Nursemaid's elbow-also referred to as annular ligament displacement (Kaplan & Lillis, 2002), pulled elbow, or radial head subluxation-is a partial or an incomplete dislocation of the elbow most often caused by a sudden pull on the extended pronated arm, such as in the case of a child who stumbles while being led by the hand by an adult or by a parent tugging on an uncooperative child. The injury has been described as a slipping of the radial head distally beneath the annular ligament (Karasick, Hunter, & Taljanovic, 2004), although Kaplan and Lillis (2002) noted that the radial head does not move out of its position relative to the capitulum; rather, there is a dislocation of the annular ligament between the capitulum of the distal humerus. The anatomy and pathology of the elbow are described in detail elsewhere (Boyette & London, 1948; Kaplan & Lillis, 2002; Miyasaka, 1999).
Nursemaid's elbow is a common reason for an emergency department (ED) visit, although the epidemiology of the condition is not well described. A 1948 study by Boyette and London (1948) cited an estimate of 1% of surgical cases in children younger than 9 years. In a study of injury-related ED visits occurring during 1 year among District of Columbia residents aged younger than 3 years, Brenner et al. (2002) found that nursemaid's elbow accounted for 3.5% of all injury-related ED visits and had an incidence rate of 5 per 1,000 person-years. In a study of 501 cases of radial head subluxation in 427 children (mean age, 2.4 years; range, 22 days-9.7 years) presenting to a tertiary care pediatric ED over a 2-year period in Canada, Toupin, Osmond, Correll, and Plint (2007) reported a median time of 1.3 hr from triage to physician assessment. I have described the occurrence of U.S. ED visits for nursemaid's elbow during 2005-2006 by using the data from the National Hospital Ambulatory Medical Care Survey (NHAMCS).
The NHAMCS is a national probability sample survey conducted by the National Center for Health Statistics of the Centers for Disease Control and Prevention in conjunction with the U.S. Census Bureau. The survey captures ambulatory care visits to EDs that operate 24 hr per day in nonfederal short-stay or general hospitals. For each patient visit (i.e., the sampling unit for NHAMCS), trained hospital staff complete a brief, one-page patient form. Detailed methods of the survey are described elsewhere (McCaig & McLemore, 1994). A total of 33,605 patient forms were provided by 367 participating EDs (hospital sampling response rate, 89.6%) in the 2005 NHAMCS, which was conducted between December 27, 2004, and December 25, 2005. The 2006 NHAMCS was conducted between January 2, 2006, and December 31, 2006, and collected data on 35,849 patient visits to 389 EDs (hospital sampling response rate, 90.7%). To obtain national estimates, each record is assigned an inflation factor or a patient visit weight. The estimated number of visits made by all patients to EDs in the United States can then be obtained by aggregating patient visit weights.
Emergency department records were searched for a physician's primary discharge diagnosis, coded according to the International Classification of Diseases, 9th Revision, Clinical Modification (ICD-9-CM), of closed dislocation of the elbow (ICD-9-CM, 832.0x). Records were excluded for patients aged 18 years or older. Rates of nursemaid's elbow visits for 2005-2006 were computed using the weighted number of such visits as the numerator and midyear population estimates of the civilian, noninstitutionalized U.S. population, averaged for 2005 and 2006, as the denominator. All analyses were completed using SAS, Version 9 (Cary, NC), and SUDAAN, Version 9 (Research Triangle Park, NC).
During 2005, there were an estimated 115,323,000 ED visits (for all causes), of which 28,915,000 were for youth (<18 years); similarly, during 2006 there were 119,192,000 ED visits, of which 26,310,000 were for youth. Of the 55,225,000 ED visits made for youth, 37% were injury related. During 2005-2006, an estimated 199,000 ED visits were for youth for nursemaid's elbow (1% of injury-related ED visits by youth), or 27.0 per 10,000 population (see Table 1). ED visits were more common among girls than among boys (1.5:1), and the majority (69%) of visits occurred among youth who were 1 or 2 years of age (see Table 1). Three-quarters (77%) of visits included observation by a physician with an average wait time of 52 min (95% confidence interval, CI, 37-68 min); the overall average length of ED visits for nursemaid's elbow was 108 min (95% CI, 80-137 min). An x-ray image was ordered for 56% (95% CI, 39%-72%) of ED visits.
It is important to note that while these data are representative of ED visits in the United States, the occurrence of injuries treated in other clinical settings, at home, or those treated in settings such as at athletic or at educational venues are not included. In addition, this brief note was not able to examine visits for recurrent nursemaid's elbow, a common problem for radial head subluxation.
Nursemaid's elbow is readily treated by healthcare professionals with resolution by supination of the forearm, which allows the ligament to be restored to its original position (Della-Giustina & Della-Giustina, 1999). Correction and reduction of the subluxation are described in detail elsewhere (Boyette & London, 1948; Kaplan & Lillis, 2002). Perhaps more importantly, nursemaid's elbow is a preventable condition. As nursemaid's elbow is often caused by a sudden pull of a child in a different direction than the child is moving, parent and caregiver education is potentially an effective form of prevention of nursemaid's elbow and related healthcare utilization. Pediatricians, nurses, and midwives have an important role in highlighting for parents the potential harm that may result from actions such as picking up a child by one arm after a fall, pulling a child out from under a table, helping a child across the street and up the curb, or tugging on an uncooperative child (Boyette & London, 1948). Given that healthcare resources are limited and EDs are often plagued by overcrowding, further research is needed to examine issues of cost-effectiveness of treatment setting options, including primary prevention. At present, the cost-effectiveness of treating nursemaid's elbow in the ED versus a pediatrician's office versus over-the-phone consultation (Kaplan & Lillis, 2002) versus the costs of primary prevention including caregiver education and so forth are unknown.
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