MSK

1. METABOLIC AND
ENDOCRINE SKELETAL
DISEASE
-Dr.N.Suriyaprakash

2. COMPOSITION OF BONE
Bone
tissue
Extracellular
material
Osteoid
tissue
Inorganic
crystalline
Cellular
material
Osteoblasts
Osteoclasts
Osteocytes

3. PRODUCTION OF BONE

4. EVALUATION OF METABOLIC
AND ENDOCRINE DISORDERS
• Most metabolic and endocrine disorders are
characterized radiographically by
abnormalities in bone density
increased bone
production
increased
bone
resorption
inadequate
bone
mineraliz
ation

5. Radiologic modalities most often used to evaluate
metabolic and endocrine bone disorders are:
• Conventional radiography
• Computed tomography (CT)
• Radionuclide imaging (Scintigraphy , Bone scan)
• Magnetic resonance imaging (MRI)
• Ultrasound (US).
simplest and most widely used
method of evaluating bone
density

6. • Sec hyperPTH
• Renal
osteodysrophy
• phosphatasia
• Idiopathic
hypercalcemia
• Paget disease
• Osteopetrosis
• Pycnodysostosis
• Melorheostosis
• Hypothyroidism
• Mastocytosis
• Myelofibrosis
• Gaucher
disease
(reparative
stage)
• Fluorine
poisoning
• Intoxication
with lead,
bismuth, or
phosphorus
• Osteonecrosis
• Tuberous
sclerosis
INCREASED RADIODENSITY

7. • Osteoporosis
• Osteomalacia
• Rickets
• Scurvy
• Primary HyperPTH
• phosphatasia
• Hypophosphatmia
• Acromegaly
• Gaucher disease
• Homocystinuria
• Osteogenesis imperfecta
• Fibrogenesis imperfecta
• Cushing syndrome
• Ochronosis
• Wilson disease
(hepatolenticular
degeneration)
• Hypogonadism
INCREASED RADIOLUCENCY

8. OSTEOPOROSIS
• Osteoporosis is a
, with the actual quality of the bone remaining
normal.
• Most commonly encountered metabolic
disease of bone
• Generalized metabolic bone disease
reduction in bone quantity

9. PATHOGENESIS
–Insufficient formation of bone
–Increased resorption of bone matrix
–Decreased bone mass and
microarchitectural deterioration of bone

10. Basic distinction in osteoporosis is
between two types
 Generalized or diffuse – bone
density is decreased in the
majority of the skeleton,
especially the axial components of
the spine, pelvis, and proximal
long bones
 Regional - Loss of bone density
confined to a region or segment
of the body
 Localised - Focal losses of bone
density affecting a relatively small
area of bone

11. GENERALISED OSTEOPOROSIS
• Bone density is decreased in the majority of
the skeleton, especially the axial components
of the spine, pelvis, and proximal long bones.
• MCC - Postmenopausal status and aging.

12. CAUSES
 Senile and postmenopausal osteoporosis
 Malignant bone disease (multiple myeloma, etc.)
 Acromegaly
 Alcoholism
 Hemolytic anemia
 Hyperparathyroidism , Hyperthyroidism
 Idiopathic juvenile
 Steroids (therapy, Cushing’s) Heparin therapy

13. GENERALISED OSTEOPOROSIS

14. SENILE OSTEOPOROSIS
• Osteoporosis associated with advancing age in
male and female individuals is termed senile
osteoporosis, senescent osteoporosis, or old-
age osteoporosis.
• In the female an additional designation used is
postmenopausal osteoporosis.

15. CLINICAL FEATURES
Gradual reduction in skeletal mass
• Pain
• Spinal compression fractures and other
fractures of bone— especially the proximal
femur, ribs, humerus, and radius

16. RADIOGRAPHIC FEATURES
• Increased radiolucency
• Cortical thinning
• Altered trabecular patterns
• Fracture deformity
decreased bone mass
30–50% loss of bone
tissue must occur
before an observable
radiographic change
becomes evident.
Generalized thinning
of cortex
increase in the
marrow cavity size
As trabeculae are resorbed, those
that remain appear accentuated,
along the regions of greatest stress.
 In severe disease , the internal
trabecular architecture may be
completely lost, giving the bone a
washed-out appearance

17. Target sites
 Spine
 Pelvis and femur
 Sacrum
 Pubis
 Other sites – Sternum , Acetabulam , Neck of
femur , Tibia , Fibula ,

18. SPINE
 Curve changes - Increased thoracic kyphosis
• Decreased bone density – density of the
vertebral body, diminishes in parallel with loss
of bone mass
risk for compression fractures

19. • Trabecular changes - preferential resorption of
the horizontal trabeculae, allowing easier
delineation of vertical trabeculae- pseudo-
hemangiomatous appearance of osteoporosis
remaining

20. • Cortical Thinning - Cortical outlines of the
vertebral body and neural arch are thinned. This
is best depicted at the vertebral body endplates,
which are normally relatively thick.
• Changes in Shape - rare in the cervical spine, less
common in the upper thoracic spine, and most
common in the midthoracic and thoracolumbar
regions.

21. 1. Wedged Vertebra. Compression deformities causing
loss of the anterior vertebral body height with
preservation of the posterior height are termed
wedged vertebrae
2. Vertebra plana / Pancake vertebra - compression
deformity of the vertebral body characterized by a loss
in both the anterior and posterior vertical heights
3. Fish vertebra - Central depression of the vertebral
body endplates causes exagerrated concavity .

23. 4. Isolated endplate deformity - Central endplate
fractures are most frequent at L1 and L4.

25. Schmorl’s Nodes
• intravertebral disc herniations - protrusions
of the cartilage of the intervertebral
disc through the vertebral body endplate and
into the adjacent vertebra.
• Localized intrabody discal herniations are
frequently superimposed on the osteoporotic
spinal column.
• Most commonly occur in the thoracic and
upper lumbar spines

26. OSTEOPOROSIS: SEVERE SENILE KYPHOSIS.
Lateral Thoracic Spine. Note the severe
postural alteration, which is a complication
owing to loss of disc height and anterior
wedging of the vertebral bodies. This underlies
the physical appearance of the buffalo or
dowager’s hump deformity.

27. PELVIS AND FEMUR
• Manifestations
are identical to
most other sites
with decreased
bone density,
trabecular
changes, cortical
thinning, and
fracture-related
deformities.

28. TRABECULAR CHANGES
 Principle compressile group
 Secondary comoressile group
 Priniciple tensile group

30. SACRUM
• MCC of fracture of the sacrum is senile and
postmenopausal osteoporosis with a history
of a recent fall onto the buttocks.
• Second most common occurrence is fracture
secondary to radiotherapy of the pelvis.
• Corticosteroid therapy (rheumatoid arthritis,
chronic airways disease), alcohol abuse,
multiple myeloma, osteomalacia, osteogenesis
imperfecta, and recent hip replacement

31. • Most sensitive method of detection is isotopic
bone scan.
• Three patterns of sacral insufficiency fractures
occur based on bone scan appearance.
• H pattern (butterfly or “Honda” sign).
• I pattern
• Arc pattern.

32. • H pattern (butterfly or “Honda” sign).
Bilateral vertical fractures through the sacral
ala are connected by a transverse fracture
through the S2, S3, or S4 bodies

34. I pattern
• A single vertical fracture passes through the sacral ala.
• most common form of sacral insufficiency fracture
• Bone scan - focal linear increased tracer uptake
• Misdiagnosed as Sacroiliitis owing to the proximity of the
fracture to the adjacent sacroiliac joint
Arc pattern
A linear or curvilinear transverse fracture passes horizontally
across the sacrum

35. MRI
T1-weighted images - decreased signal
intensity
T2-weighted images - increased signal
intensity .
This is especially helpful when the fracture
line cannot be seen through the sacral ala and
is, therefore, readily overlooked.

36. PUBIS

38. REGIONALISED OSTEOPOROSIS
• Reflex Sympathetic Dystrophy Syndrome
• Disuse and Immobilization Osteoporosis
• Transient Regionalized Osteoporosis
1. Transient Osteoporosis of the Hip
2. Regional Migratory Osteoporosis

39. REFLEX SYMPATHETIC DYSTROPHY SYNDROME
• Post-traumatic osteoporosis / Sudeck’s
atrophy / Acute bone atrophy / causalgia /
complex regional pain syndrome.
• Acute onset of a painful regional osteoporosis,
usually following trivial antecedent trauma

40. RADIOGRAPHIC FEATURES
• Most characteristic radiographic change - rapidity of the
appearance and progression of the osteoporosis
INITIAL FEATURES
• Mottled appearance – Rapid resorption
• Metaphyseal osteoporosis
• Tunneled cortices
• Endosteal resorption
Joint spaces and margins are
normal, assisting in differentiating
from infection or rheumatoid
arthritis.
LATE CHANGES - entire bone density is diminished, appearing no
different from other types of osteoporosis

42. DISUSE AND IMMOBILIZATION
OSTEOPOROSIS
Traumatic injuries that
are immobilised
Motor paralysis Inflammatory lesions of
the bones and joints.
• Inhibits osteoblastic activity
• Accelerates osteoclastic mediated resorption

43. • Acetabulum - the superior cortex appears as a
double cortical line (double cortical line sign).
• Changes in the spine and pelvis are less
apparent than in the appendicular skeleton

44. Radiologic features after acute immobilization
can be recognized by four patterns of
osteoporosis
• Uniform. All bones involved exhibit a similar
degree of bone loss. most common form.
• Spotty. Localized circular lucencies predominate,
especially within the epiphyseal portions of the
bones.
• Bands. Linear transverse subchondral or
metaphyseal lucent zones.
• Cortical - Lamination or scalloping loss of
definition in the outer and inner cortical margins.

48. TRANSIENT REGIONALIZED
OSTEOPOROSIS
• Transient regionalized osteoporosis is
described as osteoporosis ocurring suddenly
which is reversible with predilection for
periarticular bone and has no associated
causal factor.
• With the advent of MRI, the disorder has also
been termed transient bone marrow edema
syndrome.

49. Transient Osteoporosis of the Hip
• Reversible stage of avascular necrosis
• Slightly more frequent in males
• Onset - sudden, with pain, antalgia, and limp
• Radiologic features
–Marked osteoporosis of the femoral head
–Less severe osteoporosis of the femoral
neck and acetabulum.
–Joint space is normal

50. MRI
MRI demonstrates bone marrow oedema
pattern involving the femoral head, neck, and
even intertrochanteric region
T1: decreased signal with loss of normal fatty
marrow signal
T2: high signal / heterogeneous signal intensity

51. Regional Migratory Osteoporosis
• Middle-aged males are most commonly
affected.
• Most frequent joints – lower extremity - knee,
ankle, foot, and hip .
• Radiologic features - localized osteoporosis of
the intraarticular components , which
subsequently regresses over 9-month period
to reappear in another joint .

52. LOCALISED OSTEOPOROSIS
• Rapidly developing osteoporosis that usually affects
the periarticular regions and has no definite etiology
like trauma or immobilization.
• It is a self-limiting and reversible disorder, of which
three subtypes have been described.

54. Periarticular osteoporosis. Anteroposterior (A) and lateral (B) radiographs of an ankle
reveal sparse trabecular pattern and increase radiolucency in the subchondral areas.

56. • Involutional
osteoporosis. Lateral
radiograph of the lumbar
spine of an 89-year-old
woman demonstrates a
relative increase in the
density of the vertebral
end plates and
resorption of the
trabeculae of spongy
bone, creating an empty
box appearance

57. RICKETS
• Rickets is a systemic disease of the infant and
young child.
• Faulty mineralization of bone matrix.

58. ETIOLOGY
 Inadequate intestinal absorption
 Vitamin D metabolism defects
 Renal tubular disorders
 Renal osteodystrophy secondary to renal
failure
 Inadequate exposure to ultraviolet radiation,
intestinal malabsorption
 Aluminum intoxication, and chronic
administration of anticonvulsants

59. CLINICAL FEATURES
• Muscle tetany
• Pain
• Irritability
• Weakness
• Delayed development
• Small stature
• Bone deformities

60. RACHITITIC
ROSARY
• Soft tissue swellings
occurring around the
growth plates owing
to hypertrophied
cartilage.
• At the anterior rib
cage, these are seen
as multiple
costochondral bumps
(rachitic rosary)

61. PATHOLOGICAL vs RADIOLOGICAL
• Decrease in the quantity of
calcified osteoid and an
increase in uncalcified
osteoid.
• Cartilage cells at the physis
grow normally but fail to
calcify and degenerate.
• Lack of osteoid mineralization
generalized
radiolucency
widening
the region
metaphyseal
zone of prov
calcification
be absent

62. RADIOGRAPHIC FEATURES
• Abnormalities will be found at the growth
plate regions of long bones.
– Generalized osteopenia
– Coarse trabecular changes
– Widened growth plates
– Frayed and cupped paintbrush metaphyses

63. RADIOGRAPHIC FEATURES
– Absent zone of provisional calcification
– Bowing deformities
– Fractures, decreased bony length, scoliosis,
and pseudofractures.

65. HEALING RICKETS
• No distinct white line of the zone of
provisional calcification is visible.
• Reappearence of this line is a useful indicator
of a good therapeutic response.
• Epiphyses also appear frayed at the borders.

67. Classic Vitamin D-Resistant rickets
• Hypophosphatemic rickets / familial vitamin D-
resistant rickets
• Mutation of PHEX gene found on the X
chromosome
• Short, stocky, and bowlegged
• Ectopic calcifications and ossifications in the axial
and the appendicular skeleton

69. SCURVY
 A/K/A barlow’s disease / hypovitaminosis C
 Long-term deficiency of vitamin C
 Infants between the ages of 4 and 18 months
are primarily affected.

70. CLINICAL FEATURES
• Clinical hallmark - Tendency toward spontaneous
hemorrhage owing to capillary fragility.
• Cutaneous petechiae, bleeding gums, melena,
and hematuria
• Joint swelling, irritability, pain, and a tendency to
lie supine and motionless with the thighs
abducted (frog-leg position)

71. PATHOLOGIC FEATURES
Vitamin C
collagen osteoid endothelial linings
formation of intercellular substances
generalized
osteopenia
Bleeding
manifestations

72. RADIOGRAPHIC FEATURES
• Osteopenia - generalized decrease in bone
density with thinning of the cortex and loss of
trabecular definition
• White line of frankel - Dense zone of provisional
calcification. Enhancement of the dense
metaphyseal zone of calcified cartilage occurs
owing to delayed conversion into bone

73. • Wimberger’s sign - Ring epiphysis. The
peripheral margin of the epiphysis appears
dense, whereas the central portion is more
radiolucent.
• Corner (angle) sign. Irregularity of the
metaphyseal margins frequently occurs
secondary to infractions of the epiphyseal–
metaphyseal junction.

74. • Pelken’s spurs. These bony protuberances
occur at the metaphyseal margins and extend
at right angles away from the shaft axis.
• Scorbutic zone (Trümmerfeld’s zone). Directly
beneath thezone of provisional calcification a
radiolucent band may be visible, representing
disordered osteoid formation.

75. • Subperiosteal hemorrhage. Extensions of
extravasated blood frequently lift the
periosteum away from the bone and will later
calcify, especially during healing

78. OSTEOMALACIA
• Osteomalacia is a metabolic disorder that
alters the quality of bone
• Occurs only after bone growth has ceased
• MC clinical presentation - bone pain and
muscle weakness

79. CAUSES OF OSTEOMAACIA
Cause
– faulty absorption of fat-
soluble vitamin D from
the gastrointestinal
tract secondary to
malabsorption
syndrome.
– dysfunction of the
proximal renal tubules -
Renal osteomalacia

80. RADIOGRAPHIC FEATURES
No definitive radiologic diagnosis can be made
without the appropriate clinical and
laboratory support, owing to the non-specific
nature of the skeletal changes

81. • Decreased Bone Density
• Coarsened Trabecular Pattern
• Loss of Cortical Definition
Bones will appear more radiolucent
due to diminished bone mineral
content
Decrease in the overall number of bony trabeculae within
all bones enhances the contrast of those remaining
Texture of the spongiosa may appear coarse and mottled.
Cortex reveals it to be thinner and
altered in structure

82. Pseudo-Fractures
• Pseudo-fractures are linear radiolucencies that
usually occur bilaterally and symmetrically in
predictable locations.
• MC sites - femoral necks, pubic and ischial
rami, ribs, and axillary margins of the
scapulae.

83. Deformities
• Majority of the deformities occur in the weight-bearing
bones.
• In the pelvis, inferior displacement of the sacrum produces a
triradiate shape to the pelvic canal. Medial acetabular
migration forms a protrusio acetabuli deformity.
• Bowing of the femur and tibia also are seen.
• In the spine, kyphoscoliosis and increased endplate concavity
predominate. Bellshaped thoracic cage has also been
described.

84. MILKMAN SYNDROME
• Mild form of osteomalacia
• Numerous pseudofractures

85. ONCOGENIC OSTEOMALACIA
• a/k/a tumor-induced
osteomalacia
• paraneoplastic
syndrome
Features
• Hypophosphatemia
• Hyperphosphaturia
• Low levels of plasma
1,25-dihydroxyvitamin D
Benign, slow-growing vascular lesions
Osteoblastoma-like lesions
Nonossifying fibroma-like lesions
Secrete excessive amounts of
Phosphatonin
impairs phosphate reabsorption,
Hypophosphatemia
low levels of 1,25 - 2(OH)D

87. METABOLIC AND
ENDOCRINE SKELETAL
DISEASE - II
-Dr.N.Suriyaprakash
JR , Dept of RD , GKMCH

88. HYPERPARATHYROIDISM
• A/K/A generalized osteitis fibrosa cystica or
Recklinghausen disease of bone
• Hyperparathyroidism is the general term applied to
overactivity of the parathyroid gland.
THREE BASIC FORMS OF HYPERPARATHYROIDISM
Primary hyperparathyroidism-
Most common cause of hypercalcemia
Due to a parathyroid adenoma , carcinoma,
hyperplasia, or ectopic tumors, producing a
parathormone type of substance.

89.  elevated levels of parathormone, hypercalcemia, and
hypophosphatemia.
Secondary hyperparathyroidism
Most common complications of chronic renal
disease, allowing for persistent loss of calcium and
phosphorous and thus stimulating parathormone
release.
Tertiary hyperparathyroidism
In dialysis patients, the parathyroid gland may act
independently of serum calcium levels.

90. Parathyroid hyperplasia
Parathyroid adenoma
parathyroid carcinoma
Excessive secretion of
parathormone
Hypercalcemia
Hyperphosphaturia
Hypophosphatemia

91. CLINICAL PROFILE
 30 to 50 years old female
 Weakness, lethargy, polydipsia, and polyuria
 Hypercalcemia - muscles will be hypotonic and
formation of renal calculi
 Elevated Parathormone concentration

92. RADIOGRAPHIC FEATURES
• Radiologic differentiation between primary and
secondary hyperparathyroidism is usually not
possible
•Subperiosteal
resorption
•Decreased bone
density
•Accentuated
trabecular pattern
•Loss of cortical
definition
•Subligamnetous bone
resorption
•Brown tumors
Bones Joints Soft tissues
Dialysis-related
arthropathy (DRA)
Dialysis-related
spondyloarthropathy
(DRSA)
Urinary Tract
Articulations
Miscellaneous Tissues
- Periarticular
structures, such as
blood vessels,
ligaments, tendons,
muscle, and
subcutaneous tissues

93. TARGET SITES
Hands
• Demonstration of subperiosteal resorption is the
hallmark of hyperparathyroidism.
• MC Location - proximal and middle phalanges of
second and third digits along radial margins
• outer cortex will appear frayed and irregular

95. Skull
• Diffuse granular deossification produces a mottled
appearance to the calvaria (salt and pepper or
pepper pot skull

96. Spine and Pelvis
• All vertebral segments show generalized
deossification and trabecular accentuation.
• Endplate concavities due to bone softening
• Uniform condensation in the sub-endplate zones of
the bodies (rugger-jersey spine).

99. • Subchondral resorption at the sacroiliac and pubic
articulations produces marked apparent widening of
these joints and can be readily confused with erosive
spondyloarthropathies, such as ankylosing spondylitis.
• Discovertebral destructive lesions (e.g., DRSA) are most
common in the cervical spine and appear identical to
infection

100. Shoulder
 Resorption of the distal clavicle subchondral bone
bilaterally is an early and reliable indicator of
hyperparathyroidism.
 Articular surface is indistinct and frayed.
 Infection and post-traumatic osteolysis

102. ACROMEGALY
• In adulthood, excessive growth hormone secretion
from a pituitary eosinophilic adenoma produces
growth of intramembranous bone tissue and
subcutaneous hypertrophy
• Prominent in the hands and feet

103. CLINICAL FEATURES
• Physical features - malocclusion, prominent
forehead; thickened tongue; and broad, large hands.
• Bitemporal hemianopia, headache, and carpal tunnel
syndrome are common.
• Acromegalic patients are predisposed to
degenerative arthritis, especially of the spine and
weight-bearing joints.

104. RADIOGRAPHIC FEATURES
Skin changes
• usual site for skin changes actually measured
is the heel pad thickness.
• heel pad thickness > 20 mm is suggestive of
acromegaly

105. SKULL CHANGES
• Sella turcica enlargement from the pituitary
neoplasm
• Sinus overgrowth
• Occipital protuberance overgrowth
• Malocclusion
• Widened mandibular angle (pragnathic jaw)

107. Hand
• Widened shafts of the phalanges and metacarpals
• Bony protuberances
• Prominent ungual tufts - spade-like appearance
• A reliable indicator - generalized increase in joint
space width owing to cartilage overgrowth.

108. Figure 14-39 ACROMEGALY. A. PA Hand. Note
the characteristic features of widened joint
spaces and periosteal neW bone formation. B.
Close-Up, Distal Tufts. Note that the distal
tufts are classically enlarged, showing the
spade-like deformity (arrows).

109. ACROMEGALY. AP Hip. Note the
widened axial joint cavity, reflecting
the overgrowth of intra-articular
cartilage (arrowheads). Despite this
joint widening weight-bearing
superior compartment is narrowed,
with evidence of a degenerative
lateral acetabular osteophyte
(arrow). A subchondral cyst can be
seen in the femoral head.
COMMENT: The appearance of
degenerative joint changes is
common in acromegaly

110. SPINE
• Vertebral dimensions increase in both sagittal
and transverse planes, especially in the
lumbar spine.
– vertical height – unchanged vertebral
bodies appearing flattened and increased in
their sagittal dimensions platyspondyly.
• Premature degeneration with exuberant
osteophytes and widened disc heights
complete the most typically observed
changes.
• posterior body scalloping may be observed
from dural ectasia.

111. • The atlantodental interspace may be increased up to
6 mm owing to cartilage overgrowth, not transverse
ligament instability.
• Widening of the facet joints
• Hyperostosis of the tips of the spinous processes
• Spinal stenosis - thickened laminae and articular
process with the spinal ligaments thickened and
calcified.

112. HYPERVITAMINOSIS A
• Hypervitaminosis A can occur both in adults and in
children.
• C/F - Dermatitis, Pruritus, Alopecia, and Yellowing of
the skin. Hepatosplenomegaly can be present.

113. RADIOLOGICAL FEATURE
• Solid, periosteal new bone along the shafts of
the long bones - femurs, tibia, fibula,
metatarsals, humerus, ulna, radius, and
metacarpals.
• Diastasis of the cranial sutures, most marked
at bregma, is also common.
• Increased radioisotope uptake on bone scan
• Diffuse osteopenia

114. HYPERVITAMINOSIS D
• C/F - nausea, anorexia, polyuria, and
polydipsia.
• Hypercalcemia
• The most characteristic radiologic feature is
the extensive calcification in blood vessel
walls, kidneys, and periarticular tissues

115. LANGERHANS CELL
HISTIOCYTOSIS
• Histiocytosis X is a disease of unknown origin that
encompasses a wide spectrum of clinical, pathologic, and
radiologic features
• Hallmark - abnormal proliferation of reticuloendothelial cells
• Three entities are encompassed under this term:
• Letterer-siwe disease
• Hand-schüller-christian disease
• Eosinophilic granuloma

116. LETTERER SIWE DISEASE
• Acute, fulminating, fatal disease affecting children <
3 years of age.
• C/F – Critically ill with a high fever, skin rash, bleeding
gums, malaise, lymphadenopathy,
hepatosplenomegaly, and respiratory symptoms.

117. • Skeletal lesions are infrequent owing to the
rapidity of its progression.
• MC bone change - lytic lesionsin the calvaria.
• Long bone lesions - aggressive, with irregular
rarefaction of the diaphysis and surrounding
laminated periosteal response closely
simulating Ewing’s sarcoma.

118. HAND-SCHULLER-CHRISTIAN DISEASE
• Typically isolated to the cranial bones, the
eyes, and the pituitary gland

119. RADIOLOGICAL FEATURES
• radiologic hallmark - polyostotic destructive
foci in an immature skeleton particularly in
the skull, pelvis, and long bones
• Long bones- multiple lytic defects affecting
the entire bone from the diaphysis to the
metaphysis coalesing to create larger defects
marked by endosteal scalloping and beveling
of the cortex - hole-within-hole appearance

120. • In the skull, confluence of these individual
lesions generates large map-like regions of
radiolucency (geographic skull ) with a
peripheral beveled edge and a hole-within-
hole appearance

121. EOSINOPHILIC GRANULOMA
• Least severe but most common of all histiocytoses.
• Typically lacks the systemic features of hand-schüller-
christian or letterer-siwe disease
• Vertebral involvement – pain
• Temporal bone involvement – om like symptoms

122. • Monostotic presentations are three times
more common than polyostotic presentations
• Pain may be the primary symptom (6), and the
diagnosis often requires histopathologic
analysis of the lesions

123. RADIOGRAPHIC FEATURES
• Most lesions are visible on plain films.
• CT and MRI are useful in defining a soft tissue mass,
periosteal response, and characteristics of the lesion.
• Once a lesion is isolated, a bone scan may well
identify additional lesions.
 Solitary and geographic
 Round to oval in shape
 Sharply demarcated borders
 Prominent endosteal scallopingwith solid or
laminated periosteal response

124. SKULL
• Sharply demarcated round to oval osteolytic lesion of
1–4 cm is characteristic
• Beveled edge sign / Hole within hole - Involve one
table greater than the other to produce a double
contour
• Button sequestrum - within the lesion a central focus
of bone may remain isolated, identified on CT
examination.
• The lesion does not respect suture lines and readily
infiltrates into adjacent parts of the calvaria.

125. MANDIBLE
• Pain is the primary symptom
• Radiographically, the lesion is osteolytic,
expansile, and does not involve the teeth
except to leave them displaced and isolated
floating teeth sign.
• Early lesions typically begin near last molar
and enlarge predominantly forward without
destroying the lower mandibular border.

126. Spine
• Involve the thoracic spine , lumbar spine; and < 15%,
the cervical spine.
• Vertebral body is usually involved with relative
sparing of the neural arch structures.
• Ghostly appearance – When Neural arch is involved
destruction of internal matrix with preserved the
cortical outline is noted.

127. • Vertebra plana, Silver dollar vertebra, Coin-on-edge
vertebra - most prominent feature in the lumbar and
thoracic spine is pathologic fracture, with dramatic
loss of vertebral height involving both the anterior
and posterior vertebral body surfaces.

131. THYROID DISORDERS
Three thyroid-related disorders may exhibit skeletal
changes:
• Hyperthyroidism
• Hypothyroidism
• Thyroid acropachy

132. CRETINISM
• Congenital hypothyroidism
• Exerts considerable growth and developmental-inhibiting
factor to the skeleton.
• Cretinoid epiphyses delayed closure and fragmented
epiphyses
• Occasional wormian bones
• Wedged thoracolumbar sail vertebra.
• Bilateral slipped capital femoral epiphysis (rare)

133. Juvenile hypothyroidism. (A) Dorsovolar radiograph of the right hand of a 13-year-
old boy demonstrates skeletal immaturity; the bone age is approximately 8 years.
Note the “fragmented” secondary ossification centers of the distal ulna and distal
phalanges. In fact, they represent separated foci of ossification.
(B) The hand of a healthy boy of the same age is shown for comparison

134. Congenital hypothyroidism (cretinism). Anteroposterior radiograph of the pelvis of a 5-year-old
boy shows pseudofragmentation of both capital femoral epiphyses. This process may be
mistaken for Legg- Calvé-Perthes disease

135. THYROID ACROPACHY
• Thyroid acropachy is an unusual complication to a
treated hyperthyroid patient who is now maintaining
normal thyroid activity.
• C/F - digital swelling that is painless and progressive.
• Radiological feature - thick and dense periostitis
arising from the radial aspect of the small hand
bones. Similar changes exhibited on the tibial aspects
of the foot bones

136. Figure 14-41 THYROID ACROPACHY. A. PA Hands. Observe the thick, dense periosteal new bone a
the metacarpals and phalanges (arrows). B. PA Feet. Note that similar changes are
seen on the medial surface of the first metatarsal (arrows), a distinctively characteristic site for
thyroid acropachy of the foot

137. PAGETS DISEASE
• Chronic, progressive disturbance in bone metabolism
that primarily affects older persons.
• More common in men than in women
• Skeletal abnormalities seen in paget disease are
frequently asymptomatic.
• Frequency of bone involvement - pelvis, femur, skull,
tibia, vertebrae, clavicle, humerus, and ribs

138. HALLMARK
Disordered and extremely active bone
remodeling, secondary to both osteoclastic
bone resorption and osteoblastic bone
formation in a characteristic mosaic pattern.

139. • increase in osteoblastic activity - elevated
levels of serum alkaline phosphatase
• the increase in osteoclastic bone resorption -
high urinary levels of hydroxyproline,

140. IMAGING EVALUATION
EARLY PHASE- THE OSTEOLYTIC OR HOT PHASE
 Active bone resorption is evident as a
radiolucent wedge or an elongated area with
sharp borders that destroys both the cortex and
cancellous bone as it advances along the shaft.
 This phenomenon are advancing wedge, candle
flame, and blade of grass.

141. Osteolytic phase of Paget disease. (A)
Anteroposterior radiograph of the
lower leg of a 68-year-old
woman shows an advancing wedge of
osteolytic destruction in the midportion
of the tibia (arrow). (B) Magnification
study of the midfemur in another
patient shows the purely osteolytic
phase of Paget disease. In
both examples, the lesion resembles a
blade of grass or a candle flame

142. (A) Lateral radiograph of the skull shows an osteolytic lesion in the parietooccipital area. This
sharply demarcated defect, known as osteoporosis circumscripta, represents a hot
phase of the disease. (B) Radionuclide bone scan shows a characteristic localized increased
uptake of the radiopharmaceutical tracer resulting in the appearance of a “yarmulke” sign. (C)
Lateral radiograph of the skull reveals osteoporosis circumscripta in the frontoparietal area.

143. INTERMEDIATE OR MIXED PHASE
• Bone destruction is accompanied by new bone
formation, with the latter process tending to
predominate.
• Bone remodeling appears radiographically as
thickening of the cortex and coarse
trabeculation of cancellous bone

144. • Intermediate phase of
Paget disease. (A) In the
intermediate phase
thickening of the cortex
and a coarse trabecular
pattern in the medullary
portion of the bone are
characteristic features.
Note the anterior
bowing. (B) intermediate
phase is seen in the
pubic and ischial bones.
(C) Mixed phase
affecting the proximal
phalanx of the middle
finger with monostotic
form of the disease

145. • Spine - the thin cortex of the vertebral body,
which disappears in the hot phase, is later
replaced by broad, coarsely trabeculated
bone, forming what appears to be a “picture
frame” around the body .
• Skull - focal patchy densities with a “cotton
ball” appearance are characteristic

146. Intermediate phase of Paget disease.
(A) Involvement of the lumbar spine in
the mixed phase can be recognized by
the “picture frame” appearance of the
vertebral bodies (arrows) created by
dense sclerotic bone on the periphery
and greater radiolucency in the center.
Note the partial replacement of
vertebral end plates by coarsely
trabeculated bone. (B) In another
patient, the picture frame appearance
of the vertebral body of L2 marks the
intermediate phase of Paget disease.
(C) Sagittal STIR MRI of the lumbar
spine in another patient with Paget
disease affecting the L5 vertebral body
shows the MRI-equivalent of picture
frame.

147. Intermediate phase of Paget
disease. Focal patchy densities
in the skull, having a “cotton
ball” appearance, are typical
of the intermediate phase of
Paget disease

148. COOL OR SCLEROTIC PHASE
• a diffuse increase of bone density occurs
together with enlargement and widening of
the bone and marked cortical thickening, with
blurring of the demarcation between cortex
and spongiosa.
• Bowing of long bones may become a striking
feature
• Similar changes are observed in the skull,
where obliteration of the diploic space is also
a typical feature

149. Cool phase of Paget disease. In the cool phase, there is thickening of the cortex and bone
deformity. (A) The pelvic cavity assume a triangular appearance. (B) Involvement of a long bone,
in this case the distal humerus of a 60-year-old woman, exhibits marked cortical thickening,
narrowing of the medullary cavity, and a coarse trabecular pattern.

150. (C) Similar changes are present in the (D)
Anteroposterior radiograph of the skull of an
reveals typical changes of the cool phase of
Paget disease.

151. Cool phase of Paget disease. Anteroposterior
radiograph of the forearm with
polyostotic Paget disease shows enlargement
of the left radius with a marked bowing
deformity. the cool phase of the disease are
seen in the diffuse sclerotic changes and the
indistinct demarcation between
the cortex and the spongiosa

152. Anteroposterior and lateral radiographs of the right leg show thickening of the
cortex and a coarse trabeculation of the proximal tibia. (B) Sagittal and coronal
reformatted CT images demonstrate these abnormalities to the better advantage
lack of distinction between the cortex and the spongiosa (arrows). (C) 3D CT
reconstructed image shows deformity of the tibia
and anterior bowing

153. Magnetic resonance imaging (MRI)
• demonstrate cortical and intramedullary
involvement better
• exclude (or confirm) extension of the process into
the soft tissues.
In general, the pagetic bone exhibits heterogeneous
signal intensity.
• T1-weighted sequences - intermediate-to low SI
• T2 weighting - high, intermediate, or low SI
depending on the stage of the disease and degree
of fibrosis and sclerosis

154. MRI of Paget disease. (A) Anteroposterior radiograph of the left distal femur shows
typical appearance of Paget disease: enlargement of the bone, cortical thickening,
and sclerosis and coarse trabecular pattern of cancellous bone. (B,C) Two coronal T1-
weighted MR images demonstrate cortical thickening (arrow) and low-signal coarse
cancellous trabeculae

155. (D) Coronal T2-weighted MRI
shows heterogeneous signal
in the femoral condyles. (E,F)
Sagittal T1-weighted and
axial T2-weighted MRI of the
knee in another patient
demonstrate the
characteristic coarse
trabecular pattern and
cortical thickening of the
distal femur. Note the
prominent areas of fatty
marrow between the
thickened trabeculae

156. Scintigraphy
• increased uptake of bone-
seeking radiotracer in all
three phases of the
disease, but particularly
in the hot and
intermediate, due to
increased vascularity and
osteoblastic activity in
abnormal bone.

157. DIFFERENTIAL DIAGNOSIS
• familial
idiopathic
hyperphosphat
asia, also called
juvenile Paget
disease -
articular ends
of the bone
may not be
affected.
(A) AP radiograph of the shoulder and arm reveals marked thickening of the cortex of the
humerus and coarsening of the bony trabeculae, resembling pagetic bone. (B) Radiograph of
the hands shows sclerotic changes in the bones and a marked narrowing of the medullary
cavity of the metacarpals and phalanges

158. • Van buchem disease (hyperostosis corticalis
generalisata)
• Vertebral hemangioma
• Rugger-jersey spine seen in secondary
hyperparathyroidism
• Lymphoma
• Extensive osteoblastic metastases

159. COMPLICATIONS
Secondary osteoarthritisPathological fracture

160. Pagets sarcoma
The most serious complication of Paget disease
is sarcomatous degeneration.
Radiographically, it can be recognized by:
• osteolytic bone destruction at the site of the
pagetic lesion
• cortical breakthrough
• soft-tissue mass

161. (A) Radiograph of the pelvis shows extensive involvement of the left ilium, pubis, and ischium by
Paget disease. There is also destruction of the cortex and a large soft-tissue mass accompanied
by bone formation (arrow), typical findings for osteosarcoma. (B) CT scan demonstrates the
softtissue mass more clearly (open arrows).

162. (A) Coronal T1-weighted image
shows Paget disease affecting
the distal femur. Destruction of
the cortex and soft-tissue mass
are well demonstrated.
(B) Coronal STIR and (C) axial T2-
weighted sequences confirm
the presence of a soft-tissue
mass (arrows), thus
corroborating the diagnosis of
malignant transformation

163. Metastasis in Pagets disease
Anteroposterior radiograph of the pelvis shows extensive osteolytic destruction of
the right ilium, ischium, and pubis secondary to metastatic renal cell carcinoma
(hypernephroma). Note the typical involvement of the pelvis by Paget disease. This
metastatic lesion should not be mistaken for Paget sarcoma