Related Subjects:
| Monoarticular arthritis
| Polyarticular arthritis
| Rheumatoid arthritis
| Gout
| Pseudogout
| Septic Arthritis
| Osteomyelitis
|Systemic Lupus Erythematosus (SLE)
|Enteropathic Spondyloarthritis
|Reactive Arthritis
In patients with Sickle cell disease - Staph aureus and salmonella are the most commonly involved organisms
About
- Infection of bone which can lead to pain, deformity and chronic disease if untreated
- A surgical, sometimes paediatric, microbiological emergency
Aetiology
- Differing picture in adults and children
- Association with sickle cell disease commonly asked about
- Microbial source from the skin, or another infective source
Microbiology
- Staphylococcus aureus 85%
- E.Coli (IVDU/Urosepsis)
- Pseudomonas (IVDU/Urosepsis)
- Klebsiella (IVDU/Urosepsis)
- Salmonella (sickle cell)
- Haemophilus influenza (neonates)
- Group B Streptococcus (neonates)
- Fungal immunocompromised
Types
- Direct from open fracture, skin wound, post op
- Indirect: blood spread from infection elsewhere
Adult disease
- In those over the age of 45 the vertebral bodies are more likely infected
- This is due to changes in blood flow with spinal osteomyelitis
- Tuberculosis still remains prevalent in certain groups
Childhood disease
- Haematogenous spread usually to seed long bone metaphyses
- Infants - Staph aureus, Streptococcus agalactiae, Escherichia coli
- After 1st year - S. aureus, Streptococcus pyogenes, Haemophilus influenzae
- Haemophilus influenzae falling due to new vaccination policies
Risks
- Open fractures, prostheses, Diabetes, Alcoholism, Chronic steroids
- AIDS, Immunosuppression, Sickle cell
- IV drug abuse - haematogenous spread to vertebrae
Clinical
- Toxic, Febrile and rigors, Localised Bone pain, tenderness, warmth, swelling
- Children can have just vague symptoms for weeks however many hold the joint
- Can be simply also a PUO and suspicious organism
Investigations
- Plain X-Ray unreliable (will take 2-4 weeks for demineralization of bone)
- Tissue swelling, demineralization
- Sequestra (necrotic bone with granulation tissue)
- Involucrum (periosteal new bone around the sequestra)
- Brodie's abscess a small oval cavity in metaphysis of long bone
- CT: useful to depict margins. See findings on X Ray
- MRI (Gold standard) most sensitive and specific and is able to identify soft-tissue/joint complications. Shows bone marrow oedema.
- USS (may show periosteal lifting)
- Three phase bone scan
- Blood cultures are positive in 50 per cent of cases of acute osteomyelitis
- CRP and ESR and WCC are typically raised
- Need to obtain pus by open surgery and biopsy or needle aspiration before starting antibiotics ideally
Differential
- Synovitis
- Trauma and fracture
- Bone cancer
Management (Take microbiological advice on all cases)
- Based on results of culture and local sensitivities
- Flucloxacillin and Fusidic acid for 4–6 weeks with IV initially.
- Patients may need a central line or long line
- Specific Organisms and antibiotics
- Staph aureus - IV Penicillin or Vancomycin + Rifampicin
- Streptococci - Penicillin
- Anaerobes - Clindamycin or Metronidazole
- Pseudomonas - Ciprofloxacin
- Surgical Management
- Debridement and removal of necrotic tissue and drainage
- Replacement of dead space with tissue flaps or bone grafts
- Internal/external fixation. Amputation may be needed
References