Infected Diabetic Foot Ulcer

15 Jun 2022

Case Report

Hospital Middlemore Hospital, Auckland, New Zealand

Wound closure was achieved for a chronic ulcer with exposed tendons; NovoSorb® BTM was retained despite an infection occurring one week after application.

The diabetic patient presented with an infected ulcer on the dorsum of her foot. After debridement, a large defect was present with exposed extensor tendons. NovoSorb BTM was applied with adjunct Negative Pressure Wound Therapy (NPWT). After discharge to a care facility, problems were encountered with the NPWT and a subsequent infection was observed. NovoSorb BTM was retained while the infection was treated. Following full integration a skin graft was applied to achieve wound closure.

Figure 1: Wound prior to debridement.

Figure 2: 2 weeks post NovoSorb BTM application; signs of infection and cellulitis of the toes.

Figure 3: 3 weeks post NovoSorb BTM application; matrix retained despite infection.

Figure 4: 4 weeks post NovoSorb BTM application; infection resolved and uniform integration within the matrix.

Figure 5: 4.5 weeks post NovoSorb BTM application; delamination reveals a viable neodermis.

Figure 6: 4 months post grafting; good cosmetic outcome.

    Background

    A 73-year-old Caucasian female initially developed a small wound on the dorsum of her foot due to minor trauma. Due to her underlying diabetes and other comorbidities, including hypertension and anemia, the wound failed to heal and became secondarily infected, developing into an infected DFU.

    Treatment

    Initial treatment involved serial debridement in controlling the infection and removing all non-viable tissue (Fig. 1). Intravenous antibiotics were administered, and her diabetes management was reviewed to ensure tight glycaemic control. After the infection was controlled and all non-viable tissue was removed, the patient was left with a large defect with exposed extensor tendons on the dorsum of the foot.

    Due to the exposed tendons, immediate split-thickness skin grafting was not an option. With such a large wound, there were no local flap options. A free flap would have been required for coverage, but a lengthy procedure was not advised due to the patient’s comorbidities.

    Intraoperatively, the wound edges were excised, and the wound bed was refreshed using hydrosurgery. NovoSorb BTM was applied and quilted with staples. An antimicrobial silver dressing was used, and a topical NPWT of 50mmHg was applied. The patient remained an inpatient until the first dressing change at one week, before being discharged to her care facility.

    Problems with the continuation of the topical NPWT were encountered, resulting in the machine being turned off for an unknown period. The patient was re-admitted to the hospital with clinical evidence of recurrent infection in the foot with NovoSorb BTM still in place. Cellulitis involving the toes was evident and purulent exudate originating beneath the matrix (Fig. 2). The infection was treated with intravenous antibiotics and daily topical wound care involving chlorhexidine washes and antimicrobial silver dressings. Over several days, the cellulitis resolved and exudate ceased. NovoSorb BTM developed a dry, yellow appearance that progressed to pink/red over time (Fig. 3). The infection was successfully treated with retention of NovoSorb BTM (Fig. 4), and delamination was performed 4.5 weeks after the initial application, revealing a well-developed neodermis (Fig. 5). A meshed split-thickness skin graft was applied
    for definitive closure.

    Outcome

    The skin graft had a near 100% take. The patient’s wound went on to heal uneventfully. At four months, a good cosmetic outcome was observed (Fig. 6).

    A 73-year-old Caucasian female initially developed a small wound on the dorsum of her foot due to minor trauma. Due to her underlying diabetes and other comorbidities, including hypertension and anemia, the wound failed to heal and became secondarily infected, developing into an infected DFU.

    Initial treatment involved serial debridement in controlling the infection and removing all non-viable tissue (Fig. 1). Intravenous antibiotics were administered, and her diabetes management was reviewed to ensure tight glycaemic control. After the infection was controlled and all non-viable tissue was removed, the patient was left with a large defect with exposed extensor tendons on the dorsum of the foot.

    Due to the exposed tendons, immediate split-thickness skin grafting was not an option. With such a large wound, there were no local flap options. A free flap would have been required for coverage, but a lengthy procedure was not advised due to the patient’s comorbidities.

    Intraoperatively, the wound edges were excised, and the wound bed was refreshed using hydrosurgery. NovoSorb BTM was applied and quilted with staples. An antimicrobial silver dressing was used, and a topical NPWT of 50mmHg was applied. The patient remained an inpatient until the first dressing change at one week, before being discharged to her care facility.

    Problems with the continuation of the topical NPWT were encountered, resulting in the machine being turned off for an unknown period. The patient was re-admitted to the hospital with clinical evidence of recurrent infection in the foot with NovoSorb BTM still in place. Cellulitis involving the toes was evident and purulent exudate originating beneath the matrix (Fig. 2). The infection was treated with intravenous antibiotics and daily topical wound care involving chlorhexidine washes and antimicrobial silver dressings. Over several days, the cellulitis resolved and exudate ceased. NovoSorb BTM developed a dry, yellow appearance that progressed to pink/red over time (Fig. 3). The infection was successfully treated with retention of NovoSorb BTM (Fig. 4), and delamination was performed 4.5 weeks after the initial application, revealing a well-developed neodermis (Fig. 5). A meshed split-thickness skin graft was applied
    for definitive closure.

    The skin graft had a near 100% take. The patient’s wound went on to heal uneventfully. At four months, a good cosmetic outcome was observed (Fig. 6).