Osteomyelitis Signs and Symptoms

• Osteomyelitis is an acute or chronic inflammation of the bone due to an infection resulting from hematogenous spread, contiguous spread from soft tissues & joints to bone, or direct inoculation into bone from surgery or trauma
  • Infection is generally due to a single microorganism but polymicrobial infections may also occur

Common Pathogens in Osteomyelitis

Acute Hematogenous Osteomyelitis (AHO)

• S aureus is the most common etiologic agent in children & adults
  • Children w/ community-acquired Methicillin-resistant S aureus (CA-MRSA) infection are more likely to have prolonged fever & be hospitalized for longer periods than children infected w/ Methicillin-sensitive S aureus (MSSA)
  • Children w/ Methicillin-resistant S aureus infection are more likely to have multiple foci of infection as well as subperiosteal & intraosseous abscesses

• Other causes of acute hematogenous osteomyelitis in children include Streptococcus pneumoniae, S pyogenes, Kingella kingae; rarely, Escherichia coli & other gram-negative enteric bacilli, Pseudomonas aeruginosa, Haemophilus influenzae type B, anaerobes
• IV drug abusers are more prone to infections by P. aeruginosa, Serratia marcescens, S aureus, Salmonella spp & fungal organisms
• Fungi may be the cause of osteomyelitis in neonates, patients who are immunocompromised eg w/ prolonged neutropenia, those w/ chronic granulomatous disease, catheter-related fungemia, or are in geographic locations indigenous for certain fungal diseases

Contiguous-Infection Osteomyelitis

• Among patients w/o generalized vascular insufficiency, S aureus is most frequently isolated from bone, but multiple pathogens may also be isolated including gram-negative bacilli & anaerobes
• Among patients who have generalized vascular insufficiency, esp those w/ DM, multiple pathogens are usually isolated from bone, most commonly coagulase-positive & negative staphylococci,Streptococcus spp, Enterococcus spp, gram-negative bacilli & anaerobes
• Anaerobic organisms are common in patients w/ risk factors including surgery, trauma, DM, decubitus ulcers, human bites, chronic otitis media or sinusitis, dental infection, prosthetic devices, fibrous dysplasia of the bone

Vertebral Osteomyelitis

• S aureus is the most frequently isolated pathogen
• Spondylitis is the most common form of Mycobacterium tuberculosis musculoskeletal infection & should be suspected if symptoms & x-rays indicate chronic infection
• E coli may be an etiologic agent in adults esp those w/ a history of recent urinary tract infection or instrumentation
• IV drug abusers are more prone to infections due to P aeruginosa, S aureus, Serratia spp, Klebsiellaspp, Enterobacter spp, or Candida spp

• Fever
• Inflammatory findings of erythema, warmth, pain, & swelling over the involved area
• Draining sinus tracts over affected bone
• Limited movement of affected extremity
• Pain in the chest, back, abdomen or leg, & tenderness over involved vertebrae in patients w/ vertebral osteomyelitis
• Anorexia, vomiting, malaise

• Chronic wounds w/ exposed bone, tissue necrosis, underlying open fractures or underlying internal fixation
• Advanced age
• Diabetes mellitus (DM)
• Immunosuppression
• IV drug abuse
• Organ transplantation
• Malnutrition
• Cancer
• Renal or hepatic impairment
• Chronic hypoxia
• Peripheral vascular disease
• Radiation fibrosis
• Neuropathy
• Tobacco consumption >2 packs/day