This document discusses different types of bone infections seen in musculoskeletal radiology. It describes osteomyelitis as bacterial infection of bone that most commonly affects the long bones of children. Pott's disease refers to tuberculosis infection of the spine that causes vertebral body destruction. Congenital infections like rubella and syphilis can result in characteristic radiographic findings in newborns such as celery stalking of the metaphysis.
4. Refers to bony inflammation that is almost
always due to infection, typically bacterial
Incidence :
• Osteomyelitis can occur at any age, in
those without specific risk factors it is
particularly common between the ages of
2-12 years of age and is more common in
males
5. Etiology :
Bacteria pass through nutrient vessels to
metaphyses where organisms proliferate,
metaphyseal inflammatory reaction
progresses to edema, pus, necrosis,
thrombosis.
In older children, the cartilaginous growth
plate becomes avascular and acts as a
barrier to epiphyseal extension.
6.
7. Three routes of infection are recognized :
• Hematogenous route (most common in
pediatrics)
• Direct inoculation
• Local extension from contiguous infection
8. • Children (unifocal) : Staphylococcus (85%),
Streptococcus (10%)
• Neonates (multifocal) : Streptococcus,
Staphylococcus
• Immunocompromised adults : short bones of
hand and feet : Staphylococcus
• Drug addicts : Pseudomonas (85%), Klebsiella
• Sickle cell disease : Salmonella
9. Location :
• Tubular bones with most rapid growth and
largest metaphysis are most commonly affected,
75% : femur > tibia > fibula; distal end >
proximal end
• Flat bones are less frequently infected, 25% :
vertebral bodies, iliac bones
• Neonates : metaphysis and/or epiphysis
• Children : metaphysis
• Adults : epiphyses and subchondral regions
11. Plain Radiography :
• Soft tissue swelling :
• Earliest sign
• Often in the metaphyseal region
• Loss or blurring of normal fat planes
• Regional osteopenia
• Cortical loss , 5 to 7 days after infection,
bone destruction
• periosteal reaction / thickening
18. In untreated cases eventual
formation of :
Sequestrum :
• Devascularization of a portion of bone with
necrosis and resorption of surrounding
bone leaving a floating piece.
• In some instances the sequestrum
becomes encased in a thick sheath of
periosteal new bone known as an
involucrum dead bone resides.
19. In untreated cases eventual
formation of :
Involucrum :
Thick sheath of periosteal new bone
surrounding a sequestrum.
Cloaca :
Cortical defect that drains purulent and
necrotic material.
24. Chronic Osteomyelitis :
Brodie's abscess :
• Lucent well-defined lesion with thick sclerotic
rim
• Lucent tortuous channel extending toward
growth plate prior to physeal closure
(pathognomonic)
• Typically in metaphysis or diaphysis of long
bones
• Thick and dense cortex
• Sinus tracts to skin
27. Sclerosing osteomyelitis of Garre:
• A specific type of chronic osteomyelitis
• It mainly affects children and young adults
• It typically affects the mandible and is
commonly associated with an odontogenic
infection resulting from dental caries
28. Sclerosing osteomyelitis in a 10-year-old boy, CT
scan shows diffuse sclerotic changes with
expansion of the left mandibular body (arrows),
note the diffuse soft-tissue swelling (arrowheads)
29. Coronal CT in a 7-year-old girl with sclerosing
osteomyelitis demonstrates osseous sclerosis,
remodelling, periosteal new bone (arrowhead), and
soft tissue swelling (arrow)
30. MRI :
• Bone marrow hypointense on T1 +
hyperintense on T2 (water-rich inflammatory
tissue)
• Post contrast enhancement of bone marrow,
abscess margins, periosteum and adjacent
soft tissue collections
32. Nuclear Medicine :
Ga-67 scans :
• 100% sensitivity
• Increased uptake 1 day earlier than for Tc-
99m MDP
• Gallium helpful for chronic osteomyelitis
33. Static Tc-99m Diphosphonate :
• 83% sensitivity
• Radionuclide images of the region of
interest during an angiographic phase
(blood flow phase) , a blood pool phase
(tissue phase) and a delayed phase
• There is no osteomyelitis without abnormal
radionuclide uptake on the images
obtained during the delayed phase
34. b) Pott’s Disease :
1.Incidence
2.Radiographic Features
3-Differential Diagnosis
35. Incidence :
-Also known as tuberculous spondylitis
-Refers to vertebral body and intervertebral
disc involvement with tuberculosis
Brucellosis can present as granulomatous
osteomyelitis of the spine that can be
difficult to distinguish from TB
36. Radiographic Features :
1. Bone destruction is prominent, more prolonged
onset than with pyogenic bone destruction
2. Loss of disc height, 80% (affects intervertebral
discs, but mets no)
3. Gibbus deformity : anterior involvement with
normal posterior vertebral bodies (Kyphosis)
4. Vertebra plana or pancake vertebra (vertebral
body has lost almost its entire height anteriorly
and posteriorly)
5. Involvement of several adjacent vertebral
bodies with disk destruction
6. Large paraspinous abscess
7. Extension into psoas muscles (psoas abscess)
45. Differential Diagnosis :
-From non-specific infections :
a) Site :
-Lumbar vertebrae are more affected in non-
specific infections
-T.B. : Cervical , dorsal then lumbar
b) Course :
-Acute with non-specific and prolonged in T.B.
c) Soft tissue mass , collapsed vertebrae :
-More with T.B.
d) Sclerosis :
-More with non-specific infections
46. Incidence :
-Rubella, bone changes in 50% of patients
-Syphilis, musculoskeletal involvement is
much more common, 95% of the time
Congenital Infections
47. Radiographic Features :
• Celery stalking of metaphysis with
longitudinally aligned linear bands of
sclerosis
• Periosteal reaction : *Absence in rubella
*Prominent in syphilis
• Rubella : delayed appearance of
epiphyses
• Syphilis : Wimberger's sign (bilateral
destructive lesion on medial aspect of
proximal tibial metaphysis)
48. Congenital rubella in a newborn male
demonstrates shows fraying and
longitudinal alternating radiolucent and
radiodense stripes (celery stalking)
Congenital syphilis in a 2-month old
female shows marked periosteal
reaction with destruction of the
proximal medial tibial metaphyses
(Wimberger corner sign).
In otherwise healthy adults, hematogenous osteomyelitis is very rare, osteomyelitis in adults usually follows direct implantation after surgery or trauma
N.B. :
*Differential Diagnosis for patients with a normal radiograph and focal increased radionuclide uptake in a single bone:
1-Occult fracture such as a toddler’s fracture 2-Osteod osteoma