How nonbacterial osteomyelitis could be discriminated from tuberculosis in the early stages: the simple algorithm

Area of Science:

• Bone Diseases
• Inflammatory Conditions
• Infectious Diseases

Background:

• Chronic nonbacterial osteomyelitis (CNO) and tuberculous osteomyelitis (TBO) are chronic inflammatory bone diseases with overlapping clinical and radiological presentations.
• Despite similar appearances, CNO and TBO have distinct etiologies, pathogenesis, treatment strategies, and prognoses.
• Accurate differentiation between CNO and TBO is crucial for appropriate patient management and outcomes.

Purpose of the Study:

• To identify and evaluate clinical and laboratory features that can effectively discriminate between chronic nonbacterial osteomyelitis (CNO) and tuberculous osteomyelitis (TBO).
• To develop provisional diagnostic criteria to aid in differentiating these two bone conditions.
• To assess the diagnostic utility of routine blood tests and imaging in distinguishing CNO from TBO.

Main Methods:

• A comparative study involving 124 patients (91 with CNO, 33 with TBO).
• Analysis of routine blood tests including WBC, platelets, ESR, C-reactive protein, and hemoglobin.
• Evaluation of imaging findings, sensitivity, specificity, AUC-ROC analysis, and odds ratios to determine discriminatory power of variables.

Main Results:

• TBO patients exhibited fewer bone foci, later onset age, less frequent articular involvement, lower hemoglobin, and higher leukocyte bands compared to CNO patients.
• TBO showed a higher incidence in males and was less commonly associated with spine, foot, or clavicula involvement.
• Key discriminators included negative bone microbiota tests, clavicula involvement, number of foci, WBC count, neutrophil bands, lymphocyte percentage, and CRP levels.

Conclusions:

• Specific clinical and laboratory findings, alongside imaging characteristics, can help differentiate between chronic nonbacterial osteomyelitis (CNO) and tuberculous osteomyelitis (TBO).
• Provisional diagnostic criteria were developed, incorporating negative bone microbiota tests and a combination of clinical and laboratory parameters.
• Bone biopsy with microbiology assessment remains essential for definitive diagnosis, particularly for monofocal CNO.