Utility of fast MRIs in pediatric elbow injuries

Abstract

ABSTRACT: Background: Pediatric elbow trauma presents a diagnostic challenge for clinicians. Radiographs may be insufficient in assessing the radiocapitellar alignment and advanced imaging or invasive procedures such as an intraoperative arthrogram may be indicated. The purpose of this study is to describe the application and utility of fast magnetic resonance imaging (MRI) in the diagnosis and management of traumatic elbow injuries in pediatric patients. Methods: We reviewed pediatric patients who underwent a fast MRI of the elbow between 2014 and 2022. A fast MRI was defined as an MRI using rapid sequences accelerated conventional sequences, or fewer conventional sequences than a standard exam. Imaging for chronic or nontraumatic injuries was excluded. We identified patient demographics, MRI scan times, and clinical course. Results: Twenty-three patients (8 females and 15 males) with fast elbow MRI scans were identified. The mean age was 5 years (range 2-12 years, SD 2 years). All patients had radiographs and 4 had CT scans prior to MRI. The average scanning time was 14 minutes (SD 6 minutes). Only one patient required anesthesia. Twenty of the 23 patients had a fracture identified on elbow radiographs and 8 were Monteggia fracture-dislocations. Nine of these patients demonstrated subluxation of the radiocapitellar joint requiring operative management in 8 patients, and one additional patient underwent surgery for displaced radial neck fracture. Three patients sustained an elbow dislocation without fracture identified on radiographs; of these, one had persistent radiocapitellar subluxation on MRI requiring surgical management. A total of 13 patients (56.5%) did not require operative management based on fast MRI findings. Outcome data were available for 22 patients with a mean follow-up was 23.6 months. One patient had residual pain and 8 had some range of motion limitation at the final follow-up. All patients had reduced elbow joints on follow-up radiographs. Conclusions: Fast MRIs can assist with the clinical evaluation of acute elbow injury in pediatric patients with equivocal radiographic findings and particularly in those with possible radiocapitellar subluxation/dislocation. This novel imaging technique has the potential to change clinical management, decrease the need for unnecessary procedures, and prevent complications of missed injuries. Key Concepts: (1) Fast MRIs allow for high-resolution imaging of structures in skeletally immature patients without the need for ionizing radiation and anesthesia. (2) Radiographs alone may be insufficient for identifying radiocapitellar subluxation in pediatric patients. (3) Confirmation of anatomic alignment with fast MRI can obviate the need for invasive procedures such as joint arthrogram in patients who sustain traumatic elbow injuries. Level of Evidence: IV

Keywords

• Fast MRI
• Pediatric trauma
• Monteggia fracture
• Elbow fracture
• Elbow subluxation