Osteomyelitis in Diabetic Foot Ulcers: Frequency and Associated Risk Factors at the National Diabetes Centre, Iraq

Technical Summary: Osteomyelitis in Diabetic Foot Ulcers at the National Diabetes Centre, Iraq

Problem Statement
Diabetic foot osteomyelitis (DFO) represents a severe complication of diabetic foot ulcers (DFU), significantly increasing the risk of prolonged antimicrobial therapy, hospitalization, and lower-extremity amputation. While the prevalence of diabetes in Iraq is high (over 13.9% of adults), evidence regarding the specific frequency of DFO and its independent risk factors within the Iraqi specialist-clinic population remains limited. Existing literature indicates substantial variation in reported frequencies and associated factors across different settings, necessitating localized data to improve diagnostic and management strategies.

Methodology
This study employed an analytical cross-sectional design conducted at the diabetic foot clinic of the National Diabetes Centre in Baghdad, Iraq, between February 1, 2025, and January 5, 2026.

• Participants: The study consecutively enrolled 208 adults with Type 2 diabetes and active foot ulcers. From an initial screening of 387 patients, 179 were excluded based on criteria such as Type 1 diabetes, age ≤20, lack of active ulcers, or incomplete records.
• Data Collection: Data were gathered via structured interviews, clinical examinations, and medical record reviews. Variables included demographics, anthropometrics, diabetes duration, glycemic control (HbA1c), comorbidities (hypertension, dyslipidemia, neuropathy, peripheral vascular disease), and ulcer characteristics (grade, location, duration, recurrence, cause).
• Diagnostic Criteria: DFO was defined as a clinically suspected contiguous bone infection supported by a positive bone/deep-tissue culture and/or compatible probe-to-bone and plain-radiographic findings. Bone histopathology and MRI were not routinely utilized due to availability constraints.
• Statistical Analysis: Binary logistic regression was utilized to identify factors independently associated with osteomyelitis, adjusting for potential confounders. Associations were assessed using chi-square tests, with statistical significance set at p < 0.05.

Key Results

• Frequency: Osteomyelitis was identified in 45 of the 208 participants, yielding a frequency of 21.6%.
• Demographics and Clinical Profile: The mean age was 60.9 years, with a mean diabetes duration of 16.88 years. The majority of patients had uncontrolled diabetes (83.2% with HbA1c > target), hypertension (68.3%), and dyslipidemia (59.6%).
• Independent Risk Factors: Multivariable logistic regression identified four factors significantly and independently associated with an increased risk of osteomyelitis:
  1. Recurrent Ulcers: Patients with recurrent ulcers were approximately 23 times more likely to have osteomyelitis (OR 23.32; 95% CI 7.47–72.82; p=0.001).
  2. Ulcer Duration: Patients with ulcers persisting for more than 3 months were 20 times more likely to have osteomyelitis compared to those with ulcers <1 month (OR 20.14; 95% CI 5.95–68.20; p=0.001).
  3. Hypertension: Hypertensive patients had a four-fold increased risk (OR 4.16; 95% CI 1.27–13.65; p=0.048).
  4. Neuropathy: Patients with neuropathy were three times more likely to develop osteomyelitis (OR 3.13; 95% CI 1.15–8.48; p=0.002).
• Ulcer Characteristics: The forefoot was the most common ulcer location (51%). Friction was the most frequent cause of ulceration (20.7%), though foreign bodies were notably associated with osteomyelitis cases. Grade 3, 4, and 5 ulcers showed a strong correlation with osteomyelitis presence.
• Microbiology: Among the 45 confirmed cases, Staphylococcus aureus was the most common pathogen (20%), followed by Pseudomonas species (17.7%) and Escherichia coli (11.1%). Methicillin-resistant Staphylococcus aureus (MRSA) was identified in 11.1% of cases.
• Laboratory Markers: Abnormal levels of CRP, ESR, and WBC were significantly associated with osteomyelitis (p < 0.001 for all).

Significance and Claims
The author positions this as the first study in Iraq to assess the frequency of osteomyelitis specifically among Type 2 diabetic patients with foot ulcers using bone culture combined with clinical and radiological criteria. The study claims to provide critical baseline data for a region where evidence has been scarce.

Key claims regarding clinical utility include:

• Diagnostic Utility: The study reinforces that the probe-to-bone test is an easy, non-costly, and highly specific method for diagnosing DFO. While the author notes that plain X-rays demonstrated good prognosis related to bone changes and destruction in the cases where they were positive, they explicitly acknowledge that systematic MRI and bone histopathology were not routinely available, which may have led to misclassification in some instances.
• Risk Stratification: The findings highlight that specific clinical histories—particularly recurrent ulcers, prolonged duration, hypertension, and neuropathy—serve as strong predictors for DFO, suggesting these patients require heightened surveillance.
• Microbiological Context: The identification of S. aureus as the predominant pathogen aligns with global trends but provides specific local prevalence data for Iraq, including MRSA rates.

The author maintains a modest tone regarding causality, acknowledging the cross-sectional design prevents the establishment of temporal relationships. They also note limitations regarding the single-center nature of the study, the lack of MRI/histopathology for all cases, and the potential for residual confounding. The study concludes that DFO is a difficult-to-diagnose but serious complication, emphasizing the need for early detection strategies targeting the identified high-risk factors.