What are the symptoms and treatment of osteomyelitis?

Symptoms of Osteomyelitis

The classic triad of fever, pain, and diminished mobility occurs in just over 50% of acute hematogenous osteomyelitis cases, making clinical diagnosis challenging and often requiring a high index of suspicion based on risk factors and physical findings. 1

Clinical Presentation

General Symptoms

• Fever is common in infectious osteomyelitis, often accompanied by systemic symptoms such as chills 2
• Localized bone pain at the site of infection, which may be severe and persistent 3
• Diminished mobility or inability to bear weight on the affected limb 1
• Swelling and erythema overlying the infected bone 1

Specific Clinical Signs

• "Sausage toe" (red, swollen digit) suggests underlying osteomyelitis in the foot 1
• Visible or palpable bone through an ulcer strongly indicates osteomyelitis, particularly in diabetic foot infections 1
• Chronic non-healing ulcer (>6 weeks despite appropriate care) should raise suspicion for underlying bone infection 1
• Subperiosteal abscess may develop from metaphyseal spread, leading to bone ischemia and necrosis 1

Laboratory Findings

• Significantly elevated inflammatory markers: C-reactive protein (CRP) >2.0 mg/dL or erythrocyte sedimentation rate (ESR) ≥40 mm/hour 1, 2
• Leukocytosis: White blood cell count ≥12,000 cells/mm³ 1
• Bacteremia may be present in hematogenous cases 2
• Inflammatory markers are elevated in approximately 73.6% of cases 4

Age-Specific Considerations

Pediatric Patients

• The classic triad (fever, pain, diminished mobility) is present in only slightly more than 50% of acute cases 1
• Neonates and infants may present with septic arthritis secondary to osteomyelitis spread into adjacent joints 1
• Children <2 years are more likely to have septic arthritis than osteomyelitis 1
• Children 2-10 years show slightly higher rates of osteomyelitis versus septic arthritis 1

Adult Patients

• Presentation may be more subtle, particularly in chronic cases 5
• Diabetic patients often present with foot ulcers overlying bony prominences 1
• Post-surgical or post-traumatic osteomyelitis (57.3% combined) is more common than hematogenous spread (23%) 4

Common Pitfalls in Recognition

Do not rely solely on the classic triad, as it is absent in nearly half of cases 1. Instead, maintain high suspicion when:

• Any deep or extensive ulcer overlies a bony prominence 1
• A wound fails to heal after 6 weeks of appropriate care 1
• Unexplained elevation of inflammatory markers or WBC count occurs 1
• Post-surgical sternal wounds show persistent drainage or instability 2

Most Common Causative Organisms

• Staphylococcus aureus (including methicillin-susceptible strains at 29.6%) is the predominant pathogen across all age groups 1, 6, 4
• Group B streptococcus in neonates 1
• Kingella kingae in children <4 years 1
• Salmonella species in patients with sickle cell disease 1

Anatomic Distribution

• Tibia (24.1%) and femur (21.8%) are most commonly affected in adults 4
• In children, metaphyseal regions of long bones are typical sites 1
• Knee and hip joints are most common for associated septic arthritis 1

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Treatment Overview

Antibiotic Therapy Duration

• Soft-tissue infection only: 1-4 weeks depending on severity 1
• Bone involvement with complete surgical resection: 2-5 days post-operatively 1
• Bone involvement with residual infected tissue: 4-6 weeks minimum 1, 7, 8
• Chronic osteomyelitis or failed initial therapy: May require several weeks longer than acute cases 5

Surgical Indications

• Subperiosteal collections or abscesses 1
• Bone necrosis or sequestrum formation 1
• Failure to respond to initial antibiotic management 1
• Septic arthritis requires arthrotomy, irrigation, and debridement 1
• Surgery combined with antibiotics significantly reduces relapse rates (p<0.0001) 4

Route of Administration

• Initial parenteral therapy is traditional, particularly for severe infections 1
• Oral antibiotics with good bioavailability (fluoroquinolones, clindamycin, linezolid) may be equally effective after initial parenteral therapy 1, 9
• Intravenous administration should be given slowly over 30-60 minutes to minimize vein irritation 8