Do all patients with shoulder dislocations need prereduction x-rays?

Some would advocate against routine use of prereduction x-rays for shoulder dislocations. Our objective was to examine the percent of dislocations that also had fractures as a function of age to determine whether there are some decades of life with a sufficiently low risk of fracture to avoid routine prereduction x-rays.

This was a retrospective cohort study in 19 New Jersey and New York emergency departments. We used The International Classification of Diseases, 9th Revision, Clinical Modification (ICD-9) codes to identify patients with shoulder dislocations and, among these, those who also had fractures. A priori, we chose to group the patients by decade of life. For patients with dislocations in each age group, we calculated the percent that also had fractures.

Of the total 5,408,837 visits in the database, there were 7209 patients with dislocations, of which 465 (6.5%) had fractures. We found the lowest percent of fractures in the 2nd and 3rd decades of life (0.7% [95% confidence interval, 0.3%-1.2%] and 0.8% [0.4%-1.3%]). In the 4th and 5th decades of life, the percents were 2.6% (1.7%-3.5%) and 4.6% (3.2-6.0%), respectively, and they steadily increased to 19% or greater in the 8th to 10th decades of life. Omitting the prereduction x-rays for patients in the 2nd and 3rd decades of life would reduce the total number of prereduction x-rays by 40%.

In the second and third decades of life, less than 1% of patients with shoulder dislocations also had fractures. Because these patients have a sufficiently low risk of fracture, routine prereduction x-rays may not be necessary for them.