Etiology, Pathogenesis, and Clinical Manifestations of Osteomyelitis

Introduction

Osteomyelitis is an infection of the bone, typically caused by bacteria. It can develop through direct contamination, hematogenous spread, or as a result of contiguous infections. Understanding the clinical features and classification of osteomyelitis is crucial for prompt diagnosis and effective treatment.

Etiology and Pathogenesis

Causes

• Staphylococcus aureus (most common pathogen)
• Other bacteria such as Pseudomonas aeruginosa and Streptococcus species
• Fungal infections in immunocompromised individuals

Pathogenesis

The infection begins with bacterial invasion, triggering an inflammatory response. This leads to bone necrosis, abscess formation, and possible systemic complications.

Clinical Manifestations

Symptoms

• Pain and tenderness at the affected site
• Swelling and erythema
• Fever and malaise

Signs

• Restricted movement in the affected limb
• Presence of draining sinuses in chronic cases
• Localized warmth over the infection site

Classification

• Acute osteomyelitis: Sudden onset with systemic symptoms
• Chronic osteomyelitis: Persistent infection with bone sequestra formation
• Hematogenous osteomyelitis: Spread through the bloodstream

Radiologic and Morphologic Features

Diagnostic imaging plays a crucial role in identifying osteomyelitis:

• X-ray: Shows osteolysis and periosteal reaction
• MRI: Detects marrow involvement
• CT scan: Useful for evaluating bone destruction

Complications

• Pathologic fractures
• Septic arthritis
• Systemic sepsis

Conclusion

Early detection and appropriate treatment are key to managing osteomyelitis effectively. Clinical evaluation, radiologic imaging, and microbiological testing guide the approach to therapy.