Full Article

Barry Rosenblum, DPM, Drew Taft, DPM, and Kevin Riemer, DPM

Given the challenges of treating puncture wounds, these authors emphasize a thorough diagnostic work-up, review pertinent guidelines and explore current concepts on the use of prophylactic antibiotics.

Regardless of your type of practice or institution, it is inevitable that you will come across puncture wounds. In fact, puncture wounds are probably more common than we think as many people delay or never seek medical attention.

Most puncture wounds will heal uneventfully but approximately 10 percent of those people who delay medical evaluation will develop a complication.1 Problems do not always arise from the initial insult but often from inadequate history, under-treatment and inadequate follow-up. When it comes to puncture wounds, there can be considerable sequelae of complications including cellulitis, osteomyelitis, foreign body granulomas and septic joints.

Puncture wounds are common in children. About 1 percent of all emergency department visits by children are due to puncture wounds.² Puncture wounds are also common in people who work outdoors, at construction sites and obviously in those people who tend to walk barefoot in or out of the house.²

Regardless of who presents to your office, it is important to know how to evaluate and treat these patients and what you may do differently, if anything. It is also important to know if patients have comorbidities, including diabetes or some other condition that may impede their ability to heal.

The initial presentation will vary widely, depending on the puncture object and the wound it created. Some patients may know they stepped on an object but do not have any pain.They may be curious to see if there is anything embedded and if they should do anything. Others will have trouble walking and may have an injury with signs including redness, swelling and pain.

In either case, it is important to obtain a detailed history of the sequence of events and note what the object may have been, when it happened, and the environment in which it happened. Also note the shoe gear the patient was wearing.This information is vital in helping to decide how aggressive one should be with treatment as it will guide any relevant considerations with wound care, antibiotics, tetanus prophylaxis and/or surgical intervention.

Pertinent Diagnostic Pointers

The clinical evaluation should include a detailed, problem-focused exam but should not exclude looking at the rest of the foot. Neurovascular and musculoskeletal exams are crucial.

Pinpointing the location of the wound and determining the presence of a foreign body are important. Management will be very different when dealing with small foreign bodies like easily visualized superficial splinters as opposed to a small entrance wound without a visible foreign body. In the latter scenario, the depth and location of the embedded material are unknown. This is especially the case after instances of flying shards of material or shattered glass.

Determining the depth is essential. If one needs to remove the foreign body, the depth of the wound will dictate whether one can do it in the office under local anesthesia or whether controlled hemostasis and monitored anesthesia are necessary. Some may also argue it is important to determine whether a potentially contaminated foreign body is embedded within minimally vascularized tissue like fascia, tendons and fat because it will increase the risk of infection.

There are a number of diagnostic tools for the detection of foreign bodies. Tools include radiographs, xerograms, ultrasound, CT or MRI.With or without knowing the nature of the foreign body, it is standard practice to obtain plain radiographs in at least two views (AP and lateral). An X-ray is a quick, sensitive and specific test for any metallic object, and can also identify glass foreign bodies, depending on the size. One can also identify a concomitant osseous abnormality that may have resulted from the puncture wound. For non-radioopaque or smaller objects, other tests are useful.

Before subjecting patients to expensive and/or other radiating modalities, one should consider ultrasonography. Ultrasound is patient friendly, quick and can accurately display the size, shape, orientation and composition of the object. Podiatrists may also consider removing a foreign body under ultrasound guidance.

Computed tomography scans and MRI become very useful when you need a more detailed study.The crosssectional views will leave no doubt in locating the object.They also assist in evaluating for bony abnormalities or distinguishing between tissue planes and soft tissue structures.

Addressing Key Questions To Facilitate Appropriate Treatment

Some of the key factors in treating a puncture wound and/or removing a foreign body are pain and clinical signs of infection. Unfortunately, there is a large subset of podiatry patients who may not accurately demonstrate these symptoms. Patients with diabetes are cursed with several disease processes that can inhibit them from feeling a noxious stimuli associated with a puncture wound and mounting an appropriate defensive response. In many cases, an infection is present by the time a patient sees a physician. There can also be significant morbidity and associated mortality as well.

Armstrong, et al., compared the morbidity of puncture wounds in diabetic versus non-diabetic adults.They found the risk of amputation was 46 times greater and the risk of multiple operations was five times greater in patients with diabetes than in nondiabetics. Also, the interval from injury until surgery was nearly twice as long for those with diabetes.³

Once you have combined the historical and clinical picture, one needs to determine how to treat the patient and the wound. While the literature provides algorithms and scoring systems like the University of Texas Puncture Wound Scoring System, one’s treatment approach should ultimately be governed by what is best for the patient.¹

Is there a retained foreign body? If not, one may only need to provide treatment for periwound cellulitis or a wound infection. Accordingly, one would consider the use of parenteral versus oral antibiotics, and facilitate appropriate wound care.

For more deep, contaminated or infected wounds, the patient may require a formal incision and drainage in the operating room. If the patient still has a retained foreign body or bodies, physicians need to address several important questions. For example, how sensate is the patient? Will local infiltration be enough to anesthetize the patient or will monitored or even general anesthesia be required? Also, is the foreign body accessible so one can limit soft tissue dissection? Otherwise, utilizing hemostasis with a tourniquet is necessary in order to visualize the field adequately.

	Here one can see a sewing needle embedded in the first interspace.
	One can use fluoroscopy and triangulation or a grid system to locate deeply embedded foreign bodies such as this sewing needle. These methods can prevent additional tissue damage and reduce operating room time.

When Should You Utilize Surgical Intervention?

The goal of treating puncture wounds is to convert a contaminated wound into a clean wound. Irrigating the wound with saline solution helps decrease the bacterial count, prevents colonization and flushes any debris from the wound.This is acceptable in superficial wounds, which are small and ideally discovered in less than six hours. One should also determine the tetanus status of all patients and update it as needed (see “What About Tetanus Immunization After Injury?” on page 113).⁴

In regard to puncture wounds that have entered deep tissue, podiatrists will need to treat these wounds in a more aggressive manner. Penetration into the deep structures, including tendons and joint capsules, may allow infectious organisms to become problematic due to the relative avascularity of these structures. Krych and Lavery have described an objective classification system to help determine the appropriate treatment course (see “A Guide To The University Of Texas Puncture Wound Scoring System” on page 113).⁵

Incision and drainage is required in wounds that are deep, contaminated or infected. Researchers have described the bacterial inoculum of 106 as inducing an infection.However, foreign bodies reduce the amount of inoculum by a power of 104.

One should open and drain any abscess. It is important to remove all devitalized tissue as well as foreign material. Send this tissue for culture and sensitivity. If bone has been penetrated, proceed with surgical debridement and obtain a pathologic evaluation. If the bone has not been penetrated but is exposed, consider the bone inoculated and provide appropriate treatment.

Then flush the wound with copious amounts of irrigation. Low-pressure irrigation seems to be more beneficial than high-pressure irrigation. Higher pressure can lead to displacement of foreign matter secondary to hydrodissection along tissue and fascial lines. This theoretically can cause dissemination of bacteria deeper into the surrounding tissue. One may then leave the wound packed open or closed over a drain to prevent hematoma formation, especially in large spaces.After the infection has cleared, one may fully close the wound.

One can use fluoroscopy and triangulation or a grid system to locate deeply embedded foreign bodies. These methods can prevent additional tissue damage and reduce operating room time.

A college student presented with hardwood flooring impaled in the fourth interspace (as shown above). The patient had been walking barefoot.

What You Should Know About The Microbiology Of Puncture Wounds

Understanding the likely types of bacteria one may encounter in a puncture wound is important to ensure proper antibiotic selection. Physicians also need to consider the environment where the puncture wound occurred. For example, it is important to know if the puncture wound occurred in a barnyard or pond.

The most common gram-positive organisms isolated from puncture wounds are (but not limited to): Staphylococcus aureus, Staphylococcus epidermidis and Streptococcus species. Also keep in mind that researchers have isolated gram-negative organisms such as Escherichia coli, Proteus and Klebsiella species.⁶

Other authors have isolated Eikenella corrodens from human bite wounds and isolated Pasteurella multocida from dog and cat bites.⁷ Other organisms such as Aeromonas hydrophila, Vibrio vulnificus and Mycobacterium marinum have been isolated from puncture wounds that have occurred in brackish water.

Pseudomonas is the most common organism responsible for osteomyelitis following a puncture wound. Researchers have shown an association between individuals wearing rubbersoled shoes and pseudomonal osteomyelitis.² When a nail or other object penetrates the shoe and then the foot, it inoculates the wound with the pseudomonal organism found on the shoe, and sometimes material from the shoe. The wound may be benign and initially heal, but there may be a subsequent problem weeks to months later.

Prophylactic Antibiotics: What The Research Reveals

The use of prophylactic antibiotics remains a controversial issue when it comes to puncture wounds. Currently, there are no prospective, randomized trials that have examined the role of antibiotic administration in the prevention of infection following puncture wounds.This lack of data makes it difficult to offer recommendations on antibiotic therapy and duration. The decision to administer antibiotics is up to the discretion of the treating physician.

Two clinical trials have established that a seven- to 14-day course of therapy is sufficient for treatment of plantar wound infections when one combines this with initial surgical intervention.^8,9

In one study, researchers administered ciprofloxacin (400 mg IV twice daily for the first 24 hours followed by 750 mg PO twice daily) to 23 adults suffering infections of the plantar surface of the foot after nail puncture wounds. The duration of therapy was either seven days for cellulitis or 14 days for early bone involvement (defined as osteochondritis based on radiography or bone scan).

The researchers found that ciprofloxacin was universally successful when they combined it with initial surgical drainage, debridement or exploration. Microbiologic analysis revealed that 18 patients had P. aeruginosa, two had S. aureus and one had both bacteria.All isolates were susceptible to ciprofloxacin.⁹

The other study was a 10-year evaluation of 77 children with puncture wound infections caused by Pseudomonas species. Short-course antibiotic treatment was successful in those children who underwent early surgical intervention. The average duration of treatment was 7.5 days following surgery. Patients received therapy intravenously for the duration of treatment for bone or joint involvement. Only two patients relapsed and both had previously undetected septic arthritis.⁸

First-generation cephalosporins such as cephalexin or cefadroxil are sufficient for most superficial puncture wounds.With the increasing incidence of community-acquired methicillin resistant Staphylococcus aureus (CAMRSA), the use of trimethoprim/sulfamethoxazole may also be appropriate. Broad-spectrum antibiotics are recommended for use in patients with diabetes. One may use amoxicillin/clavulanic acid, trimethoprim/sulfamethoxazole or combinations like clindamycin and ciprofloxacin.

Those who suspect Pseudomonas may use the following antibiotics. The third-generation cephalosporin ceftazidime and fourth-generation cefepime are good initial choices if the patient is hospitalized. One may also use fourth-generation penicillins like piperacillin/ tazobactam or carbapenems like meropenem or imipenem/cilastin.

Physicians may also consider aminoglycosides like gentamycin and tobramycin.Tobramycin is reportedly two to four times more active against pseudomonal organisms in comparison to gentamycin but has more interactions and a greater risk of side effects.

Ciprofloxacin, therefore, is usually the drug of choice for puncture wound infections secondary to Pseudomonas because patients can take it orally. Using other newer fluoroquinolones such as levofloxacin, gatifloxacin and moxifloxacin is not advised because there is less activity than ciprofloxacin against Pseudomonas aeruginosa, contributing to the increasing resistance (currently near 32 percent).¹⁰

Although physicians utilize ciprofloxacin extensively in adults, the agent is not approved for routine childhood administration because of concern about cartilage toxicity. Consequently, pediatric usage of fluoroquinolones is reserved, except for the treatment of selected illnesses. At this point, one should defer to infectious disease specialists to determine appropriate usage.

This ultrasound shows a foreign body in the plantar aspect of the forefoot. Ultrasound is patient friendly, quick and can accurately display the size, shape, orientation and composition of the object.

In Summary

Puncture wounds of the foot are common and can pose a challenge for the physician to provide proper treatment. If these wounds are not treated properly, serious complications such as deep abscess formation, granuloma formation, tissue necrosis and osteomyelitis can occur. By treating these wounds aggressively and in a timely manner, podiatrists can limit the risk of complications for these patients.

What About Tetanus Immunization After Injury?

Td= adult tetanus and diphtheria toxoids; TIG=tetanus immune globulin When tetanus toxoid is indicated, administration of Td is preferable. The typical dose of tetanus immune globulin is 250 mg, administered intramuscularly at a separate site from tetanus toxoid.4

A Guide To The University Of Texas Puncture Wound Scoring System

Age of Wound

• Less than six hours (1 point)
• More than six hours but less than twenty four hours (2 points )
• More than 24 hrs (3 points)

Classification

• Small wound with sharp clean edges, superficial (1 point)
• Ragged, irregular margins of moderate depth (2 points)
• Irregular wound edges with necrotic tissue or foreign body (3 points)

Depth

• Involving only the epidermis (1 point)
• Through the dermis with no structural involvement (2 points)
• Through the dermis with structural involvement (3 points)
• Presence of concomitant disease (1 point)

Footwear Worn

• None (1 point)
• Stockings or shoes, but not both (2 points)
• Stockings and shoes (3 points)

Radiographic Exam

• No evidence of osseous involvement (0 points)
• Evidence of osseous involvement (9 points)
  

Wound Score Interpretation

Score: Treatment

• 1-4: Local cleansing and observation
• 5-8: Local cleansing, incision and drainage, exploration for foreign body and drain placement
• >9: Mandatory incision and drainage, wound lavage, hospitalization and intravenous antibiotics

Dr. Rosenblum is the Director of Podiatric Residency Training at the Beth Israel Deaconess Medical Center in Boston, He is an Assistant Clinical Professor of Surgery at Harvard Medical School.
Dr. Taft is a third-year resident in podiatric surgery at Beth Israel Deaconess Medical Center in Boston.
Dr. Riemer is a third-year resident in podiatric surgery at Beth Israel Deaconess Medical Center in Boston.

References
1. Haverstock BD, Grossman JP. Puncture wounds of the foot. Clin Podiatr Med Surg. 16: 583- 596, 1999.

2. Fisher MC, Goldsmith JF, Gilligan PH. Sneakers as a source of Pseudomonas aeruginosa in children with osteomyelitis following puncture wounds. J Pediatr 106:607-609, 1985.

3. Armstrong DG, Lavery AL, et al. Surgical morbidity and the risk of amputation due to infected puncture wounds in diabetic versus nondiabetic adults. South Med J. 90: 321-326, 1997.

4. Centers for Disease Control and Prevention. Diphtheria, tetanus and pertissus: recommendations for vaccine use and other preventive measures. Recommendations of the Immunization Practices Advisory Committee (AICP).MMWR 40:21, 1991.

5. Krych SM, Lavery LA. Puncture wounds and foreign body reactions. Clin Podiatr Med Surg 7:725-731, 1990.

6. Joseph WS, LeFrock JL. Infections complicating puncture wounds of the foot. J Foot Surg 26:530-532, 1987.

7. Joseph WS. Infections following trauma. In Handbook of Lower Extremity Infections, p. 69-74, Churchill Livingston,N.Y., 1990.

8. Jacobs RF, McCarthy RE, Elser JM. Pseudomonas osteochondritis complicating puncture wounds of the foot of children: a 10-year evaluation. J Infect Dis 1989; 160: 657.

9. Raz R, Miron,D. Oral ciprofloxacin for treatment of infection following nail puncture wounds of the foot. Clin Infect Dis 1995; 21:194.

10. Karlowsky JA, Jones ME, et al. Stable antimicrobial susceptibility rates for clinical isolates of Pseudomonas aeruginosa from the 2001-2003 Tracking Resistance in the United States Today Surveillance Studies. Clinical Infectious Diseases 40:S89–S98, 2005.

Additional Reference
11. Laughlin TJ,Armstrong DG, et al. Soft tissue and bone infections from puncture wounds in children.West J Med. 166: 126-128, 1997.

Editor’s note: For a related article, see “Inside Insights On Puncture Wounds” in the November 2006 issue of Podiatry Today.