Motor Vehicle vs Deer: An Antler Injury to the Ring Finger

To the Editor:

The literature is limited with regard to the treatment of patients after traumatic contact with deer. We present an interesting mechanism of motor vehicle collision vs deer with an isolated penetrating injury of the patient's hand from a deer antler. We also recommend an antibiotic regimen for treating penetrating deer antler injuries.

In the United States, an estimated 150 people die each year in more than 1.5 million traffic accidents involving collisions with deer. This imposes a significant financial burden of $1.1 billion annually on the insurance industry.^1,2 A collision with a deer may result in massive trauma to the human, with common injury sites involving the head, face, and neck. ³ About one half to two thirds of deer-related car crashes occur in the months of October, November, and December. This increased incidence of collisions is associated with heightened migration due to mating and hunting seasons and with a change in food supplies. ⁴ Deer commonly feed on green plants around lakes and swamps in the summer, but they head toward dry ground in fall and winter, which may involve crossing rural roads or highways. ³ Since these animals are most active at dawn and dusk, most collisions occur around the times of sunrise and sunset. ¹ Deer are usually more cautious and avoid entering an open space in the daylight compared to nighttime, possibly because of the strangeness of a highway environment. Dusk is a period of high activity for deer and a period of low visibility for drivers, which results in an abrupt increase in the crash rate during dusk hours. ¹

Depending on the species, a collision with a deer may result in the body of the animal partially penetrating the vehicle through the windshield and/or may result in a violent bending of the roof just above the heads of the front-seat passengers. Typically, the most serious and fatal injuries result from a massive blow to the head, with the risk of injury correlating with the deformation to the car. ³

In late November, an 18-year-old right hand–dominant, previously healthy female presented with an injury to her left ring finger. The patient had been a restrained driver involved in a motor vehicle collision with a deer at 6:00 pm. The patient reported no loss of consciousness and actually witnessed the antler of the deer hitting and penetrating through the windshield; ultimately a portion of the antler landed on the rear seat. The piece of the antler brought in by the patient is shown in Figure 1. The tine of the antler lacerated her left ring finger and fractured it at the proximal phalanx in a transverse fashion. This was her sole injury and is depicted in Figure 2. On presentation to the emergency department, there was some soft tissue swelling with an obvious clinical fracture of the left fourth proximal phalanx. The fracture was unstable. Capillary refill in the fourth digit was excellent, with normal sensation. There was minimal flexor and extensor function on examination. The extensor tendon appeared to be injured longitudinally and was not transected. The plain radiograph of the left hand revealed a displaced transverse fracture of the fourth finger with overlying soft tissue injury. There were no foreign bodies or other bony injuries.

Figure 1

A piece of deer antler that fractured the patient's ring finger

Figure 2

Dorsal view of the left hand with an axial fracture traversing the entire proximal phalanx of the ring finger

The patient received 1 dose of a gram of cephazolin intravenously and was taken to the operating room for irrigation, exploration, and open-reduction internal fixation of the left fourth digit proximal phalanx by the plastic surgery hand service. Upon achievement of adequate general anesthesia, the wound was explored; it was noted that the extensor mechanism was cut sagittally and the web space had a complex laceration. The wound was irrigated with a Pulsavac (Zimmer Inc, Swindon, UK), and with fluoroscopic guidance, 2 cross-oblique 0.035 K wires were placed across the fracture site. The extensor mechanism was repaired with 5-0 Ethibond sutures, and the skin was closed using 4-0 interrupted nylon sutures. The total length of the closure was 8 cm. The hand was placed in a splint for protection. The patient was later discharged home with no further antibiotics. At follow-up the patient was started on active range of motion of the left hand with occupational therapy. Six weeks later, the pins were removed. The patient recovered well, with full function of her left hand and complete recovery of her fourth finger.

The trajectory force from the tine of the deer antler affected the patient's left ring finger and resulted in an open proximal phalanx fracture. Any accident caused by contact with a deer carries a heightened possibility for transmission of infectious disease. The most common infectious diseases associated with deer collisions include Arcanobacterium pyogenes, Haemonchus controtus, Salmonella, Mycobacterium avium, and Paratuberculosis. ⁵

About 13% of road-killed deer exhibit debilitating conditions predisposing them to motor vehicle collisions. ⁵ The typical problems revealed during necropsy include chronic purulent infections involving the cranial region, usually intracranial abscesses and/or purulent meningoencephalitis. At necropsy many deer have evidence of missing antlers, open wounds, or scars around the antlers or atypical antlers secondary to structural fragility. Other bacteria cultured from wounds in close proximity to the deer antlers have included Bacteroides, Citrobacter, Corynebacterium, Enterobacter, Pasteurella multocida, Serratia marcesens, Staphylococcus aureus, and Staphylococcus sciuri. ⁵ Given this vast range of bacteria, a broad antibiotic coverage, to include gram negatives and anaerobes, would be an appropriate regimen in patients injured by deer. The literature is limited with regard to the surgical treatment of patients after traumatic contact with deer, and the optimal duration of antibiotic therapy for grossly contaminated wounds is still controversial. Generally a 3-day course is recommended, though 24 hours of antibiotics may be sufficient. ⁶ However, if the injury or wound site becomes infected, a 14-day course of treatment should be considered for soft tissue wounds and a 21-day course for infections involving joints or bones. ⁷ For prophylaxis, all such patients should receive tetanus prophylaxis as indicated, aggressive irrigation of wounds, and an antibiotic regimen with good gram-negative and anaerobic coverage. The antibiotics should include a third- or fourth-generation cephalosporin, such as ceftriaxone or cefepime, respectively, for broad gram-positive and gram-negative coverage and a tetracycline, such as doxycycline or minocycline, for anaerobic and atypical coverage. An alternative for penicillin- or cephalosporin-allergic patients would be a fluoroquinolone such as ciprofloxacin or levofloxacin.

In summary, for a patient presenting to the emergency department within 3 hours of an open fracture from a penetrating deer antler injury, we recommend a one-time prophylactic dose of intravenous ceftriaxone (2 g) and oral doxycycline (100–200 mg).