A Comparison of Two Techniques in the Reduction of Radial Head Subluxation

ABSTRACT & COMMENTARY

Source: Macias CG, et al. A comparison of supination/flexion to hyperpronation in the reduction of radial head subluxations. Pediatrics 1998;102:e10. URL: http://www.pediatrics.org/cgi/content/full/102/1/e10.

Radial head subluxation (rhs), more commonly known as nursemaid’s elbow, is a frequent upper extremity injury seen in the emergency department (ED). The traditional technique used in reduction involves supination at the wrist followed by flexion at the elbow. This prospective study attempts to compare two maneuvers: the traditional method with that of hyperpronation at the wrist. Children younger than 6 years of age, presenting to two urban pediatric EDs and two suburban pediatric ambulatory care centers with a diagnosis of RHS, were randomized to either group. After initial reduction, a second attempt was made if no return of function was observed within 15 minutes. The alternate method was used if the second attempt failed after 15 minutes of observation. Of the 90 patients enrolled, five had a final diagnosis of fracture and had to be removed from the study. Of the 41 patients included in the hyperpronation group, 39 (95%) were successfully reduced on the first attempt. The remaining two required a second attempt. However, only 34 (77%) of the 44 patients in the supination group were successful on the first attempt. The remaining 10 patients required a second attempt, of which six patients needed to crossover to the hyperpronation group. Of these, five were reduced in the first attempt of hyperpronation and one was reduced on the second attempt. One patient failed both techniques.

Comment by Raemma Paredes, MD

The current theory in the development of RHS is that the annular ligament, which holds the radial head in place between the proximal ulna and distal humerus, becomes trapped in the radiocapitellar joint. This occurs when a longitudinal traction force is applied to the wrist or hand with the elbow in extension and the forearm in pronation.1 Recent studies, including this one, have shown that a history of a pull is obtained only half the time, while a history of a fall on the elbow is obtained in about 20%.2 Maneuvers such as supination of the forearm and hyperextension of the elbow work as well.2 Macias and associates did not attempt to explain how hyperpronation could bring the annular ligament back in place. Is there, perhaps, more than one explanation for the development of RHS?

This study reinforces the practice of getting radiographs if multiple attempts at reduction are unsuccessful. Five patients had radiographic evidence of a fracture. Because of the high recurrence rate found in the study (32.9%), and those in other studies (23.7-37%),2-4 it is important for clinicians to counsel caretakers about this. In a child with recurrent subluxations and a reliable caretaker, hyperpronation at the wrist may be a simple maneuver to teach.

Macias et al should be congratulated for a well-designed and practical study. This study showed that the hyperpronation technique is definitely more successful than the traditional method of radial head reduction. It is also easier to do and less frightening to the patient and the parent. The clinician has more options in the management of RHS. (Dr. Paredes is an attending in Pediatric Emergency Medicine, Temple University Hospital, Philadelphia, PA.)

References

1. Young GM. Reduction of common joint dislocations and subluxations. In: Henretig FH, et al, eds. Textbook of Pediatric Emergency Procedures. Baltimore: William and Wilkins; 1997:1075-1104.

2. Schunk JE. Radial head subluxation: Epidemiology and treatment of 87 episodes. Ann Emerg Med 1990; 19:1019-1023.

3. Schutzman SA, Teach S. Upper-extremity impairment in young children. Ann Emerg Med 1995;26:474-479.

4. Quan L, Marcuse EK. The epidemiology and treatment of radial head subluxation. Am J Dis Child 1985;139: 1194-1197.