Infectious Spondylodiscitis, Epidural Phlegmon, and Psoas Abscess Complicating Diabetic Foot Infection: A Case Report

Distant metastatic foci of infection in adult patients with diabetic foot - not as rare as we think?: case series and review of the literature

BACKGROUND

Diabetic foot is one of the common complications of diabetes mellitus. We report clinical and microbiological characteristics and outcomes of cases with distant metastatic foci of infection arising from diabetic foot.

METHODS

Retrospective review of adult patients with diabetic foot infection or diabetic foot ulcer who demonstrated distant metastatic foci of infection between August 2017 and December 2019. We performed a literature search of similar cases published until June 2020.

RESULTS

Twelve patients with diabetic foot infection or diabetic foot ulcer with distant metastatic foci of infection were identified. The median age of patients was 67.5 years (range 60.5-73.5 years) and 11 males. The most common distant metastatic foci of infection included endocarditis (n = 7) followed by septic arthritis (n = 3) and spine infections (n = 2). Five patients had multiple site and organ involvement. Staphylococcus aureus was the only organism isolated from blood (n = 11), diabetic foot (n = 7), and metastatic foci (n = 8) sources. Three patients died and three had a relapse of distant metastatic foci of infection. Thirty-eight cases were identified in the literature with similar characteristics.

CONCLUSIONS

Prevalence of distant metastatic foci of infection in adult patients with diabetic foot and burden of illness, in terms of mortality, morbidity, and length of hospital stay, appears to be underreported in the literature. A large prospective study is needed to assess the true prevalence of complications, associated risk factors, outcomes and prognostic factors.

Invasive Systemic Infection After Hospital Treatment for Diabetic Foot Ulcer: Risk of Occurrence and Effect on Survival

BACKGROUND

Diabetic foot ulcers (DFUs) threaten limbs and prompt hospitalization. After hospitalization, remote-site invasive systemic infection related to DFU (DFU-ISI) may occur. The characteristics of DFU-ISIs and their effect on mortality risk have not been defined.

METHODS

We conducted a retrospective cohort study of 819 diabetic patients hospitalized for treatment of 1212 unique DFUs during a 9-year period. We defined the index ulcer as that present at the first (index) DFU admission to our hospital. We defined DFU-ISI as a nonfoot infection that occurred after the index hospitalization and was caused by a microorganism concomitantly or previously cultured from the index ulcer. We determined the frequency, risk factors, and mortality risk associated with DFU-ISIs.

RESULTS

After 1212 index DFU hospitalizations, 141 patients had 172 DFU-ISIs. Of the initial 141 DFU-ISIs, 64% were bacteremia, 13% deep abscesses, 10% pneumonia, 7% endocarditis, and 6% skeletal infections. Methicillin-resistant Staphylococcus aureus (MRSA) caused 57% of the ISIs. Patients with initial DFU cultures yielding MRSA and protracted open ulcers had a high 24-month cumulative probability of DFU-ISI (31%) and all-cause mortality rate (13%). Analysis with Cox regression modeling showed that complicated ulcer healing (hazard ratio, 3.812; 95% confidence interval, 2.434-5.971) and initial DFU culture yielding MRSA (2.030; 1.452-2.838) predicted DFU-ISIs and that DFU-ISIs were associated with increased mortality risk (1.987; 1.106-3.568).

CONCLUSIONS

DFU-ISIs are important late complications of DFUs. Prevention of DFU-ISIs should be studied prospectively. Meanwhile, clinicians should aggressively incorporate treatment to accelerate ulcer healing and address MRSA into the care of diabetic patients with foot ulcers.

Diabetic foot complicated by vertebral osteomyelitis and epidural abscess

Vertebral osteomyelitis (or spondylodiscitis) is steadily increasing in Western countries and often results from hematogenous seeding, direct inoculation during spinal surgery, or contiguous spread from an infection in the adjacent soft tissue. We present the case of a 67-year-old white patient with type 2 diabetes who went to Hospital for high fever, back pain, and worsening of known infected ulcers in the left foot. Despite intravenous antibiotic treatment and surgical debridement of the foot infection, high fever and lower back pain continued. Bone biopsy and two consecutive blood cultures were positive for Staphylococcus aureus. A spinal magnetic resonance imaging (MRI) was performed, revealing serious osteomyelitis in L4 and L5 complicated by an epidural abscess. Contiguous or other distant focuses of infection were not identified. In this case, diabetic foot could be considered as a primary distant focus for vertebral osteomyelitis. Clinicians should consider vertebral osteomyelitis as a 'possible' diagnosis in patients with type 2 diabetes complicated by foot infection that is associated with fever and lower back pain.

LEARNING POINTS

Vertebral osteomyelitis is increasing in Western countries, especially in patients with type 2 diabetes.The primary focus of infection is the genitourinary tract followed by skin, soft tissue, endocarditis, bursitis, septic arthritis, and intravascular access.Diabetic foot could be a rare primary focus of infection for vertebral osteomyelitis, and, however, vertebral osteomyelitis could be a serious, albeit rare, complication of diabetic foot.Clinicians should keep in mind the many potential complications of diabetic foot ulcerations and consider vertebral osteomyelitis as a "possible" diagnosis in patients with type 2 diabetes and foot ulcers associated with nonspecific symptoms such as lower back pain.Early diagnosis and correct management of vertebral osteomyelitis are crucial to improve clinical outcomes.

Timing and prognosis of surgery for spinal epidural abscess: A review

Background:

The nonsurgical versus surgical management of spinal epidural abscesses (SEAs) remains controversial. Even with the best preoperative screening for multiple risk factors, high nonoperative failure rates are attended by considerable morbidity (e.g., irreversible paralysis) and mortality. Therefore, the focus remains on early surgery.

Methods:

Most papers promote early recognition of the clinical triad (e.g., fever [50%], spinal pain [92–100%], and neurological deficits [47%]) for SEA. They also identify SEA-related risk factors for choosing nonsurgical versus surgical approaches; advanced age (>65 or 80), diabetes (15–30%), cancer, intravenous drug abuse (25%), smoking (23%), elevated white blood cell count (>12.5), high C-reactive protein >115, positive blood cultures, magnetic resonance imaging/computed tomographic documented cord compression, and significant neurological deficits (e.g., 19–45%).

Results:

Surgical options include: decompressions, open versus minimally invasive biopsy/culture/irrigation, or fusions. Up to 75% of SEA involve the thoracolumbar spine, and 50% are located ventrally. Wound cultures are positive in up to 78.8% of cases and are often (60%) correlated with positive blood cultures. The most typical offending organism is methicillin resistant Staphylococcus aureus, followed by methicillin sensitive S. aureus. Unfortunately, the failure rates for nonoperative treatment of SEA remain high (e.g., 41–42.5%), contributing to significant morbidity (22% risk of permanent paralysis), and mortality (3–25%).

Conclusion:

The vast majority of studies advocated early surgery to achieve better outcomes for treating SEA; this avoids high failure rates (41–42.5%) for nonoperative therapy, and limits morbidity/mortality rates.