Radial head subluxation, common among children ages 2 to 3 years old, is caused by traction on the forearm and usually manifests as refusal to move the elbow (pseudoparalysis).
In adults, the radial head is wider than the radial neck; consequently, the head cannot fit through the ligaments that tightly surround the neck; therefore, it does not easily become subluxed. However, in children about 2 to 3 years old, the radial head is no wider than the radial neck and can easily slip through these ligaments (radial head subluxation).
Subluxation results from traction on the forearm, as when a caregiver pulls a child forward or catches the child by the wrist during a fall.
(See Overview of Dislocations.)
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Symptoms and Signs of Radial Head Subluxations
Symptoms of radial head subluxation may include pain and tenderness. Most young children cannot describe their symptoms and simply present with unwillingness to move the affected arm. The radial head may be only mildly tender.
Diagnosis of Radial Head Subluxations
Usually history and physical examination alone
Typically after a traction and rotational injury (eg, twisting of the arm while spinning around with a sibling) the child protects the affected arm and is unwilling to move it. Plain radiographs are normal and considered unnecessary by some experts when patients have a clear history of a traction injury, unless an alternate diagnosis is clinically suspected (1).
Using a reduction maneuver may be diagnostic and therapeutic.
Diagnosis reference
1. Eismann EA, Cosco ED, Wall EJ: Absence of radiographic abnormalities in nursemaid's elbows. J Pediatr Orthop 34 (4):426–431, 2014. doi: 10.1097/BPO.0000000000000126
Treatment of Radial Head Subluxations
Reduction
Reduction may be performed using:
Supination-flexion
Hyperpronation
Neither technique requires sedation or analgesia; the child experiences mild pain only for a few seconds. Hyperpronation has a higher first-attempt success rate (1). (For detailed instructions see also How To Reduce a Radial Head Subluxation.)
In supination-flexion, the elbow is completely extended and supinated, then flexed. A subtle palpable pop or click is often detected when the radial head resumes its normal position.
In hyperpronation, the clinician supports the child's arm at the elbow and places moderate pressure with a finger on the radial head. The clinician then grips the distal forearm with the other hand and hyperpronates the forearm. A pop can be felt at the radial head when it is reduced.
Children usually start to move the elbow after approximately 10 to 20 minutes. If they do move it, radiographs and immobilization are unnecessary. If they do not move or use the elbow, a second reduction should be attempted.
If pain or dysfunction persists > 24 hours, incomplete reduction or an occult fracture should be suspected. Radial head subluxation recurs in 27 to 46% of children (2, 3).
Treatment references
1. Bek D, Yildiz C, Köse O, et al: Pronation versus supination maneuvers for the reduction of 'pulled elbow': A randomized clinical trial. Eur J Emerg Med 16 (3):135–138, 2009. doi: 10.1097/MEJ.0b013e32831d796a
2. Schunk JE. Radial head subluxation: epidemiology and treatment of 87 episodes. Ann Emerg Med. 1990;19(9):1019-1023. doi:10.1016/s0196-0644(05)82567-3
3. Kimura M, Taketani T, Kurozawa Y. Parental questionnaire study showed that annular ligament displacement was common in three-year-old children and almost a half had reoccurring episodes. Acta Paediatr. 2018;107(11):1983-1985. doi:10.1111/apa.14422
Key Points
Radial head subluxation, common among young children, can occur when a caregiver pulls a reluctant child forward or catches the child by the wrist during a fall.
Most patients cannot describe their symptoms; the only indication of the injury may be unwillingness to move the affected arm.
Diagnose based on history unless an alternate diagnosis is suspected.
Treat by reducing the joint (using supination-flexion or hyperpronation); a subtle palpable pop or click is often detected when the radial head resumes its normal position.
