Pathophysiology of chronic bacterial osteomyelitis. Why do antibiotics fail so often?

Area of Science:

• Orthopedics
• Infectious Diseases
• Microbiology

Background:

• Chronic bacterial osteomyelitis presents a significant challenge due to bacteria's ability to evade host defenses and therapeutic agents.
• Bacteria employ various mechanisms to persist, including adherence to bone matrix and orthopedic implants, intracellular sequestration, biofilm formation, and metabolic dormancy.

Purpose of the Study:

• To summarize the pathophysiology of chronic bacterial osteomyelitis.
• To elucidate bacterial strategies for evading host defenses and antibiotics.
• To highlight the impact of orthopedic implants and antibiotic resistance on treatment outcomes.

Main Methods:

• This is a review article, synthesizing existing research on the pathophysiology of chronic bacterial osteomyelitis.
• Key mechanisms of bacterial evasion, host response, and implant-related factors are discussed.

Main Results:

• Bacteria adhere to bone and implants via fibronectin and other proteins.
• Evasion tactics include intracellular hiding, biofilm formation (slimy coat), and slow metabolic rates.
• Orthopedic implants can impair local immune cell function, reducing bacterial killing capacity.
• Osteolysis results from bacterial components interacting with immune cells and cytokine production.
• Increasing antibiotic resistance in Staphylococcus aureus and Staphylococcus epidermidis complicates treatment.

Conclusions:

• Bacterial persistence in osteomyelitis is multifactorial, involving adherence, evasion, and host-related factors.
• The presence of orthopedic implants exacerbates the local immune response defect.
• Rising antibiotic resistance necessitates integrated treatment approaches.
• Combined medical and surgical management by orthopedic surgeons and physicians is recommended for improved outcomes.