Abstract
Diabetic foot infections can have insidious presentations that can progress rapidly and lead to significant morbidity if not recognized and managed promptly. 55-year-old male with a history of type 1 diabetes mellitus, hypertension, and hyperlipidemia who underwent elective partial amputation of the right third digit for stable dry gangrene. On postoperative day nine, the patient presented severe pain, swelling, erythema, and systemic symptoms. Initial imaging showed soft tissue swelling; however, the patient’s clinical condition worsened, and computed tomography later revealed subcutaneous emphysema with concern for necrotizing soft tissue infection. Emergent bedside incision and drainage was performed followed by operative debridement, with cultures revealing a polymicrobial infection. Vascular evaluation demonstrated significant distal arterial disease limiting revascularization options. Despite aggressive surgical management, broad-spectrum antibiotics, and multidisciplinary care, progressive ischemia and infection resulted in necrosis, ultimately necessitating a transmetatarsal amputation. This case highlights the aggressive nature of diabetic foot infections and emphasizes the importance of early recognition, prompt surgical intervention, and coordinated multidisciplinary management to optimize limb salvage and patient outcomes.
Case description
55-year-old male with a past medical history of Type 1 Diabetes mellitus, hypertension, hyperlipidemia and previous surgical history of amputation on left foot first ray and right hand index finger was being followed in clinic for wound care of the left foot amputation site. Patient simultaneously had dry stable gangrene of the distal aspect of the right foot third digit, which the patient opted for removal for no reason other than cosmetic appearance. Patient underwent right foot third digit partial amputation with removal of distal and middle phalanx with resection of the head of the proximal phalanx, soft tissue and tendon. The surgical site was primarily closed on the day of surgery.
Post operative day (POD) 9, the patient started experiencing slight swelling to the right foot with tolerable pain, and a low grade fever. On POD 10, the patient had a red, hot, swollen foot ( Fig. 1 ) with significant pain which prompted the patient to report to the emergency department (ED). Patient had pain in the posterior calf, positive calf squeeze test, as well as constitutional symptoms of fever, nausea, and vomiting. Upon presentation to the ED, x-ray 3 view yielded diffuse soft tissue swelling without presence of soft tissue emphysema or any other pathological findings. The patient’s white blood count (WBC) was 29.5, erythrocyte sedimentation rate (ESR) was 16, and C- reactive protein (CRP) was 23.3, all correlating with the clinical picture. On physical exam, the foot was red, hot and swollen, dorsalis pedis (DP) and posterior tibialis (PT) pulses non-palpable but biphasic on Doppler, and diffuse pain on palpation, especially at the base of the hallux. The patient noted more pain at the base of the hallux than at the site of the amputation. The sutures from the surgical site of the amputated third digit were removed and minimal purulence was expressed. The amputation site was irrigated with betadine saline, packed with sterile iodoform packing, and dressed with betadine and dry sterile dressing. Wound cultures, gram stain and anaerobic cultures were obtained, and additional laboratory, vascular and radiographic studies were ordered. The patient was admitted and placed on empiric antibiotics of vancomycin and cefepime, and consults were placed with infectious disease, and vascular surgery. At this point the differentials included cellulitis, deep vein thrombosis, compartment syndrome, and complex regional pain syndrome.
Red, hot, swollen foot upon presentation to the ED.
Day 2 of hospital admission Arterial duplex of the right lower extremity revealed stenosis of the right distal superficial femoral artery with concomitant low velocity of the right peroneal artery. Venous duplex taken resulted in no deep vein thrombosis visualized. Patient’s WBC day 2 was 26.5, ESR 64, and CRP 21.8. Patient endorsed further increase in pain, clinically there were no improvements to the foot, and there was a focal area measuring.3cm x.2 cm of a discoloration at the dorsal base of the hallux ( Fig. 2 ). The patient was informed he may have an abscess which may necessitate incision and drainage. Patient was not amenable to bedside incision and drainage at the time due to pain, and wanted further testing and another clinical opinion prior to any invasive intervention.
Focal area of necrosis at the base of the hallux.
On Day 3, the patient’s labs were up trending again with WBC of 27.5 and presence of a left shift in neutrophils. Clinically, the focal area of discoloration had blistered and increased to the entirety of the base of the hallux with extension laterally and plantar into the first interspace ( Fig. 3 ). There was also an absence of all resting skin tension lines. The patient was amenable for a bedside incision and drainage. A STAT CT was also ordered for the patient.
Formation of blistering and necrosis at the lateral hallux base.
Intervention/approach
The patient was consented for emergent bedside incision and drainage for right foot. Patient was aseptically prepped and blocked using 20cc of 2% lidocaine; once anesthetized a sterile 15 blade was pressed into the dorsal aspect of the foot between the first and second metatarsal head and incision was carried town towards the interspace. A hemostat was used to examine all quadrants of the abscess. Approximately 7cc of dishwater pus was expressed on exsanguination. Hemostat was used to spread tissue and an additional 3cc of dishwater pus and bubbles were expressed. Of note there was no communication found between the first interspace to the original amputation site of the third digit.
The CT scan of the right food yielded the following findings; Prominent subcutaneous emphysematous changes of the right forefoot tissues surrounding the distal metatarsal bones extending to the level of the midfoot dorsally ( Fig. 4 ). Correlate with clinical parameters for possible necrotizing fasciitis. The patient was booked for further debridement and washout right foot in the operating room on the evening of day 3. Intraoperatively the incision site was extended proximally both dorsally and plantarly, sharp and blunt dissection was carried out to remove all nonviable tissue as well as explore any proximal tracking abscess. Repetitive debridement and irrigation with pulse lavage was conducted, and proximal tracking was present from the plantar head of the first metatarsal, extending proximal medially towards the base of the first metatarsal and midtarsal bones. Attention was directed to the third digit amputation site, the proximal phalanx was resected, and the wound was pulse lavaged. There was no communication found proximally between the first interspace and third digit besides from the one created during the earlier bedside I&D. Repeat wound culture, gram stain, and anaerobic cultures were obtained as well as bone cultures. All surgical wounds were pulse lavaged multiple times, followed by application of retention sutures using prolene, and dressed with half strength Dakin’s soaked gauze.
CT scan indicating soft tissue emphysema of the right forefoot.
Day 4 during dressing change, the patient’s hallux and second digit appeared purple, dusky, and cyanotic, prompting a stat vascular consult to assess viability ( fig. 5 ). Bedside doppler was biphasic for the DP, PT and anterior tibial artery. Since further OR debridement was indicated with podiatry due to presence of purulence and malodor, vascular surgery suggested a joint operative would be beneficial in which an angiogram could be conducted with possible angioplasty if warranted to help facilitate wound healing. Patient was booked for angiogram and further debridement and washout of right foot due to necrotizing fasciitis.
