Nursemaid's elbow is a dislocation of the elbow joint caused by a sudden pull on the extended pronated arm, such as by an adult tugging on an uncooperative child.
In radial head subluxation, there is little complaint of pain, and the patient generally reports pain in the distal forearm. Radial head subluxation is a common pediatric presentation generally occurring between the ages of 1 and 3 years. The mean age of presentation is just older than 2 years.
The pathologic lesion is generally a tear in the attachment of the annular ligament to the periosteum of the radial neck, with the detached portion becoming trapped between the head of the radius and the capitellum.
The older child will usually point to the dorsal aspect of the distal forearm when asked where it hurts. This may mislead one to suspect a buckle fracture of the distal radius.
Signs and symptoms
Radial head subluxation
- The child stops using the arm, which is held flexed and pronated.
- Minimal swelling.
- All movements are permitted except supination.
- Caused by longitudinal traction with the wrist in pronation, although in a series only 51% of patients were reported to have this mechanism, with 22% reporting falls, and patients less than 6 months of age noted to have the injury after rolling over in bed.
- If a child is noted to have this injury, investigation of child abuse is generally prompted by other suggestive features such as fractures or burns
- Parents should not attempt these maneuvers at home unless advised by a physician.
Flexion and supination
Subluxation of the radial head in children:
- Therapeutic goal is reduction.
- No premedication is required.
- X-rays are generally not obtained in a patient with a nontender arm (positioning the child for X-rays may result in reduction).
- Indication for X-rays: child not using arm 30 min after a reduction; external signs of trauma such as swelling, abrasions, or ecchymosis.
- Inform child and caregiver that the reduction may be uncomfortable, but the discomfort will end quickly after reduction.
- Perform reduction by firm supination of the forearm with the other hand supporting the elbow in 90º of flexion, feeling and listening for the 'click' as full supination is achieved (although 'click' signifies reduction, absence of a 'click' is noted in successful reductions)
- The child resumes use of the arm promptly after reduction (within 30 minutes)
- If the elbow does not reduce, consider the following diagnoses: fractures, joint infection, tumors, or osteomyelitis
- Assure and document that the child has full, unrestricted, painless use of the arm after reduction
- Some recommend that the arm remains in a sling for one week.
- Caregivers are cautioned against repeated traction injury to the elbow.
- Recurrent subluxation may result in need for surgery if the patient does not outgrow condition.
- A strategy of pronation was found by one study to be more successful than the above technique
This entity has also been reported in infants younger than six months and in older children up to the preteen years. There is a slight predilection for this injury to occur in girls and in the left arm. The classic mechanism of injury is longitudinal traction on the arm with the wrist in pronation, as occurs when the child is lifted up by the wrist. There is no support for the common assumption that a relatively small head of the radius as compared to the neck of the radius predisposes the young to this injury.