Treatment of sagittal fracture of the zygomatic arch root assisted by surgical navigation technology

Published ahead of print: Treatment of Sagittal Fracture of the Zygomatic Arch Root Assisted by Surgical Navigation Technology, by Dai et al. Journal of Craniofacial Surgery (2018).


Sagittal fracture at the temporal root of the zygomatic arch often occurs as a part of zygomaticomaxillary fractures. The authors described the application of computer-assisted navigation in the lag screw insertion for the fixation of sagittal fracture at the temporal root of zygomatic arch. Using the presurgical planning of the computer-assisted navigation system, the trajectory of lag screw insertion was designed, and the insertion depth was calculated. In the presurgical planning, the trajectory of screw insertion was placed with an anterior inclination of 10° to 15° (mean: 12.24°), and the screw insertion depth was 9.0 to 12.0 mm (mean: 10.65 mm). In the operation, the screw insertion in the fixation of the sagittal fracture was performed under the guidance of navigation system according to the presurgical planning. The postoperative CT scan showed exact reduction and fixation of the sagittal fracture in all cases. Computer-assisted navigation is a useful tool for the lag screw insertion in the precise fixation of sagittal fracture at the temporal root of the zygomatic arch in complex zygomaticomaxillary fractures.

(A) In the presurgical planning, the entry point (red point) and trajectory of screw insertion (red line) were designed in the mirrored zygomatic arch root, and the calculated screw insertion depth (yellow line) was 10.1mm in this case. (B) Registered surgical motor used for screw hole drilling. (C) The sagittal fractures at the zygomatic arch root. (D) Screw hole drilling according to presurgical planning under computer-assisted navigation, and the long axis of drill (yellow line) coincided with the designed trajectory (red line) in the axial, sagittal, and coronal planes. (E) Screw hole drilling performed with guidance of the computer-assisted navigation system.

AR for extremity reconstruction surgery using 3D vascular models with perforating vessels


Open Access article Through the HoloLens™ looking glass: augmented reality for extremity reconstruction surgery using 3D vascular models with perforating vessels by Pratt et al. in European Radiology Experimental 2018 2:2.

Workflow diagram showing the processes involved in AR content productio


Precision and planning are key to reconstructive surgery. Augmented reality (AR) can bring the information within preoperative computed tomography angiography (CTA) imaging to life, allowing the surgeon to ‘see through’ the patient’s skin and appreciate the underlying anatomy without making a single incision. This work has demonstrated that AR can assist the accurate identification, dissection and execution of vascular pedunculated flaps during reconstructive surgery. Separate volumes of osseous, vascular, skin, soft tissue structures and relevant vascular perforators were delineated from preoperative CTA scans to generate three-dimensional images using two complementary segmentation software packages. These were converted to polygonal models and rendered by means of a custom application within the HoloLens™ stereo head-mounted display. Intraoperatively, the models were registered manually to their respective subjects by the operating surgeon using a combination of tracked hand gestures and voice commands; AR was used to aid navigation and accurate dissection. Identification of the subsurface location of vascular perforators through AR overlay was compared to the positions obtained by audible Doppler ultrasound. Through a preliminary HoloLens-assisted case series, the operating surgeon was able to demonstrate precise and efficient localisation of perforating vessels.

a. Case 5 CTA imaging showing the location of perforating arteries with yellow arrows. b. Case 2 example HoloLens rendering of segmented polygonal models

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