Radiographic changes with radial head subluxation in children.

Radial head subluxation (RHS) produces no radiographic abnormalities according to most experts. However, recent anecdotal case reports have identified displacement of the radiocapitellar line (RCL) in pediatric patients with RHS. To verify this finding, we retrospectively reviewed all patients less than 5 years of age who received elbow and forearm radiographs in our emergency department. From January 1988 through April 1989, we identified 20 cases of RHS. Of the 20 radiographs, 5 (25%) were read by the attending radiologist as abnormal due to RCL displacement indicating subluxation of the radiocapitellar articulation. All 5 of these radiographs had RCL displacement greater than 3 mm. The remaining normal radiographs had RCL displacement less than or equal to 3 mm. The presence of RCL displacement without disruption of the radiocapitellar articulation confirms the diagnosis of RHS, but does not appear to change treatment or outcome in this subset of patients. In addition, radiographs may not be mandatory when the diagnosis of RHS is certain. We suggest obtaining radiographs if the history (i.e., fall) or physical examination is atypical or if reduction is unsuccessful to rule out more serious injuries such as radial head dislocation or fracture.