Early Ultrasound Follow-Up of Extension-Type Supracondylar Fractures Treated by the Collar-and-Cuff (Blount) Technique

BACKGROUND: Extension-type supracondylar fractures can be treated with external immobilization, with the elbow flexed 100 degrees . However, this technique requires early evaluation by true lateral x-ray of the elbow to detect secondary fracture displacement. QUESTIONS/PURPOSE: The purpose of this work is to evaluate whether ultrasound imaging is suitable for demonstrating initial reduction of supracondylar fractures and early secondary displacement of the fracture. METHODS: Fourteen patients aged 3 to 7 years (mean, 4.8 years) were treated by closed reduction under general anesthesia and immobilization with a collar and cuff. All patients had early postoperative x-rays and ultrasonography on day 1, as well as day 8 x-rays and ultrasonography. Ultrasonograms were performed by an experienced senior radiologist. RESULTS: In all cases, a complete reduction was confirmed at initial follow-up on both sonogram and intraoperative fluoroscopy. In 13 of 14 cases, no secondary displacement of the fracture was noted at day 8 on either ultrasonography or x-ray images. In 1 case, a secondary displacement was noted at day 8 on ultrasonography and confirmed by the lateral x-ray. CONCLUSIONS: Our study found a complete agreement assessing the quality of intraoperative reduction of supracondylar fractures by radiographs and ultrasonography. These results confirm that ultrasound imaging is suitable for demonstrating secondary displacements of supracondylar fractures in children. We postulate that in Gartland types II and III fractures treated by Blount procedure, a negative ultrasound result at day 8 follow-up may reduce the need for further radiographs. However, in any doubtful situation, the need for conventional radiographs remains. LEVEL OF EVIDENCE: Diagnostic study, level II.