By Jacob W. Ufberg, MD
Radial head subluxation (RHS), also known as nursemaid’s elbow or pulled elbow, is a common reason for pediatric emergency department (ED) visits. Most commonly occurring in children between the ages of 1 and 3 years, RHS has been reported in infants younger than 6 months,1,2 and in older children in their pre-teens.3 Most children present with the "classic" mechanism of longitudinal traction to the extended arm with the wrist in pronation, as may occur when lifting a child by the wrist to prevent a fall or while swinging a child by the arms. The anatomic mechanism of injury is generally a small tear in the attachment of the annular ligament to the periosteum of the radial neck, allowing the detached portion to become entrapped between the head of the radius and the capitellum of the distal humerus.
Presentation and Assessment
While most children will present with the classic history, as many as 33-49% of children may present without this classic history, with 22% of children in one series reporting a fall as the mechanism of injury.2,4 Reports in children younger than 6 months indicate that RHS may occur with a caretaker rolling a child over in a bed or crib.1 A child with RHS typically will present in the "nursemaid’s position," with the arm held in pronation and slight flexion at the child’s side.4 The child generally refuses to use the arm, and commonly may point to either the elbow or the distal forearm when asked where the arm hurts.
Most children do not exhibit tenderness or swelling of the elbow on palpation. The entire arm should be carefully palpated, focusing on the clavicle, the elbow, and the distal radius, as these commonly are fractured in children. The physician may need to use the parent to help calm the anxious child, or may even stand at a distance and observe while the parent palpates the affected extremity to identify any sites of tenderness. The child may resist supination, or may have pain with supination.
Radiography generally is reserved for children in whom the diagnosis is unclear, or in whom attempts at reduction fail. Children who exhibit little or no tenderness on exam and hold the arm in the nursemaid’s position do not require radiography prior to attempted reduction, whether or not the classic history has been described.5 If performed, radiographs usually are normal, and positioning for films often reduces the subluxation.2 Reports have identified displacement of the radiocapitellar line (a line drawn along the longitudinal axis of the radius which normally bisects the capitellum) in some children with RHS, however these radiographic changes resolved with reduction and were not found to alter treatment.6,7
The reduction of RHS usually can be performed without the aid of sedation and/or analgesia. The parent should be informed that while the reduction may be painful for the child, the pain is transient and the child likely will regain use of the arm quickly. The two methods of reduction most commonly described are the supination method and the pronation method.
Supination Method. The child is seated on the parent’s lap with the humerus held adducted to the child’s side by the parent. The physician then holds the child’s elbow with the thumb positioned over the child’s radial head. The thumb may be used to apply pressure to the radial head, but its main utility is to aid in the palpation of the "click" of reduction. The physician’s other hand is used to grasp the child’s wrist, and then to fully supinate the child’s forearm in a steady fashion. Once supinated, the elbow can be fully flexed or extended. The flexion maneuver is more common, and may be slightly more successful than extension.2
Pronation Method. The child is positioned in the same manner as when using the supination method. However, the forearm is grasped and rapidly hyper-pronated and fully flexed, once again using the thumb to help palpate the "click." This technique has been reported to be equally as effective as the supination technique in one recent trial,8 and superior in another.9
After Reduction Attempt. If a click is heard or palpated, the child almost always will regain use of the arm within 30 minutes.3 If no use of the arm occurs by 30 minutes, the physician should determine whether the child still holds the arm in the nursemaid’s position, and if supination remains painful. This suggests the need for further reduction attempts. Most reduction attempts in which a click is not detected will be unsuccessful,3 so repeated attempts should occur after 10 to 15 minutes of non-use. In Quan’s study, 53 out of 54 attempts in which a click was felt or heard were successful, as opposed to only 4 out of 13 in which no click was obtained. Approximately 30% of patients required two or more reduction attempts.3
If multiple attempts are unsuccessful, and the child has not regained use of the arm, one of two approaches can be taken. Sacchetti recommends that radiographs be performed at this time, looking for occult fracture.4 An alternate approach is to discharge the child with instructions to follow up in the ED in 24 hours, at which time radiographs may be performed if function has not returned spontaneously. Of 10 children in two case series released without return of function, six had spontaneous return of function in the intervening 24 hours before ED follow-up. The other four patients had return of function after repeated reduction attempts at the follow-up visit.2,3 If reduction is successful, analgesia, ED follow-up, and referral are unnecessary. However, parents should be aware that approximately 24% of children with RHS will have recurrent episodes.10
The value of elbow immobilization in children with RHS that cannot be reduced on the initial visit is unclear. However, if a child has repeated subluxation immediately after successful reduction, immobilization and referral may be necessary.7
RHS is a common diagnosis among young children presenting to the ED. While the classic history of longitudinal traction on the arm often is present, the diagnosis rarely is in doubt based on the combination of history and clinical assessment. Multiple reduction techniques are effective for RHS, and most children regain use of the arm with one or two reduction attempts. Among children with RHS that cannot be reduced, the physician must weigh the apparent reliability of the parent(s), the level of parental anxiety, and the level of physician comfort with the diagnosis of RHS when considering whether to order radiographs or to discharge the child with follow-up in 24 hours. Emergency physicians should be able to document painless use of the affected arm at the initial or follow-up visit to make a definitive diagnosis of resolved RHS and to rule out other pathology such as occult fracture, tumor, or infection.
Dr. Ufberg, Assistant Professor of Emergency Medicine, Assistant Residency Director, Department of Emergency Medicine, Temple University School of Medicine, Philadelphia, PA, is on the Editorial Board of Emergency Medicine Alert.
1. Newman J. "Nursemaid’s elbow" in infants 6 months and under. J Emerg Med 1985;2:403-404.
2. Schunk JE. Radial head subluxation: Epidemiology and treatment of 87 epidsodes. Ann Emerg Med 1990; 19:1019-1023.
3. Quan L, et al. The epidemiology and treatment of radial head subluxation. Am J Dis Child 1985;139: 1194-1197.
4. Sacchetti A, et al. Nonclassic history in children with radial head subluxations. J Emerg Med 1990;8: 151-153.
5. Macias CG, et al. History and radiographic findings associated with clinically suspected radial head subluxations. Ped Emerg Care 2000;16:22-25.
6. Snyder HS. Radiographic changes with radial head subluxation in children. J Emerg Med 1990;8:265-269.
7. Frumkin K. Nursemaid’s elbow: A radiographic demonstration. Ann Emerg Med 1985;14:690-693.
8. MacDonald J, et al. Radial head subluxation: Comparing two methods of reduction. Acad Emerg Med 1999;6: 715-718.
9. Macias CG, et al. A comparison of supination/flexion to hyperpronation in the reduction of radial head subluxations. Pediatrics 1998;102:e10.
10. Teach SJ, et al. Prospective study of recurrent radial head subluxation. Arch Ped Adol Med 1996;150: 164-166.