Osteomyelitis

• What is osteomyelitis?

  Inflammation in a bone & bone marrow

  Can be acute or chronic (acute = usually single organism, chronic = usually polymicrobial)
• What are the most common causative pathogens of osteomyelitis?

  Staph aureus

  Coagulase-negative staphylococci
• What is haematogenous osteomyelitis?

  When a pathogen is carried through the blood & seeded in the bone

  Most common mode of infection
• Other than haematogenous osteomyelitis, how else can osteomyelitis occur?

  Direct contamination

  E.g. at a fracture site or during an orthopaedic operation
• What are the RFs for osteomyelitis?

  Open fractures

  Orthopaedic operations (esp with prosthetic joints -> BIG PROBLEM)

  Diabetes (esp diabetic foot ulcers)

  Peripheral arterial disease

  IVDU

  Immunosuppression

  Extremes of age

  Malignancy

  Sickle cell disease (can cause infarction of the bone & bone marrow -> secondary infection)
• What are the signs & symptoms of acute osteomyelitis?

  Symptoms develop over a few days

  Painful, hot, red, swelling of the soft tissue surrounding affected bone

  Fever

  Malaise

  Pain at rest
• What are the signs & symptoms of chronic osteomyelitis?

  Lengthy history of pain

  Persistently draining sinus tract or wound

  Soft tissue damage

  Presence of RFs (diabetes, peripheral vascular disease)
• What are the DDx of osteomyelitis?

  Septic arthritis

  Ewing sarcoma

  Cellulitis

  Gout
• What is Ewing sarcoma?

  Rare bone cancer affecting children
• What are the Inx for osteomyelitis?

  Obs

  Full Hx & examination

  Bloods (FBC, CRP, cultures, blood gas)

  X-rays

  MRI (gold standard)

  CT

  Cultures for pus, bone

  Bone biopsy
• What are the potential signs of osteomyelitis on XR?

  Periosteal reaction (changes to the surface of the bone)

  Localised osteopenia (thinning of the bone)

  Destruction of areas of bone
• What is the management of osteomyelitis?

  Surgical debridement of infected bone & tissues

  Abx (6 weeks of flucloxacillin (of clindamycin, vancomycin/teicoplanin), possibly with rifampicin or fusidic acid for first 2 wks)

  Chronic osteomyelitis = 3 months or more of Abx

  Osteomyelitis associated with prosthetic joints -> may need complete revision surgery to replace prosthesis
• What are the possible complications of osteomyelitis?

  Amputation

  Infection recurrence
• Pathophys - osteomyelitis

  Haematogenous seeding of the infection

  Spread from adjacent soft tissues or joints

  Direct inoculation of infection into the bone due to wound contamination during trauma or surgery