1. How to read
musculo-skeletal x rays
Dr.Mahesh kumar MS
Dept. of Orthopedics
General Hospital
Trivandrum
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2. Rule 1
Common
things -first
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3. When you see a black
bird in trivandrum
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4. Do not say it is a penguin
Say it is a crow
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5. Appearances can be deceptive-
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do not go by appearances

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7. Reading an x ray
 It is not getting the “appearance”
 It is not commenting “oh! I have seen it
before”
 And not distracted by the “obvious”- it may
not be the causative pathology
 We should have a systematic approach
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8. ABC’s of bone Radiology
Look for
 Alignment
 Bones
 Abnormal lucency
 Abnormal sclerosis
 Periosteal reaction
 Abnormal contour
 Cartilage
 Soft Tissue
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9. Alignment
 Subluxation
 A displacement of a bone in relation to the apposing
bone at the joint, resulting in a partial loss of
continuity of the joint surfaces.
 Dislocation
 A displacement of a bone in relation to the apposing
bone at the joint, resulting in a complete loss of
continuity of the joint surfaces.
 Diastasis
 A displacement of a bone in relation to the apposing
bone in a slightly movable (e.g. sacroiliac) or
synarthrodial joint (cranial sutures).
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10. dislocation
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subluxation

12. Decreased Opacity (Lucency)
Lucency comes in several flavors. Depending on the exact
morphology and distribution of the lucency, our
differential diagnosis may vary widely.
 Lucent line
 fracture
 Focal lucency
 tumor
 infection
 Diffuse lucency
 drugs
 endocrine / metabolic
 tumor
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13. Lucent line
 A linear lucency is the classic
sign of a fracture. If a fracture
is displaced enough, it is easy
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14. Focal lucency
 With focal lucencies, bone tumors and osteomyelitis are two of the
top entities on the differential diagnosis.
 In the rest of the world, a handful of benign tumors are seen
occasionally, and the only malignant tumors commonly seen
are metastases and multiple myeloma.
 In practice, the patient’s history is often key in
distinguishing tumor and infection, as they sometimes
appear quite similar on radiographs.
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17. focal lucencies
 focal lucencies, bone tumors
and osteomyelitis are two of
the top entities on the
differential diagnosis.
 only malignant tumors
commonly seen are
metastases and multiple
myeloma
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18. Differential Diagnosis of Solitary Lucent Bone Lesions
 Fibrous Dysplasia
 Osteoblastoma
 Giant Cell Tumor
 Metastasis / Myeloma
 Aneurysmal Bone Cyst
 Chondroblastoma / Chondromyxoid Fibroma
 Hyperparathyroidism (brown tumors) / Hemangioma
 Infection
 Non-ossifying Fibroma
 Eosinophilic Granuloma / Enchondroma
 Solitary Bone Cyst
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19. Look for
 Age of the patient
 Size of the lesion
 Margins of the lesion
 Matrix- the “inside” of the lesion
 Location in the bone
 Periosteal reaction - present or not?
 multiplicity
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20. Age and lucent bone lesions
 1
 neuroblastoma
 1 - 10
 Ewing's of tubular bones
 10 - 30
 osteosarcoma, Ewing's of flat bones
 30 - 40
 reticulum cell sarcoma (Primary histiocytic lymphoma),
fibrosarcoma, parosteal osteosarcoma, malignant giant cell
tumor, lymphoma
 40 +
 metastatic carcinoma, multiple myeloma, chondrosarcoma
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21. geographic
Normal bone
Moth eaten
TYPES OF
LESIONS
permeative
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22. location
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23. Multiplicity
Differential Diagnosis of Multiple Lucent Bone Lesions
 Fibrous Dysplasia
 Metastasis / Myeloma
 Hyperparathyroidism (brown tumors) / Hemangioma
 Infection
 Eosinophilic Granuloma / Enchondroma
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24. Some tips
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25. a long lesion in a long bone,
think of
fibrous dysplasia.
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26.  Simple cyst,
 enchondroma,
 and fibrous dysplasia
can mimic each other and can be
hard to distinguish.
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27. Giant cell tumors
nearly always
occur near a joint surface.
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28. Lucent lesions of the sternum
should be considered
malignant
until proven otherwise
(Helms CA, 1983).
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29.  Certain bones in the body are
"epiphyseal equivalents".
 lucent lesions in these areas,
the classic epiphyseal entities such as chondroblastoma,
giant cell tumors and aneurysmal bone cysts.
 They are
 patella,
 calcaneus,
 most apophyses.
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30. Diffuse lucency
 Diffuse lucency usually
bespeaks some global
process capable of
affecting the entire
skeleton.
 A metabolic bone
disorder such as
osteoporosis
 multiple myeloma
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31. extensive
myelomatosis
rheumatoid arthritis
treated with steroids
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32. ?
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33. Increased Opacity (Sclerosis)
Causes of Increased Opacity
 Bone impaction or rotation
 fracture
 Bone production(reactive sclerosis)
 fracture callus
 tumor tumor bone formation or
periosteal reaction
 infection periosteal reaction
 osteoarthritis subchondral sclerosis or
osteophytosis
 Congenital
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34. Generic Differential Diagnosis of Sclerotic Bone Lesions
 Drugs
 Vascular  Vitamin D
 hemangiomas  fluoride
 infarct  Inflammatory/Idiopathic
 Infection  Congenital
 chronic osteomyelitis  bone islands
 Neoplasm  osteopoikilosis
 primary  osteopetrosis
 osteoma  pyknodysostosis
 osteosarcoma  Autoimmune
 metastatic
 prostate
 Trauma
 breast  fracture (stress)
 other  Endocrine/Metabolic
 hyperparathyroidism
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 Paget's disease

35. Bone impaction or rotation
 Although the classic
sign of a fracture is a
lucent line, some
fractures present
otherwise.
In cancellous
bones
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36. Fracture callus
 Some fractures are so
subtle that you may
miss them altogether
at first, and only
diagnose them once
they have started to
heal due to the
formation of fracture
callus.
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37. Reactive sclerosis due to tumor
 diffusely sclerotic
metastsis are seen in a
very slow process
(prostatic carcinoma)
 or a patient with diffusely
lytic mets who has been
successfully treated (with
resultant healing and
sclerosis of these
metastatic deposits).
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38. pagets
Bone island
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39. osteopoikilocytosis
melhorrostesis
osteoma
Bone island
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41. Periosteal reaction
 Depends on whether the lesion is
slow growing or rapidly growing
 Slow growing- periosteum is able to
produce bone at the same rate as tumor
grows- so solid periosteal reaction
 Rapidly growing lesion -the perisoteum
cannot cope up- hence interrupted pattern
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42. Periosteum produces bone when stimulated
Type of periosteal reaction depends on the
process than the periosteum
 Slow growing- solid periosteal reaction
 Faster growing layered or lamellar type
 Rapid, steady growth -sun burst,
codeman’s triangle
 Mixed patterns
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43. Solid Lamellar sunburst Codeman’s
triangle
Types of periosteal
reaction
Mixed type
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44. causes

Solid Periosteal Reaction
 infection
 benign neoplasms
 osteoid osteoma
 eosinophilic granuloma
 hypertrophic pulmonary osteoarthropathy
 deep venous thrombosis (lower extremity)
 Aggressive Periosteal Reaction
 osteomyelitis
 malignant neoplasms
 osteosarcoma
 chondrosarcoma
 fibrosarcoma
 lymphoma
 leukemia
 metastasis www.similima.com 44

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46. Causes of Solid Periosteal
Reaction
 Osteomyelitis
 Benign neoplasms
osteoid osteoma
 Eosinophilic granuloma
 Hypertrophic
osteoarthropathy
 Deep venous thrombosis
(lower extremity)
 Trauma (healing fracture)
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47. Causes of Aggressive (Interrupted)
Periosteal Reaction
"sunburst".  Osteomyelitis
 Malignant neoplasms
 osteosarcoma
 chondrosarcoma
 fibrosarcoma
 lymphoma
 leukemia
 metastasis
 Trauma
osteogenic sarcoma. www.similima.com 47

48. Abnormal Contour, Size and Shape
 Focal
fracture
surgery
infection
tumor
 Diffuse
dysplasia
metabolic
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49. multiple hereditary exostoses,
Paget’s disease,
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Paget’s disease,

50. Cartilage
 we can’t really see
cartilage on plain
radiographs, but we can
still use these films to
infer a few rough ideas
 decreased joint space about how the cartilage is
doing. Hyaline articular
cartilage is what
 increased joint space separates the bones in a
synovial joint. This space
taken up by the cartilage
 chondrocalcinosis is termed the "joint
space" on a plain
radiograph.
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51. Marked joint space
narrowing is noted in the
superior weight-bearing
portion of the joint space
in this patient with
osteoarthritis.
Subchondral sclerosis
and marked
osteophytosis are also
noted.
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52.  Chondrocalcinosis
(arrows) is noted in
the hyaline articular
cartilage and menisci
of this patient with
calcium
pyrophosphate
deposition (CPPD)
disease
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53. Soft Tissue
When looking at the soft tissues, one can
occasionally see a variety of useful
findings on plain films, such as:
 swelling
 gas
 calcification
 mass
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56. small to large amorphous Ca++ in the
Dystrophic damaged tissue -- may progress to
ossification (formation of cortex and medullary
space are then seen)
CPPD chondrocalcinosis; occasionally
associated with calcifications in the
soft tissues of the spine
Metastatic calcification finely speckled Ca++ throughout soft
tissues
Tumoral calcinosis big globs of Ca++, usually near a
joint
Metastatic osteosarcoma amorphous, fluffy, confluent
collection of Ca++
Primary soft tissue amorphous, fluffy, confluent
collection of Ca++
osteosarcoma www.similima.com 56

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cysticercosis

60. scleroderma
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61. dermatomyositis
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62. Heterotrophic ossification
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63. ?
SLE
Metasataic
calcifications in
soft tissues
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chondrocalcinosis

65. Tumoral
calcinosis
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66. Calcific tendinitis
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68. Thank you
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