Bone Infection Flashcards
What is Osteomyelitis
List 4 types
Bony inflammation almost always due to infection
- Bacterial (most common) - pyogenic osteomyelitis.
- Tuberculous osteomyelitis
- Skeletal syphilis
- Fungal osteomyelitis
Most common age and gender in osteomyelitis
- Between ages 2 - 12 years (can affect any age)
- More common in males
Most common organism in osteomyelitis?
First line antibiotic treatment?
Staphylococcus aureus
Flucloxacillin
Location of osteomyelitis within bone varies with age (due to changing blood supply)
State the affected region of bone in neonates vs children vs adults
Neonates : metaphysis and / or epiphysis
Children : metaphysis
Adults : epiphyses and subchondral regions
Acute osteomyelitis in childhood most commonly affects which bone (2)
femur, tibia
List 3 x-ray features of acute osteomyelitis in childhood
- Sequestration frequent
- Periosteal elevation (with disruption of periosteal blood supply)
- Small single / multiple osteolytic areas in metaphysis
List 2 complications of acute osteomyelitis in adulthood
- soft-tissue abscess
- pathological fractures
List 4 risk factors for acute osteomyelitis in adulthood
- IV drug use
- Previous trauma
- Immunosuppressed state
- Diabetes
- joint involvement common
Gold star imaging for acute osteomyelitis
MRI - most sensitive and specific, is able to identify soft-tissue/joint complications
Spinal Discitis is also known as what?
What is this?
Infective spondylosis
Infection involving the intervertebral disc and adjacent vertebrae
Most common age affected by spinal discitis
Equal distribution among ages
Most common organism in spinal discitis
Incl 2 others
- Staphylococcus aureus (most common)
- Streptococus viridans (IVDU & immunocomprimised)
- Gram negative organisms
- Mycobacterium tuberculosis
Which spinal level does discitis most commonly occur?
Can occur anywhere but is most common in lumbar levels
Gold star imaging for spinal discitis
MRI - very high sensitivity and specificity
Also useful in ddx between pyogenic infection, TB/fungal infection or neoplasia
What age group is most commonly affected by Tuberculosis osteomyelitis?
children< 5 years (rare in adults)
Which bones are most commonly affected in TB osteomyelitis
Which specific location of bone is affected?
Bones (can be any):
- femur, tibia, small bones of hand + foot (most common)
Site within bone
- Metaphysis (typically) with transphyseal spread
- Epiphysis with spread to joint/ spread from adjacent affected joint
What is the other name given to Pott Disease and what is this?
Tuberculous spondylitis - refers to vertebral body and intervertebral disc involvement with tuberculosis
What spinal levels are most commonly affected in Potts disease
Which region of the vertebrae is affected
Spinal level:
- Upper lumbar + lower thoracic spine (L1 most common)
- Typically more than one vertebra affected
Region:
- Vertebral body (82%)
- With predilection for anterior part adjacent to superior / inferior endplate
Gold star investigation for spinal discitis
Incl 3 features seen
MRI (CT with contrast is second)
Features:
- Irregularity of endplate and anterior vertebral bodies,
- Bone marrow oedema
- Well circumscribed fluid collections with well defined center margins
