate at 90 degrees; click and arm use = done.
What & why
- Radial head subluxation under the annular ligament (not a dislocation)
- Axial traction on an extended, pronated arm (lifting/swinging by the hand)
- Ages ~1-4; rare after ~5 (radial head enlarges)
Presentation
- Won't use the arm; held close, slightly flexed and pronated
- No swelling, deformity or focal bony tenderness; little pain at rest
- Resists supination/overhead use
Diagnosis
- Clinical - no routine radiographs (usually normal)
- X-ray only to exclude a fracture (atypical/traumatic, swelling, tenderness, failed reduction)
- Consider NAI if the history does not fit
Treatment
- Hyperpronation first (Cochrane: failure ~9% vs ~26%, RR 0.35, NNT ~6)
- Then supination-flexion if needed; success = click + arm use within minutes (~80%)
- If two attempts fail: splint, X-ray, refer; advise against pulling by the hand (recurrence common)