Mechanism of Injury
The metaphysis and developing epiphysis of the proximal radial head articulate with the ulnar in the radial notch. During pronation and supination of the hand the radial head principally rotates in the radial notch, while in flexion and extension of the elbow, anterior and posterior glide occurs at the capitulum. The joint between the radius and ulnar is maintained by a ligamentous cuff comprising the radial collateral ligament and the annular ligament.
When a sufficient tractioning with forceful pronation is exerted on the young child's arm, the annular ligament may be torn or stretched causing widening of the lateral joint space and entrapment of ligament fibers between the head of the radius and the joint surface. This produces a condition in which any movement of the elbow joint will be painful for the child. Studies have indicated that a transverse tear usually occurs where the annular ligament attaches to the radius and that part of the ligament capsule may become trapped in the joint between the radius and ulnar.
Presenting Symptoms
A child with a "pulled-elbow" will usually experience a sudden onset of pain at the elbow following a typical forearm traction type maneuver, and will usually hold the arm at their side in a position of wrist pronation with the elbow in slight flexion. The child will not move the arm, thereby creating a condition known as pseudo-paralysis. All attempts at passive range of motion will be resisted by the child due to pain from the trapped ligament fibers. Palpation of the radial head will reveal an area of tenderness. Radiographs of the elbow are usually normal and are not usually necessary if the history of the injury specifically identifies a traction type etiology.
Treatment
Treatment involves grasping the child's wrist and elbow and applying sudden firm supination while extending the elbow. This action is designed to release the ligament tissue which is locked in the joint. Occasionally a click may be heard concurrent with this adjustment. Immediate relief of pain usually results, particularly if the injury is a recent one. Sometimes there is a short period of crying for a minute or two after the release. The earlier after the injury that the child is treated, the more rapid will be the recovery. Alternatively, if the problem has existed for some days then relief from pain may not be so rapid. Bracing and immobilization is usually not required if this is the first occurrence of this condition. For repeat injuries however, a posterior splint may be applied for several days.
Prognosis
Parents should be made aware of the damage to the ligament structures of the elbow and cautioned not to lift the child by the arm as the pulled-elbow condition can reoccur up until about age five.
Being a family practitioner, most chiropractors will encounter a child with nursemaid's elbow at some time in their practice. When this occurs, ability to manage this condition quickly and effectively is important both for the child and the "nursemaid."
Peter Fysh, DC
San Jose, California
Editor's note: Dr. Fysh is currently conducting pediatric seminars. He may be contacted at 1-800-999-7337.
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