Ultrasound Guided Closed Reduction of Depressed Zygomatic Arch Fractures

Overview

Zygomatic arch fractures have always been treated with blind closed reduction and is the most commonly used method. Blind reduction of fractures might lead to inadequate reduction and associated complications of facial asymmetry and limitations in mouth opening which may require reoperation for correction. Various methods like portable CT scan, C arm fluoroscopy, endoscopy and ultrasound have been proposed and used to visualize the reduction for better outcome. Out of these, ultrasound is inexpensive, easily available, easy to use, non-ionizing and has greatest potential to be used as standard for visual reduction of zygomatic arch fractures. There are studies where ultrasound has been compared to blind method and other modalities but level I evidence and recommended protocol for its intraoperative use has been lacking.

Isolated and depressed zygomatic arch fractures have an incidence of about 5 to 14% of lateral mid face fractures. Depressed zygomatic arch fractures have been managed by blind closed reduction historically based upon tactile sense of surgeon and auditory click assumed as the conclusive evidence of reduction. The minimal fracture exposure for zygomatic arch fractures either solitary or combined with zygomaticomaxillary complex fractures results in inadequate visibility of the fractures and inadequate or inappropriate reduction of fractures. These fractures can be visualized by surgical exposure with coronal approach but is limited by complications and extensive training required. Other options are intraoperative imaging with portable CT scan but they are cumbersome, require radiologists for positioning and are not available in all operative units as well as expensive. Endoscopic visualization and reduction are another option for intraoperative control of these fractures but endoscopes are expensive, not available in all operative units and require experience and training to use appropriately. Various studies and our own experience show that unacceptable number of depressed zygomatic arch fractures remain incompletely reduced with blind reduction method. The resulting deficit might be as small as a depressed lateral face, inadequate sagittal projection of cheek to inadequate mouth opening. Portable ultrasound machines are readily available in almost all anesthesia units and operating rooms. These ultrasound units can be utilized to reduce the zygomatic arch satisfactorily with real time image guidance and it has advantage of being radiation free and inexpensive compared to fluoroscopy based portable C arm units. A small pilot in our own unit has shown remarkable difference between reduction achieved under ultrasonography guidance vs closed reduction based on tactility. This method should be explored and perfected to bring in common use among Oral \& Maxillofacial surgeons so that blind assumption of fracture reduction is replaced by a more scientific confirmation of fracture reduction.