Microbiology - MSK infections 1 Flashcards
What is osteomyelitis ?
An infection of the bonemedullary cavity, usually located in one of the long bones.
What are the 6 main types/causes of osteomyelitis ?
- Open fractures
- Diabetes/ Vascular insufficiency
- Haematogeneous osteomyelitis
- Vertebral osteomyelitis
- Prosthetic joint infection
- Specific hosts and pathogens
What is the signs that an open fracture has become infected ?
Non-union and poor wound healing
What is the early management for infected open fractures ?
Aggressive debridement, fixation and soft tissue cover
Diabetes/ vascular insufficiency can lead to complications such as ulcers, these ulcers can become infected which can then lead to deeper infection of the bone (osteomyelitis), what are the investigations you would do to try and diagnose osteomyelitis in this situation ?
- Probe to bone test - 1st choice
- If positive then do a plain radiograph
- If this shows signs of osteomyelitis then bone biopsy for histology anf culture done
What is the management plan for osteomyelitis occurring due to infected ulcers ?
- Debridement
- Antimicrobials
What are the risk factors for developing haemategenous osteomyelitis ?
- Prepubertal children
- PWID - (people who inject drugs)
- Central lines/ dialysis/ elderly
What are the associated causes of vertebral osteomyelitis ?
Mostly haematogeneous
May be associated with:
- Epidural abscess
- Psoas abscess
May be associated with:
- PWID
- IV site infections
- GU infections
- SSTI
- Post operative
What are the clinical signs/symptoms of vertebral osteomyelitis ?
- 50 % have a fever
- 90 % insidious pain and tenderness
- 15% neurological signs/ symptoms
- 90% raised inflammatory markers
- Less than 50% raised white cell count
What is done to diagnose vertebral osteomyelitis ?
MRI, Ga-67 scan, biopsy (fine-needle aspiration biopsy)
What is the treatment of vertebral osteomyelitis ?
- Drainage of large paravertebral/ epidural abscesses
- Antimicrobials for 6 weeks
What is potts disease ?
Pott’s disease is a form of tuberculosis that occurs outside the lungs whereby disease is seen in the vertebrae.Tuberculosis can affect several tissues outside of the lungs including the spine, a kind of tuberculous arthritis of the intervertebral joints.
What are the risk factors for developing infections in prosthetic joints ?
- Rheumatoid arthritis
- Diabetes
- Malnutrition
- Obesity
What type of infection could be shown here ?
Prosthetic joint infection
How is prosthetic joint infections diagnosed ?
- Culture..perioperative tissue (multiple)- if same organism grows from multiple samples –increases significance
- Blood culture
- CRP
- Radiology
