Puncture Wounds in
the Diabetic Foot
"Puncture wounds to the feet are common, and fewer than 15 percent develop complications, usually cellulitis. Most of these problems will resolve with conservative management." (1) Yet in the immunocompromised diabetic patient the average puncture wound is usually catastrophic. (see Figure 1 ) Patients with peripheral neuropathy, poor vascular supply, and other associated medical problems with diabetes will limit the patient's ability to heal without incidence. Lower extremity puncture wounds are common, especially during the summer months when people tend to go barefoot. Puncture wounds can be a difficult problem for both the physician and the patient if left untreated and / or mistreated. Objects like nails, glass, sharp metal objects, toothpicks, toys, and sewing needles contain bacteria which make diabetic puncture wounds very opportunistic for infection.
It is my experience that diabetic patients with puncture wounds develop more extensive complications than non-diabetic patients with similar wounds. The diabetic patient usually has some form of peripheral neuropathy which often causes the initial puncture wound to go undetected. The insensate foot will often be painfree at the time of injury which will delay the patient from seeking medical treatment. The prolonged interval between injury and treatment will often cause increased infection rate. People with diabetes usually have fluctuating glucose levels and poor nutrition which delays wound healing and causes the inability to fight off infection. These factors along with other medical problems of diabetes makes the treatment plan more extensive, and with increased catastrophic events. Possible results from diabetic puncture wounds include cellulitis, osteomylitis, digital ray resections, transmetatarsal, symes, below the knee amputations, and even death.
Dr. Michael J. Patzakis, and associates classified puncture wounds of the foot into three zones: Zone 1 includes the area over the neck of the metatarsals and extends to the ends of the toes, Zone 2 stretches from the distal end of the calcaneous to the metatarsal neck area, and Zone 3 overlies the calcaneous. Of the 36 patients who needed hospital care in Patzakis study, 35 or 97 percent had deep puncture wounds in Zone 1, one had an injury in Zone 3, and none had injuries in Zone 2. (2) Therefore according to this study, Zone 1 is the most common area for castastrophy in diabetic puncture wounds. (see Figure 2 )
History and Physical Examination
With a thorough history and a competent physical examination the physician can classify the puncture wound, and form an effective treatment plan for the diabetic patient. Before examining the patient a thorough history is mandatory. (3) The history should include a diabetic history, shoe gear, puncture object, location, time period before treatment, and tetanus immunizations. Other questions that should be asked include previous treatment, nature of injury, and was there pain associated with the initial puncture wound. An excellent history will lead the physician to anticipate complications and form an effective treatment plan. A good physical examination is just as important as a thorough history. Vital signs especially temperature is important in the diabetic foot. Neurological assessment tells the physician which areas of the foot is neuropathic. Vascular supply is important to assess wound healing potential and to determine cyanotic or gangrenous areas secondary to puncture trauma. Musculoskeletal assessment indicates areas of involvement of soft tissue and bone. It also tells the physician of other deformities that are possible complication areas. Dermatological evaluation is extremely important in puncture wounds to assess areas of cellulitis, erythema, and contamination. The Dermatological examination can also identify the location of the puncture wound and to determine the prognosis of the injury. Laboratory tests, radiographs, and other modalities like MRI studies, Doppler, and TcO2 studies can help in forming an effective treatment plan for the punctured diabetic.
Case Report # 1 - A 48 year old diabetic female presented to the emergency room with a swollen left foot of 5 days duration. One week prior the patient stepped on a dog bone that punctured through her tennis shoe. Patient denied retaining any foreign body. Her left foot became red, swollen, and painful with a gradual onset that progressively got worse. The patient denied fever, chills, nausea, and no treatment had been previously rendered. Patient has had diabetes mellitus type II for 16 years with a 10 year oral history of Diabinese and insulin therapy for the last 6 years. Family history is remarkable for an older brother and younger sister who both died from diabetes. Her father died from a myocardial infarction. Patient was admitted for abscess and cellulitis of the left foot secondary to a puncture wound. Incision and drainage procedure was performed on her Left 5th toe area. Her vital signs were stable and a treatment regimen consisted of local wound care and intravenous antibiotics. Six days later, the left 4th and 5th digits became gangrenous with infection of necrotic tissue. A partial 4th and 5th ray amputation and debridement of all necrotic tissue was performed. Gram stain and cultures revealed Staphylococcus Aures Beta Lactamase Negative, Group B Streptococcus and Pseudomonas Aeruginosa Other treatment modalities included whirlpool, radiographs, non invasive doppler studies, arteriogram, Tc02 studies, and hyperberic oxygen. Debridement of necrotic tissue was performed under local anesthesia 5 days after previous amputation. The patient is stable with a good healing granulation tissue covering the wound and is waiting for a full thickness skin graft. Long term therapy may include possible transmetatarsal amputation, if the skin graft fails or if other complications arise.
Case Report # 2 - A 17 year old IDDM male comes in for a painful left foot x 1 month. Patient states that he stepped on a nail that went through his tennis shoe about 1 month ago. States that he has been on oral antibiotics ( Keflex ) from his family practitioner x 2 weeks. States that his foot is not getting any better, swollen, painful to walk. States that his tetanus history is up to date. PMH - IDDM x 14 years. PSH - Tonsilectomy. Medications - Insulin. Allergies - NKDA. On Exam the patient has a painful swollen Left forefoot especially over the Left 4th MPJ area. Slight erythema noted. A small healed entrance wound noted L th MPJ area. No signs of pus. X-rays show no signs of Osteomylitis. Assessment - IDDM. S/P Puncture Wound Left foot x 1 month. Patient needs to have an incision and drainage procedure with IV antibiotic therapy. Plan - Incision and Drainage procedure performed under MAC anesthesia. Pulse Vac flush with GU antibiotics. Patient had some retained foreign body ( rubber from tennis shoe ) in the wound. Patient had a mid line placed in left arm. Patient was put on 6 weeks of IV antibiotic therapy. Patient got better immediately after performing the incision and drainage procedure. The patient recovered with no signs of Osteomylitis and no partial amputation. The goal of the incision and drainage procedure is to: Eliminate Infection, Minimize Tissue Damage, Prevent Osteomylitis, Avoid Amputation, and Limb Salvage.
The goal in treating puncture wounds is to: Obtain a through and accurate history, insure current tetanus immunity, ascertain the depth and path of injury, locate and remove the foreign bodies, clean the wound of debris and bacteria, provide a path for drainage and insure appropriate antibiotic coverage. (4) Treatment for diabetic puncture wounds is more extensive than for non diabetic patients. The Surgical Incision and Drainage procedure is a necessity to open the puncture wound site to allow drainage and decrease the potential for infection. Treatment also hospitalization, local wound care, and intravenous antibiotics. Patients may need a more includes tetanus prophalaxis, x-rays to rule out bone involvement and location of foreign body, aggressive procedure when signs of Cellulitis and Osteomylitis are present. Diabetic patients that see a physician immediately and are treated appropriately for puncture wounds usually have a lot better outcome than patients who delay treatment. Any delay in treatment can lead to a possible complication like ulceration and / or amputation. No two puncture wounds are alike, so treatment should always be tailored for the patient individual needs, signs, and symptoms.
Diabetic patients can handle an incision and drainage procedure they can not tolerate infection and pus. Diabetic puncture wounds need to be treated quickly, aggressively, and appropriately or the patient can develop a severe infection, osteomylitis, tissue damage, ulceration and / or amputation. Do not wait on a diabetic puncture wound, hoping that it will get better with antibiotics. By performing the incision and drainage procedure, this will decrease the bacterial count, allow drainage of the infection, and will help the antibiotics to be more effective. The importance of performing an Incision and Drainage procedure early for diabetic infections can not be underestimated. The procedure will help stabilize the patient, decrease the patient's pain, temperature, white blood count, infection, and sed rate. The incision and drainage will also help reduce hyperglycemia, and decrease the pathogen microbe count thus allowing the IV antibiotic therapy to be more effective. Diabetics can tolerate surgery, they cannot tolerate an infection. Diabetic infections are serious and should be treated appropriately and aggressively. A diabetic infection that is not treated quickly and correctly can lead to an amputation. Diabetic patients can avoid amputations by going to a qualified physicians who treat diabetic infections. The key to the diabetic foot care program is prevention. (5) Physicians can help prevent some puncture wounds from occurring by patient education on proper shoe gear. People with diabetes should never go barefoot. They should check the inside of their shoes with their hands, and perform a daily inspection of their feet. Patients with diabetes can avoid puncture wounds by picking up construction nails, 2 x 4's with protruding nails, and gather up broken glass. They should also be careful around sewing areas, sharp objects, and beware of any potential hazards. Complications from puncture wounds can be avoided by daily examination of the diabetic foot. When complications arise, diabetics that have good glucose control and good nutrition will probably heal better than someone who has poor nutrition and uncontrolled diabetes.
The key to the management of Cellulitis and/or Osteomylitis is the early recognition and prompt aggressive treatment. Treatment involves both medical management to include wound care and appropriate anti microbial therapy, and surgical resection of necrotic bone with debridement of devitalized soft tissue. (6) Diabetic puncture wounds are usually more severe than non diabetic puncture wounds because of poor vascular supply, peripheral neuropathy, and a delayed time period before medical treatment. Diabetic puncture wounds are usually more catastrophic do to decreased healing ability and other complications associated with diabetes.
Acknowledgment. Marva Myler-Jensen, M.Ed., for her contributions to this manuscript; Chris Alviso for drawing Fig 1.
Dr. Brian Richman is a podiatric physician specializing in diabetic foot care, foot and ankle surgery, biomechanics, sports medicine, and general podiatry care. He practices at Davis Hospital and Medical Center in Layton, Utah. For more information contact Dr. Richman at 1660 West Antelope Drive # 110 Layton, Utah 84041 or visit his web site at www.DrBrianRichman.com
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