10.15 Puncture wounds
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agk's Library of Common Simple Emergencies

Presentation
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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 collect- 
    ed 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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img/cse1015.gif

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