Locked Bridge Plating is a Suitable Option for Forearm Fractures Secondary to Civilian Low Velocity Gunshot Injuries

Introduction: The purpose of this retrospective study is to compare the outcomes of low velocity gunshot fractures of the forearm treated with minimal debridement and locked bridge plating to patients treated with formal debridement and conventional plating. Materials and Methods: A 10 year IRB approved retrospective review of our national trauma database was conducted. Initial treatment consisted of wound care and sterile dressing. Forearm radiographs were acquired to determine bony involvement. All patients received intravenous antibiotics upon presentation to the emergency department and for a minimum of forty-eight hours after admission or operative intervention. Patients were placed into two categories of operative or nonoperative treatment. Those placed into operative treatment were further divided into the subcategories of formal debridement and plating or minimal debridement and plating. Results: 94 patients were included in the study. 29 were treated nonoperatively and 65 were treated operatively. Of those 65, 30 underwent minimal debridement and bridge plating and 35 were treated with formal debridement and bridge plating. All patient radiographs displayed fracture healing at latest follow-up with no evidence of infection or osteomyelitis. Nerve injuries were found among 15 patients and vascular injuries were present in 7. Conclusions: Both methods of irrigation and debridement resulted in reliable osseous union with no instances of osteomyelitis. These results suggest that immediate locked bridge plating with minimal debridement is a suitable option for the treatment of forearm fractures following low velocity gunshot injuries.


Introduction
There are 300,000 injuries and 30,000 hospitalizations from gunshot wounds annually in the United States [1][2][3] primarily from low-velocity handguns. These weapons produce less soft-tissue injury than high-velocity rifles or shotguns attributed to lower mass, velocity and energy transfer of the projectiles to surrounding tissues [4,5]. Gunshot wounds of the forearm have been reported in several small series in the literature; however, no treatment guidelines backed by adequate scientific evidence exist. Prior studies with limited numbers have recommended debridement irrigation, antibiotics and compression plating for displaced fractures of one or both bones, and immobilization for undisplaced simple fractures of single bones. We feel that aggressive debridement and conventional compression plating may not be practical for these injuries which often have boney comminution but minimal soft tissue injury. A potential alternative is limited debridement and bridge plating. The purpose of this study is to compare the outcomes of low velocity gunshot fractures of the forearm treated with minimal debridement and locked bridge plating to patients treated with formal debridement and conventional plating.

Materials and Methods
An IRB approved 10-year retrospective review of our hospital trauma database revealed one-hundred and one patient admitted to the hospital with forearm fractures following gunshot wound (2000)(2001)(2002)(2003)(2004)(2005)(2006)(2007)(2008)(2009)(2010). Seven patients were excluded from the study as their injuries were the result of a high-velocity firearm, leaving ninety-four patients treated for gunshot wounds of the forearm with hospitalization. Patients who were discharged from the emergency room with gunshot wounds with or without fractures and patients who left the hospital against medical advice prior to treatment were not captured in this database. There were eightythree males and eleven females. The average age was 27.7 years with a range of 16-52 years. The average duration of follow-up of all patients was 27.3 months with a range of 9 to 105 months.
Treatment was initiated with wound care by applying a sterile dressing in the emergency department. Forearm radiographs were acquired to determine bony involvement. Clinical suspicion of limb ischemia by physical exam was an indication for angiography. All patients received intravenous antibiotics upon presentation to the emergency department and for a minimum of forty-eight hours after admission or operative intervention. The initial antibiotic selected was cefazolin with or without gentamicin, and some patients with

Operative Treatment
Sixty-five patients were treated operatively. Thirty patients

Nerve Injuries
There were fifteen patients with an associated nerve injury. The ulnar and median nerve were the most common nerves injured (six

Vascular Injury
Seven patients presented with signs of associated vascular injury of the forearm. There were four radial artery injuries and four ulnar artery injuries. One patient had both arteries injured and repaired. All patients had a viable limb on follow up. Three patients had nerve injury associated with vascular injury. One patient developed a compartment syndrome requiring fasciotomy.

Discussion
Early stabilization of forearm fractures is important after a gunshot injury and the management of the open wound and soft tissue injury is always an important consideration for surgical planning. In this study, we showed that minimal irrigation and debridement of the entrance and exit wounds is adequate for low velocity gunshot injuries to the forearm with minor visible soft tissue injury, and that bridge plating with minimal surgical dissection through the zone of injury is sufficient to achieve reliable Several studies have also examined the effectiveness of nonsurgical treatment in non-displaced or minimally displaced forearm fractures resulting from low-velocity firearms. Elstrom, et al. reported on fourteen patients that were treated with casting [12]. In eight non-displaced single bone fractures, seven had good outcomes. In six displaced fractures, closed reduction and casting lead to poor outcomes in four patients. Lenihan ,et al. reported on thirty-seven patients with civilian gunshot wounds to the radius and ulna [13]. Twenty-three patients with non-displaced fractures were treated by closed means with twenty-one showing good outcomes. However, in the fourteen patients with displaced fractures, the outcomes of the eight patients who had closed reduction were worse than the six patients treated surgically.
Dickson, et al. prospectively evaluated patients with non-displaced fractures treated as outpatients with closed reduction and casting [3]. Only one patient in their study went on to delayed union [3]. also reported excellent results in patients of non-displaced in patients treated with cephalothin [7]. The study also showed no statistically significant difference in infection rate between the control group (13.9%) and a group treated with penicillin and streptomycin (9.7%) [7]. Conversely investigated the efficacy of antibiotics in a similar patient population and showed no significant difference in infection rate between the control group and the experimental group treated with at least twenty-four hours of intravenous cefazolin [2]. concluded in a prospective study that short-term intravenous antibiotics did not decrease the risk of infection [9]. recommended the use of prophylactic antibiotics in high-velocity and intra-articular injuries but did not support the use of prophylactic antibiotics for low-velocity injuries [10].
Howland and Ritchey in a retrospective analysis concluded that prophylactic antibiotics were unnecessary in the treatment of lowvelocity gunshot fractures [11][12][13][14][15][16][17][18][19][20]. In our study, all patients were treated with intravenous first generation cephalosporin antibiotics, and in some cases additional antibiotics to treat other concurrent injuries. As no patient in our review developed osteomyelitis even with a large subset undergoing limited debridement, we support the use of a first-generation cephalosporin for 48 hours in patients reporting with open forearm fractures secondary to low-velocity gunshot wounds.
We recognize the following limitations of our study. First, it is retrospective in nature and carries all the associated risks of bias. It is additionally possibly biased towards more severe injuries since all included patients were admitted for at least 48 hours. Patients with minor gunshot forearm injuries and treated as outpatients had variable antibiotic regimens or no antibiotics and were not captured in this database. Thirdly, the patient population of this study is small, although it is larger than previously published studies. Furthermore, we had difficulty in contacting patients in our study for longer term follow up.

Conclusion
Forearm fractures caused by low velocity gunshot wounds in a civilian setting are often comminuted single bone injuries with minor soft tissue injury. Both the aggressive and limited debridement regimens resulted in reliable osseous union and no instances of osteomyelitis. These results suggest that immediate locked bridge plating with minimal debridement is a suitable option for the treatment of forearm fractures following low velocity gunshot injuries.