1.
Introduction
Gunshot wounds
to the head and neck are complex injuries that pose a unique challenge to
healthcare providers. Mandibular injury secondary to gunshot wounds
occursfrequently [6]. Presentations of these
injuries are highly variable and multiple treatment techniques have been
described in the literature[7,8].Historically,
closed reconstructive techniquesincluding Maxilla-Mandibular Fixation (MMF) and
external fixation were often preferred. Itistheorized that by avoiding periosteal
stripping and minimizing osseous devitalization, blood supply to the bone would
be optimized[2,9-11].However, with the
advancement of biocompatible titaniumplating systemsand surgical techniques,
open reduction of the fracture with rigid internal fixation has become a widely
used treatment modality[7,12-15].
Thepurpose of
this study is to examine outcomes of all patients who were treated for
mandibular gunshot wounds at the Virginia Commonwealth University Medical
Center. We focused our study on fracture characterization, treatment method,
and associated complications.
2.
Methods
We performed a
retrospective review at the Virginia Commonwealth University Medical Center for
all patients who have sustained gunshot wounds to the mandible from February 1991
through December 2012. Using a computerized search based on ICD-9 code,
105patients were identified in the trauma registry. Patients were treated by
the plastic and reconstructive surgery, otolaryngology, and oral-maxillofacial
surgery services.Individual chart review was performed anddemographic
information (gender and age) and fracture location (angle,body, and symphysis/parasymphysis)
were recorded. Specific emphasis was placed on identifying all treatment
regimens, follow-up periods, and associated complications. Treatment options
included conservative management, MMF, external fixation, and Open Reduction and
External Fixation (ORIF). For outcome analysis, inclusion criteria included a
minimum follow-up period of 4 weeks. Associated complications were categorized
into major and minor complication groups.
3.
Results
The initial
database search identified 105 patients with mandible fractures secondaryto
gunshot wounds. 33 patients with insufficient documentation and 5 patients who
expired from other injuries were excluded from the study. Analysis of the
remaining 67 patients yielded a mean patient age of 30.8 years (range, 15 - 71
years), with a majority (58 patients, 86.6%) being male.
57 had
associated Cause E codes (ICD-9-CM)available. 41 injuries (72%) were caused by
an assault by handgun (965.0), shotgun (965.1), or other unspecified firearm
(965.4). Twelve injuries (21%) were caused by self-inflicted wounds by handgun
(955.0), shotgun (955.1), unspecified firearm (955.4), or firearms and
explosives (955.9). Two injuries (3.5%) were caused by accident by handgun
(922.0), or an unspecified firearm missile (922.9). Lastly, the remaining two
injuries (3.5%) were caused by handgun (985.0) or shotgun (985.1) undetermined
whether accidentally or purposely inflicted.
Twenty-six
patients presented with Multiple Mandibular Fractures (40.3%). The distribution
of the mandibular fractures can be seen in (Figure 1).
The most commonly affected region was the mandibular angle (44 fractures,
43.4%), followed by the mandibular body (36 fractures, 36.3%), and
symphyseal/parasymphyseal (20 fractures, 20%).
Of the 67
patients, 7 underwent conservative treatment. Surgical repair for the remaining
60 patients is depicted in (Figure 2).
24patients (40%) underwent MMF. Of these 24 patients, 2patients were also
fitted with external fixators. 3patients (5%) were treated with external
fixation alone. The remaining 33 patients (55%) underwent ORIF with rigid
plating systems. 21 of these patients who were placed in ORIF were also placed,
either initially or simultaneously, in MMF or external fixation. 2 patients
were also treated with a vascularized free fibula graft. Follow up for these patients were not
sufficient to comment on their postoperative outcomes. Additionally,11patients
were treated with an iliac crest bone graft.1 out of the 11 became infected and
was replaced by an osteocutaneous distal radial free flap. The bone graft was
performed in 2009 and the radial free flap was performed in 2011. The patient
was followed for 2 years post operatively and there were no complications
during that time.
Complications
were evaluated in 50 patients who had a minimum follow-up time of 4 weeks. The
medianfollow-up time was 18 weeks and ranged from 4 weeks to 530 weeks. From
this group, 15 patients experienced post-operativecomplications and 5 of these
patients experienced multiple complications. A total of 20 complications were
identified (19 major and 1 minor complication). Major complications included
infected hardware, infection requiring incision and drainage, non-union,
malocclusion, and extrusion of hardware.Minor complications included issues
that were managed in an outpatient setting (infection treated with oral
antibiotics, seroma, etc.). A summary of all identified complications is
provided in (Table 1).
Of the 11
patients who received bone grafts, 6 patientsinitially underwent ORIF without
external fixation and need for bone graft was deemed a result of complications
from the primary surgery: 2 patients of the 6 complications that had bone
grafting were secondary to mandibular defects one performed in 2003 and the
other in 2004, 1 was from chronic osteomyelitis performed in 2009, 1 was to
fill a soft tissue and bone defectperformed in 1993, 1 was from exposed
hardware performed in 2007, and 1 was to repair a continuity defect performed
in 2004. The other 5 patients who had bone grafting, were performed on patients
that had external fixation devices. Bone grafting in these individuals were not
categorized as procedures secondary to complications.
External
fixation, with or without MMF or ORIF, had a complication rate of 50%. 1 case
had a seroma that was drained in office, 2 cases had abscesses that required
intraoperative incision and drainage, and 1 had hardware exposure. The rates of
major complication for ORIF and ORIF with MMF are 33% and 38%, respectively.
MMF alone had a major complication rate of 4.5% (1 out of 22 patients), which
an infection secondary to a fistula formation that required I&D.
4.
Discussion
While firearm
injuries involving the mandible are an uncommon cause of mandible fractures,
the resultantinjuries are some of the most devastating[16].Mandibular
fractures resulting from firearms are highly destructive injuries often
characterized by multiple fractures, comminuted fractures, and large areas of
missing bone[1,2,17]. Fracture patterns based on
gunshot wounds to the mandible have been previously described.Most published
studies have noted a higher incidence of fractures located in the
symphysis/parasymphysis region overall, with gunshot wounds mainly occurring in
the mandibular body[18]. Our series noted a
similar fracture pattern secondary to mandibular gunshot wounds, which mainly
occurred in the body and angle(Figure 3).
Treatment and
reconstructive options must be tailored to the specific needs of the population
served. This variability inadvertently provides an increased number of
treatment and reconstructive options in dealing with mandibular gunshot wounds.
Overall, management of firearminjuries to the mandible has evolved over the
last 50 years and although rigid internal fixation techniques have become more
widely utilized, a definitive consensus on treatmenton fractures secondary to
gunshots has yet to be elucidated[1,5,12].
The use of ORIF
in the treatment of gunshot wounds to the mandible has advantages as well as
disadvantages over the use of MMF. ORIF remains a viable treatment option for
patients with minimally displaced fractures and localized area of comminution[12]. Advantages include: significantly shortened
treatment course, quicker return to function, potential for better oral hygiene
and nutrition,often single-stage definitive treatment, and direct visualization
of bone fragments allowing better anatomic reduction[1,3,4,19-21].
Benefits of MMF with or without external fixation are that it provides
stabilization of a fracture without the risk of disrupting the vascular supply
to the fracture, is most cost effective, and has less risk of postoperative
infection[3,4,16,21].
We do not have
adequate numbers of patients undergoing free tissue transferor external
fixation to draw meaningful conclusions from these groups. Studies have shown
that these have been well established options for reconstruction in the setting
of mandibular traumawith large enough defects requiring free tissue transfer[22].Complications in patients who underwent bone
grafts to those who did not have bone grafting is revealing. In our study, bone
grafting was reserved for reconstructing previously performed ORIF that had a
complication in 55% of cases (6 out of 11). The other 45% (5 out of 11) cases
that underwent bone grafting were planned procedures.
The results of
our study show that the complication rate for patients who are treated
surgically remains high. In our study, our overall complication rate of 40% is
similar to previous reports in the literature[1,5].
External fixation, with or without MMF or ORIF, had a complication rate of
50%.The rates of major complication for ORIF and ORIF with MMF are 33% and 38%,
respectively[23]. MMF alone had a major
complication rate of 4.5%. The most likely reason that patientswho underwent
external fixation suffered higher complication rates was not necessarily the
use of external fixation itself, but nature of their complex injury. External
fixation is reserved for fracture patterns that are unable to be reduced with
either closed reduction or ORIF[24].
Our study is a
retrospective review in which the cases hadvariable clinical presentation and
different operative surgeons under different specialties. This makes it
difficult to elucidatea meaningful relationship between treatment modalities
and their direct causality in complication rates.Previous studies have
suggested a positive correlationbetween the severity of the injury and the
complications after treatment[1,24].
A limitation to
this study would be the patient population who suffer from gunshot wounds. Our
study did not compare the rates of uninsured or noncompliance and how it could
affect the rates of complication.Other studies have compared these factors in
trauma and specifically gunshot wound patients. Most patients in this
population are uninsured[24]. Also, to this
date, there is no literature comparing post-operative compliance in this
patient population. This may be representative of the complexity in treating
this patient population. There are many factors that work congruently in
affecting outcomes. While higher complication rates and in some cases death
tends to be associated with trauma patients that are uninsured, this is an
association not necessarily a cause.
5.
Conclusion
Our study shows
the varied management of traumatic gunshot wounds to the mandible over the
past21 years at an urban trauma center. Although the overall complication rates
are similar to literature already published, it is not without caveats. The
number of surgeons who operated on the 60 patients varied from different surgical
services. Also, out of the patients treated with ORIF 21 out of the 33 patients
(64%) were treated in conjunction with MMF thus clouding the differentiation of
complications from ORIF versus MMF alone. These factors make it difficult to
ascertain the exact causes of surgical complications postoperatively.
As noted in the
discussion, external fixation with or without MMF or ORIF had an extremely high
complication rate. This may be attributed to the complexity of the injury
itself and not necessarily the use of the external fixation device. This same
conclusion could be drawn in comparison to major complication rates among ORIF,
ORIF with MMF, and MMF alone where MMF alone had the lowest complication rate
and patients that received ORIF had a higher complication rate.
Gunshot
woundsremain a rare cause of mandibular trauma. Determining a consensus on
approaches to treatment of gunshot wounds to the mandible remains elusive.Our
study shows a wide variety of treatment methods and modalities. It relies heavily
on surgeon preference andtraining. Further prospective studies will be needed
to fully establish a standard of care for treatment of mandibular injury
secondary to gunshot wounds. Due to the wide variety of traumatic injuries and
treatment options for gunshot wounds to the mandible, this may prove to be
difficult. Ultimately, the choice of reconstructive technique is based on the
patient presentation, fracture characterization, and surgeon experience.
research article 
