Osteomyelitis and Septic Arthritis Flashcards
What is Osteomyelitis?
An inflammation or swelling of the bone tissue due to an infection
Can be Acute or Chronic
Can be:
1. Pyogenic (Suppurative)
Producing pus
Typically, bacterial
Acute or Chronic
- Non-Pyogenic (Non-Suppurative)
Fungal osteomyelitis
Skeletal syphilis
Tuberculous osteomyelitis
What is Pyogenic (Suppurative) Osteomyelitis?
Producing pus
Typically, bacterial
Acute or Chronic
What is Non-Pyogenic (Non-Suppurative) Osteomyelitis?
Fungal osteomyelitis
Skeletal syphilis
Tuberculous osteomyelitis
What may cause Osteomyelitis?
- A bacterial (Staphylococcus aureus) bloodstream infection
- M/c in infants and children
- affects long bones
- Femur > Tibia > Fibula
- Distal end > Proximal end
- In adults it involves the vertebral bones along the spinal column - A nearby infection due to
- a traumatic injury
- frequent medication injections
- a surgical procedure
- Diabetic patients who develop foot ulcers - Low immune system
- e.g Sickle cell disease or HIV
- immunosuppressive medications (e.g. chemotherapy or steroids)
Where abouts in the bone does osteomyelitis affect an infantile?
<8 months
neonates:metaphysis and/or epiphysis
Where abouts in the bone does osteomyelitis affect a child?
1 year to closure
metaphysis
Where abouts in the bone does osteomyelitis affect a child?
epiphyses and subchondral regions
What is the epidemiology of Osteomyelitis?
- M/C in younger children (2 – 12 years old)
- Can occur at any age.
- M/C in males than females
What are the signs and symptoms of Osteomyelitis?
- Fever
- Fatigue
- Pain and tenderness in the affected area
- Feeling unwell and irritability in infants who can’t express pain
- Swelling, warmth and redness of the affected area
- Difficulty moving joints near the affected area
- Difficulty bearing weight or walking
- A new limp
- Stiffness (with vertebral involvement)
What are the DDX of Osteomyelitis?
- Neuropathic osteoarthropathy
- Aseptic arthritis
- Acute fracture
- Recent surgery
- Ewing’s sarcoma
What is treatment and Management for Osteomyelitis?
- Medications
- Intravenous (IV) or oral antibiotics
- Monitoring of successive X-rays and blood tests
- Pain management
- Bed rest
- or restricted movement of the affected area
- Surgery
- may be necessary to drain infectious fluid, or to remove damaged tissue and bone
What are the complications of Osteomyelitis?
Complications:
- In untreated cases, Osteomyelitis becomes chronic with eventual formation of:
- Sequestrum
- Devascularisation of a portion of bone with necrosis and resorption of surrounding bone leaving a floating piece (Segment of dead/ necrotic bone)
- Develops after 30 days
- In some cases – sequestrum becomes encased in a thick sheath of periosteal new bone (Involucrum)
- May reside within marrow for long period - Involucrum
- Layer of living bone (bony collar or cloak) around necrotic bone as attempt to wall off infective process
- Thick sheath of periosteal new bone surrounding a sequestrum
- Laminated or spiculated periosteal reaction
- Develops after 20 days - Cloaca
- space in which dead bone resides
- Associated with chronic osteomyelitis
Complications:
- Other complications of Chronic Osteomyelitis include:
- Brodie’s Abscess
- Lucent, well-defined lesion with thick sclerotic rim
- Lucent tortuous channel extending towards growth plate prior to physeal closure
- Typically, in metaphysis or diaphysis of long bones:
- thick and dense cortex
- sinus tracts to skins - Fibrosarcoma
- Squamous cell carcinoma
What are radiological findings of Osteomyelitis?
- Soft tissue Swelling
- Earliest Sign
- Often in metaphyseal region
- Loss or blurring of normal fat planes - Cortical loss
- Bone destruction (Bony lysis) - Periostitis
- Periosteal reaction or thickening – laminated, solid, codman’s triangle
- May appear aggressive - Endosteal scalloping
- Loss of trabecular bone architecture
- Peripheral sclerosis
- Poss effusion in an adjacent joint
- Regional Osteopenia
Chronic Osteomyelitis
- Sclerosis
- cortical thickening
- Periosteal new bone formation
- Destruction
- sequestra
What is septic arthritis?
A destructive arthropathy caused by an inflammation due to hematogenous seeding of the synovial membrane from an intra-articular infection e.g.
- infected source elsewhere in the body (wound infection)
- direct, contiguous extension from osteomyelitisadjacent to the joint
Early imaging is necessary to:
- detect any joint effusion due to an intra-articular infection
- check for any associated osteomyelitis
Subdivided into:
1. pyogenic (septic) arthritis
- due mostly toStaphylococcalandGonococcalorganisms
- HALLMARK: destruction of the articular cartilage and long, contiguous segments of the adjacent articular cortexfrom proteolytic enzymes released by the inflamed synovium.
2. non-pyogenic arthritis
- due mostly to infection withMycobacterium tuberculosis
What is the epidemiology of septic arthritis?
- All age groups
- 50% <3 yoa
- M = F