HPOCUS versus CBCT as a follow-up modality for patients with zygomatic arch fractures.

Handheld point-of-care ultrasound (HPOCUS) is a rapidly growing technology with an expanding range of medical applications. A new method to compare two-dimensional (2D) HPOCUS accuracy with three-dimensional (3D) cone-beam computed tomography (CBCT) was devised. Ten patients who had completed long-term follow up after surgical intervention to correct displaced zygomatic arch (ZA) fractures were included. The outer cortical outline of the 2D ZA was identified using HPOCUS and superimposed on to a 3D CBCT segmentation. A pointwise analysis of 100 discrete paired points was used to calculate the distance discrepancy between curves representing the ZA outlines derived from HPOCUS and CBCT. The mean (SD) distance between all patients' US and CBCT curves was 0.141 (0.087) mm. Given the minimal spatial discrepancy between the modalities, we recommend HPOCUS as the gold standard, first-line imaging follow-up modality for patients with ZA fractures.