What is the diagnosis?

Radial head subluxation (RHS), also known as “nursemaid’s elbow,” “pulled elbow” or annular ligament displacement.

Image 1. Case courtesy of Leonardo Lustosa, Radiopaedia.org, rID: 152640 [1].

What is the mechanism of injury?

In RHS, axial traction of the distal arm causes a portion of the annular ligament to slip proximally over the radial head and into the radiohumeral joint. It can become trapped leading to persistent elbow pain and limited mobility. This most commonly occurs due to axial traction of a pronated forearm and extended elbow [3]. The classic history is an adult pulling on a child’s arm followed by the child complaining of pain in their elbow and refusing to move their arm.

• Pearl: 80% of cases occur in individuals aged one to three years old. RHS is quite rare in children older than 5, however cases have been reported as old as 11 years old [2]. 

What physical exam findings are expected?

Physical exam demonstrates a non-distressed child with their elbow held in partial flexion and wrist pronated. There may be mild tenderness over the radial head, however there should be no evidence of deformity, crepitus, ecchymosis or focal edema to suggest fracture [4].

What is the management in the ED?

Radial head subluxation is diagnosed clinically with a combination of history describing axial pulling of the arm and physical exam as above. X-ray imaging is not required for diagnosis.

Although various management techniques exist, the preferred method is performed by hyperpronation of the forearm. This involves the clinician supporting the patient’s elbow by providing pressure on the lateral aspect of the humeral head as the other hand hyper-pronates the forearm. A click may be felt over the radial head during reduction [5].

Another method described is the supination/elbow flexion technique. This involves the clinician supporting the patient’s elbow with one hand, with the other hand gently pulling traction on the forearm followed by supination and flexion of the elbow [5].

• Pearl: If the patient’s history and physical exam are highly suspicious for RHS, radiographs are not needed. However, if the history is atypical, exam findings are concerning for fracture or dislocation, or there is persistent pain despite multiple reduction techniques, a radiograph is recommended to evaluate for fracture [4].

• Pearl: In patients older than 5, RHS is relatively uncommon and patients presenting with arm pain and decreased mobility typically require radiograph to evaluate for fracture or dislocation [3].

When do you consult orthopedics?

After successful reduction of RHS resulting in improved pain and normal range of motion, no further treatment or intervention is indicated. Referral to sports medicine or orthopedic surgery is not required if the patient remains asymptomatic. In the event of persistent pain or limited range of motion despite multiple reduction attempts and negative radiograph, the patient should be evaluated in two to three days by the patient’s primary care doctor or by orthopedics.

What counseling would you provide the parents to avoid future episodes?

Parents should be counseled to avoid sudden tugging of the arm, picking up the child by the hands or wrists or forcefully removing clothing.