10.15 Puncture wounds

agk’s Library of Common Simple Emergencies

Presentation

Most commonly, the patient will have stepped or jumped onto a nail. There may be pain and swelling but often the patient is only asking for a tetanus shot and can be found in the emergency department with his foot soaking in a basin of iodine solution. The wound entrance usually appears as a linear or stellate tear in the cornified epithelium on the plantar surface of the foot.

What to do:

• Obtain a detailed history to ascertain the force involved in creating the puncture and the relative cleanliness of the penetrating object. Note the type of footwear (e.g., tennis or rubber-soled shoe) and the potential for a retained foreign body. Ask about tetanus immunizations and underlying health problems that might diminish host defenses.
• Clean the surrounding skin and carefully inspect the wound with the patient lying prone, with good light and adequate time. Examine the foot for signs of deep injury such as swelling and pain with motion of the toes. Although unlikely, test for loss of sensory or motor function.
• If the puncture was created by a slender object like a needle or tack and the patient is positive that it was removed intact, no further treatment may be necessary. If there is any question as to whether the object may have broken off in the tissues, obtain x rays. Most metallic and glass foreign bodies are seen on plain radiographs, but plastic, aluminum and wood can be radiolucent and require ultrasound, CT or MRI.
• Most puncture wounds only require simple debridement and irrigation, but with deep, highly contaminated wounds, seek orthopedic consultation to consider a wide debridement in the operating room to prevent the catastrophic complication of osteomyelitis.
• Saucerize the puncture wound using a #10 scalpel blade to remove the cornified epithelium and any debris that has collected beneath its surface. Alternatively, the jagged epidermal skin edges overlying the puncture track may be painlessly trimmed.
• If debris is found, gently slide a large-gauge blunt needle or an over-needle catheter down the wound track and slowly irrigate with a physiologic saline solution until debris no longer flows from the wound. At times, a small amount of local anesthesia will be necessary to accomplish this.
• Provide tetanus prophylaxis.
• Cover the wound with a bandage, instruct the patient on the warning signs of infection, and arrange follow up in two days. Spend some time educating the patient and documenting the injury. Address the chance of delayed osteomyelitis, the chance of irretrievablely deep foreign matter, the impossibility of preventing infection with prophylactic antibiotics and the importance of seeking medical attention for discomfort persisting two or three weeks post injury.
• Patients presenting after a day will often have an established wound infection. In addition to the debridement procedures described above, they should respond to oral antistaphlococcal antibiotics, non-weight-bearing rest, elevation, and frequent soaking. Culture any drainage and reassess in one to two days.

What not to do:

• Do not be falsely reassured by having the patient soak in Betadine. This does not provide any significant protection from infection and is not a substitute for debridement, saucerizion and irrigation.
• Do not attempt a jet lavage within a puncture wound. This will only lead to subcutaneous infiltration of your irrigant and potential spread of foreign material and bacteria.
• Do not get x rays for simple nail punctures except for the unusual case where large particulate debris is suspected to be deeply imbedded within the wound.
• Do not routinely prescribe prophylactic antibiotics. Reserve them for established infections.
• Do not begin soaks at home unless there are early signs of infection developing.

Discussion:

Small, clean, superficial puncture wounds uniformly do well. The pathophysiology and management of a wound is dependent upon the material that punctured the foot, the location, depth, time to presentation, footwear and underlying health status of the victim. Punctures in the metatarsal-phalangeal joint area may be of higher risk of bone and joint involvement. Children brought by a parent, adults with on-the-job injury and patients seeking tetanus shots tend to present earlier and thus have a lower incidence of infection. Patients who present after 24 hours may have an early subclinical infection. Unsuspected fragments of sock or rubber sole are a major source of potential infection.

When the foot is punctured, the cornified epithelium acts as a spatula, cleaning off any loose material from the penetrating object as it slides by. This debris often collects just beneath this cornified layer which then acts like a trap door holding it in. Left in place, this debris may lead to lymphangitis, cellulitis or abscess. Saucerization or excision of wound edges allows for the removal of debris and the unroofing of superficial small foreign bodies or abscesses found beneath the thickly cornified skin surfaces.

Osteomyelitis caused by Pseudomonas aeruginosa remains the most devastating sequela. The incidence of osteomyelitis is estimated to be between 0.4% and 0.6%. Nails through tennis shoes into the metatarsal heads are high risk injuries and should be referred for orthopedic follow up.

References:

• Verdile VP, Freed HA, Gerard J: Puncture wounds to the foot. J Emerg Med 1987;7:193-199.
• Patzakis MJ, Wilkins J, Brien WM, Carter VS: Wound site as a predictor of complications following deep nail punctures to the foot. West J Med 1989;150:545-547.
• Fitzgerald RH, Cowan JDE: Puncture wounds of the foot. Ortho Clin N Am 1975;6(4):965-972
• Chisholm CD, Schlesser JF: Plantar puncture wounds: controversies and treatment recommendations. Ann Emerg Med 1989;18:1352-1357.
• Schwab RA, Powers RD: Conservative therapy of plantar puncture wounds. J Emerg Med 1995;13:291-295.

Illustration

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