here is a small brief presentaion of osteomyelitis

1. Osteomyelitis

2. Definition
• Osteomyelitis is an infection of the bone; it occurs following hematogenous
(seeded from a remote source) or exogenous (expansion from nearby tissue)
spread of pathogens.

3. Epidemiology
• Incidence: ∼ 20 per 100,000
• Hematogenous osteomyelitis
-More common in children and adolescents
-Incidence is increasing in adults, driven by a rise in vertebral osteomyelitis
• Exogenous osteomyelitis: more common in adults

4. Etiology
• Hematogenous osteomyelitis (endogenous osteomyelitis): caused by hematogenous
dissemination of a pathogen
• Exogenous osteomyelitis: caused by a spread of bacteria (typically multiple pathogens)
from the surrounding environment
-Posttraumatic: infection following deep injury (penetrating injury, open fractures,
severe soft tissue injury)
Contiguous: spread of infection from adjacent tissue
• Secondary to infected foot ulcer in patients with diabetes
• Iatrogenic (e.g., postoperative infection of a prosthetic joint implant)

5. Pathogens
• S.aureu (MCC)
• S.epidermidis
• Streptococci
• Pseudomonas aeruginosa
• Enterobacteriaceae eg.(Salmonella, klebsiella)
• M.tuberculosis
• Pasturella
• Fungi

6. Clinical picture
• Acute osteomyelitis and subacute osteomyelitis
• Onset: within days or weeks; associated with acute bone inflammation
• Duration: < 2 weeks (acute) or 2–6 weeks (subacute) [3][8]
• Symptoms: pain at the site of infection; in patients with peripheral neuropathy the pain
may be mild or absent, symptoms of underlying disease
• Possible localized findings: point tenderness, swelling, redness, warmth
• Possible systemic findings: malaise, fever, chills

7. • Chronic osteomyelitis
• Onset: develops slowly (over months or years) following acute infection
• Associated with: avascular bone necrosis and sequestrum formation (necrotic bone
fragment that has become detached from the original bone) [9]
• Duration: typically > 6 weeks
• Symptoms: recurrent pain lasting weeks to months, maybe cyclical
• Possible localized findings
• Swelling, redness
• Deformity
• Impaired healing of overlying wounds
• Local sinus tract formation, perhaps draining pus
• Positive probe-to-bone test [10]
• Systemic findings: typically absent; may include low-grade fever, malaise

9. Diagnostics (for non-vertebral osteomyelitis)
• Approach
• Signs of sepsis present: Start management of sepsis without waiting for diagnostic test
results.
• Routine studies:CBC, inflammatory markers, blood cultures, and an x-ray
• Imaging:
• X-ray: low sensitivity and specificity for osteomyelitis
• MRI with and without IV gadolinium: most sensitive study
• Imaging findings and blood cultures inconclusive: Consider bone biopsy with cultures to
confirm the diagnosis.

10. Treatement
• All patients
• Provide pain management and supportive treatment to optimize bone healing.
• Admit for IV antibiotics
• Hematogenous osteomyelitis: Identify and treat the underlying infection.
• Surgery consultation

11. DD
• Septic arthritis
• Infection of the joint (in contrast to osteomyelitis, involvement of the metaphysis is
rare)
• May occur secondary to osteomyelitis in infants
• Bone tumors (e.g., Ewing sarcoma, osteoid osteoma)
• Avascular bone necrosis
• Benign bone tumors (e.g., bone cyst)
• Fracture

12. Septic arthritis
• Infection of the joint space, which can occur in a native joint or a prosthetic
joint.

13. Etiology
• Hematogenous spread (most common)
• From a distant site (e.g., abscesses, wound infection, septicemia)
• Disseminated infection (e.g., gonorrhea)
• Direct contamination
• Iatrogenic (e.g., joint injection, arthrocentesis , arthroscopy ) [1]
• Trauma (e.g., open wounds around the joint , penetrating trauma)
• Contiguous spread (e.g., septic bursitis, osteomyelitis)

14. Causative organisms
• Staphylococcus aureus
• Most common in adults and children > 2 years
• Frequently found in patients with arthritis following invasive joint procedures [2]
• K. kingae: most common in infants and children ≤ 2 years [3]
• Streptococci
• N. gonorrheae
• Gram-negative rods esp. E. coli and P. aeruginosa
• S. epidermidis
• H. influenzae
• M. tuberculosis and atypical mycobacteria
• B. burgdorferi (Lyme disease)

15. Clinical features
• Acute onset
• Classical triad of fever, joint pain, and restricted range of motion
• Arthritis
• Usually monoarticular
• Most commonly affected joints: knees (followed by hip, wrists, shoulders, and ankles)
• Joints are swollen, red, warm, and painful.

16. Subtypes & variants
• Prosthetic joint infection
• Bacterial coxitis
• Gonococcal arthritis
• Lyme arthritis

17. Diagnostics
• Approach
• Any red, painful joint with a reduced range of motion should be considered infectious
until proven otherwise
• All patients
• Arthrocentesis with synovial fluid analysis and culture (gold standard)
• Blood cultures in patients with fever or acute onset of symptoms
• X-rays of the affected joint

18. • Suspected gonococcal arthritis
Additional cultures and PCR testing of swabs from mucosal sites are
recommended.
• Suspected PJI
Diagnostic criteria for PJIs can be used alongside clinical features to establish a
diagnosis.
Advanced imaging (e.g., MRI, nuclear medicine studies) may be necessary.

20. • Arthrosentesis
• Synovial fluid analysis (SFA) in septic arthritis
• Appearance: often yellow-green and turbid (nonspecific)
• Cell count: ↑WBC count (e.g., > 50,000/mm3) ,Neutrophil (PMN) dominance of > 90%
• Glucose levels: lower than blood glucose levels
• Gram stain & culture (A negative Gram stain does not rule out septic arthritis).
• Laboratory studies
• Blood cultures (for aerobic and anaerobic organisms)
• CBC, CRP, ESR: Leukocytosis and elevated inflammatory markers may be seen (nonspecific).
• Culture and PCR testing for N.gonorrhoeae
• BMP and liver chemistries: to guide antibiotic selection
• Imaging

21. Treatment
• Native joint infection
• Serial therapeutic arthrocentesis
• Empiric antibiotic therapy guided by Gram stain and clinical features
• Targeted antibiotic therapy once antibiotic sensitivities are known
• Prosthetic joint infection
• Pathogen specific antibiotic
• Orthopedic & infectious disease consultation

22. Complications
• Joint destruction
• Osteomyelitis
• Sepsis
• Children: growth arrest