Retrospective analysis of external pin fixation of mandibular fractures: A 25-year single institution experience

External fixation of mandible fractures is an infrequently utilized fixation treatment modality in comparison to open reduction internal fixation (ORIF) or closed reduction techniques. However, external fixation still provides a necessary modality in the management of select mandibular fractures. Therefore, we aim to draw trends, outcomes, and treatment timelines through a retrospective analysis to better guide, advise and predict realistic treatment outcomes in the future for our patients. This abstract shows trends in indications, complications, airway management and timeline to definitive reconstruction through the experience of a single institution (University Hospital, Newark, NJ) over a period of 25 years. IRB approval was obtained from Rutgers University and University Hospital, Newark, NJ. Twenty-nine instances of external fixation of mandible fractures were found over 25 years. The charts, imaging, and notes were individually reviewed. The data points collected included age of the patient at time of injury, etiology of injury, duration of external fixation, numbers of Schanz screws, type of extraoral connecting bar, airway management, time to reconstruction, type of reconstruction, type of bone graft used, incidence of multiple space infections, and complications. The duration of study was from 1997 - 2023. The patients were found using CPT codes 21452 (percutaneous treatment of mandibular fracture, with external fixation) and 21454 (open treatment of mandibular fracture with external fixation). Twenty-nine instances of external fixation were found, 28 of the 29 had extensive documentation about the surgery and post operative period. The average age at the time of injury was 37 years old, 2 females and 26 males. 5 different types of etiologies were found. 14 gunshot wounds, 3 motor vehicle collisions (MVCs), 6 osteomyelitis with nonunion from a previous ORIF management of a mandible fracture, 4 pathologic fractures and 1 patient with a one-week-old unrepaired open fracture that developed a significant deep neck infection. The average duration of the external fixator was 88 days, ranging from 18 - 291 days. 10 patients were electively intubated and extubated for the external fixator surgery. 15 patients underwent tracheostomy due to airway compromise or expected prolonged intubation. The most common number of Schanz screws placed were 4, with a range of 4-6. The most common stabilizing system used to connect the screws were carbon fiber rods (61%). Prior to 2008, pre-adapted titanium was never used, after 2008 it was used in more than half of the cases. The most common complication was infection, occurring in 4 cases. With regards to secondary reconstruction, 55% of the cases required autologous harvesting of the anterior iliac crest. In summary, our research showed the average duration of external fixation duration to be dependent on the mechanism of injury. Failure of previous ORIF with non-union and concomitant osteomyelitis had an average external fixation duration of 107 days. Gunshot wounds had an average external fixation duration of 79 days. Motor vehicle accidents had an average external fixation duration of 18 days. Pathologic fractures had an average external fixation duration of 16 days. The most common complication was infection, occurring in 4 (14%) cases. For airway management, 100% of GSW injuries received tracheostomy, 66.7% of MVCs, 14% of osteomyelitis status-post prior ORIF, and no patients with pathologic fractures associated with malignancy received tracheostomy. This research aims to consolidate 25 years' worth of surgical experience and patterns for external fixation to better guide, advise and predict realistic treatment outcomes.