Treating Gunshot Wounds In The Lower Extremity
Pertinent Pearls For Surgical Debridement And Wound Stabilization
The wound may be classified as either a high or low velocity missile wound.18 When it comes to gunshot wounds involving fractures, treat them as open fractures.19 The Gustilo and Anderson classifications are useful when managing these wounds.3,20 We can usually consider low-velocity wounds less than eight hours old as type I open injuries, allowing for immediate wound closure following fracture stabilization.21 Low-velocity wounds older than eight hours are type II injuries. For high- and low-velocity wounds classified as Gustilo type II and III wounds, one can allow delayed closure.3 Wound closure typically occurs three to 10 days following debridement if there are no clinical signs of infection.22
In low-velocity missile wounds, minimal excision of the devitalized skin margins with irrigation of the resulting defect is sufficient.18 This is due to the lack of or minimal formation of temporary cavity involved in low-velocity missile wounds.23 High-velocity missile wounds require more extensive debridement. Excise the permanent wound tract as well as the muscle at a variable distance. Determine this by evaluating the consistency, color, contractility and capillary bleeding of the surrounding muscle. Remove all necrotic tissue and devitalized muscle.18
In both low- and high-velocity missile wounds of the lower extremity, fractures are common. At the time of debridement, one may utilize either internal or external fixation to stabilize unstable or displaced type I fractures caused by a low velocity missile.3 In type II or III fractures common with high-velocity missile wounds, incorporate external fixation away from the wound site until the wound is sterile. If there is a defect present between two main fracture fragments, the use of antibiotic beads or a polymethyl methacrylate spacer impregnated with antibiotics may maintain length.18
After the wound is free of infection and contamination, the surgeon may utilize internal fixation and bone grafting can take place if necessary. Stabilization and fixation of the fractures can be challenging because of variability and extensive damage. All types of fixation including Kirschner wires, Steinman rods, bone screws and plates, and external fixators may be necessary. It is not unusual for a patient to undergo multiple surgeries if the soft tissue and bone damage are extensive. In regard to high-velocity missile wounds, arthrodesis or amputation may also be necessary.24
An intra-articular injury is not always obvious. When there is doubt about joint penetration, the wound and joint require exploration, debridement with copious lavage and removal of any foreign debris. Intra-articular fractures, air within the joint and intra-articular hematomas are all indications that a joint has been infiltrated. If missile fragments remain within the joint, it can cause mechanical trauma with subsequent arthritis and loss of function. Also, any lead from the missile within the joint is absorbed and may cause lead toxicity.24-27
Although there is a possibility of lead toxicity from retained missile fragments anywhere within the body, it is unusual for lead absorption to occur in an extra-articular manner. When it comes to non-articular missile fragments, they do not require surgical removal and most often provide insignificant long-term complications.27 In addition, in cases of shotgun injuries, it may be impossible to remove all of the buckshot.