2. Bone dysplasias are genetic disorders of the
skeleton.
More than 300 different bone dysplasias are
currently known.
3. Bone dysplasias can
cause dwarfism,
brittle bones,
leg and spine
deformities
and many other
complications.
4. We study bone dysplasias
to improve diagnosis
and management of these rare disorders.
In addition, bone dysplasias give the rare opportunity
to study the impact of single genes on human bone
and cartilage development.
5. The diagnosis of these lesions is mainly
radiological and often entirely so.
6. Accurate diagnosis
is of prime importance
Genetic councelling is ,of course
Well established speciality depending on accurate
diagnosis
9. also been named ToulouseLautrec syndrome,
after the French artist
Henri de Toulouse-Lautrec,
who suffered from the
disease.
10. rare clinical entity,
an autosomal recessive osteochondrodysplasia,
usually diagnosed at an early age
11. With INCIDENCE estimated to be 1.7 per 1 million
births.
Life expectancy for a Pycnodysostosis patient is
normal.
12. a lysosomal storage disease of the bone
caused by a mutation in the gene that codes
the enzyme cathepsin K.
13. cathepsin K.
Is important for osteoclasts,
to reabsorb the bone and build new bone
14. The normal functioning of osteoclasts in
individuals with pycnodysostosis is disrupted by a
lack of cathepsin K,
unable to adequately reabsorb the
organic matrix.
This process, also called remodelling, is vital for
normal bone maintenance.
15. The bones in individuals afflicted with
pycnodysostosis are abnormally dense
and brittle as a result of this insufficient reabsorption process.
17. short STATURE,
fractures,
large head with frontal and parietal bossing,
Obtuse MANDIBULAR ANGLE,
The typical 'open mouth outline ' facial
appearance is due to frontal
bossing, micrognatia, loss of the mandibular angle
18. prominent eyes with bluish sclerae,
underdeveloped facial bones,
Deficient growth of the maxilla and mandible
makes normal tooth alignment impossible, with
dental crowding, DENTAL ANOMALIES,
persistence of deciduous teeth resulting
a double row of teeth.
19. short, broad HANDS and feet with dystrophic nails
and
acro-osteolysis of the terminal PHALANGES
TRUNK DEFORMITIES such as
kyphosis,
scoliosis,
increased lumbar lordosis.
24.
THE SKULL shows
open anterior fontanelle and sutures
small facial bones,hypoplastic maxilla.
non-pneumatised paranasal sinuses
flattened /obtuse mandibular angle .
sclerosis being more pronounced in the periorbital
region (“harlequin appearance” or “raccoon mask”
sign),also calvarium and the base .
26. PA skull radiography
generalized sclerosis
more pronounced in the
periorbital region
(“harlequin appearance” or
“raccoon mask” sign),
open fontanelles and
cranial sutures, absence of
facial sinuses.
30. IN THE HAND ;
terminal phalanges are partially or totally aplastic
with loss of ungual tufts.
THORAX
The acromial ends of the clavicles may be aplastic.
31. Hand radiograph, age 3 years.
acro-osteolysis in the
distal phalanx of
thumb and index
fingers (arrows)
and generalised
increased bone
density.
33. LIMBS
Cortices—dense,
medullary canals are not completely oblitreated.
coxa valga and abnormal radioulnar articulation.
SPINE
failure of complete segmentation of the atlas, axis, and
the lower lumbar spine,
36. PYKNODYSOSTOSIS
typical facial features,, open fontenella,, high arched furrowed palate and
radiological features including open cranial sutures, obtuse angle of mandible,
generalized skeletal sclerosis.
37. DDx
Various bone diseases should be considered in the
differential diagnosis of pyknodysostosis, particularly
cleidocranial dysostosis,
acroosteolysis,
osteogenesis imperfecta, and
osteopetrosis.
38. pycnodysostosi cleidocranial
s.
dysostosis
osteogenesis
imperfecta
osteopetrosis
Small facial
Mandible is
bones,Mandib normal in size
el has no
angle.hypoplas
tic maxilla
history of
frequent
fractures
normal
stature, cranial
nerve
compression,
Clavicle rarely
affected
clavicle is also
involved,
associated
features
choanal atresia
, blue sclera.
Skull dysplasia
and hipoplasia
of the distal
phalanges ,not
common
autosomally
recessive
autosomal
dominant
inheritance
41. Rare hereditary disorder
Defective osteoclast function with failure of
proper reabsorption produces sclerotic bone
Structurally weak
42. TYPES(osteopetrosois)
(1)
AUTOSOMAL RECESSIVE TYPE
i)
Severe form (ARO):
Also known as malignant osteopetrosis,
usually results in stillbirth/early death.
who survive present in early childhood with fractures,
diffuse marrow space obliteration leading to
pancytopaenia.
ii) Intermediate severity form (IRO):
(Infantile) with cerebral calcifications ("marble brain
syndrome").
43. Osteopetrosis in a
neonate.
Lateral skull
radiograph shows
sclerosis,
most pronounced in
the skull base
with relative sparing
of the mandible. The
cervical vertebrae are
also sclerotic.
44. Neonate with typical features of autosomal recessive type of osteopetrosis.
widened costo-chondral junctions; typical metaphyseal lucent bands and
lost bony cortico-medullary differentiation.
46. (2) BENIGN ADULT AUTOSOMAL DOMINANT TYPE
i)
type I
sclerosis of the skul vault
ii) type 2
sclerosis of the skull base and pelvis
a typical "bone-within-bone" appearance of the vertebral
bodies due to endplate sclerosis,,,RUGGER JERSEY SPINE.
("sandwich" spine").
(3) X-linked:
Rare.
47. Benign adult autosomal dominant type
50% asymptomatic
Recurrent fractures
Mild anemia
Prognosis: normal
48. Benign adult autosomal dominant type
X-ray findings
Diffuse osteosclerosis
Cortical thickening with medullary encroachment
Erlenmeyer flask deformity
= clublike long bones due to lack of tubulization +
flaring of ends
49. Bone-within-bone appearance
(differentiates from other sclerosing
dysplasias) maybe
vertical-----in long bones,,shafts and
digits
transverse-------at metaphysis
Arcuate------beneath the iliac crest
51. a young woman with autosomal dominant osteopetrosis.----sclerosis
and widening of the diploic space . The spine images show the classic
sandwich vertebrae sign (the rugger jersey spine). The femur demonstrates
increased sclerosis and an Erlenmeyer flask deformity.
52. One of the classical appearances of autosomal
dominant osteopetrosis is
the "bone within a bone" appearance .
59. classic sandwich vertebrae of osteopetrosis (red arrows)
thickening and sclerosis of the vertebral endplates, and of the
bone adjacent to the endplates.
60. The tubular bones
may have an
Erlenmeyer flask type deformity.
61. An Erlenmeyer flask deformity
refers to a radiographic appearance typically on a
femoral radiograph
where there is
relative constriction of the diaphysis
and flaring of the metaphysis.
69. OSTEOPETROSIS
Complications:
Fractures (common because of brittle bones) with
abundant callus + normal healing
Crowding of marrow ( anemia + extramedullary
hematopoiesis)
Frequently terminates in acute leukemia
Rx: bone marrow transplant
70. DDx:
Heavy metal poisoning
Melorheostosis (limited to one extremity)
Hypervitaminosis D
Pyknodysostosis
Fibrous dysplasia of skull / face
72. also known as Leri disease
is a rare sclerosing bone dysplasia.
73. The name is derived from the Greek words for
melos (limb),
rhein (flow)and
ostos (bone),
due to its characteristic appearance of flowing
hyperostosis.
75. General Considerations
Cause is unknown
Produces thickening of the endosteum and
periosteum
Peak age of presentation is 5-20 years
76. May be monostotic or polyostotic
May
involve one entire limb
Usually does
not involve multiple limbs
Twice as common in lower extremities than
elsewhere
77. Clinical Findings
About 50% affected develop symptoms by age 20
Adults present with
Pain
Joint stiffness
Deformity that may progress over time
Children may present with
Leg length discrepancies
Joint contractures
78.
79. • predominantly affects the appendicular skeleton
• is most common in the long bones of the upper and
lower extremities,
• can be seen in the hands and feet as well
• It may affect
a single bone (monostotic),
a single limb (monomelic),
or multiple bones (polyostotic).
80. Photographs showing the swelling in the ring finger.
A 16 year old female--- a 4 year history of progressively increasing
swelling and intermittent dull ache in the ring finger of the right hand.
no similar swelling in any other part of her body.
no history of paraesthesia or restriction of movement. There were no
similar complaints in the family
81. A.P. and lateral Radiographs showing
candle wax appearance in the
proximal phalanx of ring finger
Computed tomography of
hand
cortical hyperostosis with
thickening resembling
candle wax.
82. Radiographic features
Plain film
Five patterns have been described 1.
Classic(Candle-wax appearance)
osteoma - like
myositis ossificans - like
osteopathia striata - like
mixed
83. The dripping (or flowing) candle wax sign
is seen on conventional
radiographs depicting
bone. The appearance is
that of irregular
cortical hyperostosis,
typically occurring on
one side of the involved
bone, and has been
likened to melted wax
flowing down one side
of a candle.
85. The dripping candle wax sign
developmental error ---in intramembranous bone
formation.
leads to an irregular thickening of cortical bone
(cortical hyperostosis) that extends up to (but
usually not past) the articular surface.
86. Pathologically—
both overproduction of bone matrix
and increased angiogenesis.
The DISTRIBUTION OF AFFECTED BONE is
thought to be due to the predilection of
melorheostosis to occur in sclerotomes (skeletal
regions innervated by a single spinal sensory
nerve).
89. Classical appearances of
melorheostosis
involving the right fibula and
lateral side of the foot.
AP radiograph ;
dense cortical and extra-cortical
bone formation (white arrows)
along the length of the distal fibula
to the lateral malleolus
with associated hyperostosis in the
lateral hind foot bones (black
arrows).
90. Frontal radiographs
of the hand ;
undulating cortical
hyperostosis
representing the
classical "candlewax" dripping
appearance
involving only the
radial side of the 3rd
metacarpal shaft.
92. Cortical lesions are
progressive and may
result in narrowing
of the medullary
canal and stenosis
of an adjacent
lumen, foramen, or
of the spinal canal.
Radiographically, the lesions show undulating
cortical hyperostosis which has been likened
to flowing candle wax.
98. CT scan will show clear demarcation between normal
and abnormal bone . CT scan is helpful to confirm or
exclude continuity of osseous and soft tissue
abnormalities [7].
99. Noncontiguous transverse CT images through eighth (left) and ninth (right) right
posterior ribs of patient in Figure 1 show sharp delineation between normal and
affected bone segments (arrows), highlighting sclerotomal distribution.
103. Myositis ossificanslike pattern.
A P radiograph of the
right elbow
shows
dense, lobular, soft-tissue
mineralisation (arrows)
adjacent to the radial
head.
105. Osteopathia striata-like
pattern.
AP radiograph right knee
demonstrates
longitudinal, dense bandlike areas of increased
intramedullary density
(arrows). Note also the softtissue mineralization.
106. MR imaging shows heterogeneous signal intensity due
to mixture of osseous, fibrous, adipose and
cartilaginous tissue which these lesions contain
107. (a) MRI appearances. Sagittal, T2*-weighted, gradient echo image of the knee
showing multiple areas of intramedullary signal void (arrows). Note the
absence of patella as patellectomy was performed for severe pain. (b) Plain
radiograph in the same patient showing the area of sclerosis seen as the signal
void lesions on the MRI.
108. Patients with meloreostosis may have associated
cutaneous and soft tissue lesions such as
vascular malformations,
neurofibromatosis,
hemangioma,
arterial aneurysms,
linear scleroderma,
tuberous sclerosis,
hemangiomas, and
focal subcutaneous fibrosis.
109. Not infrequently
features of melorheostosis, osteopathia
striata and osteopoikilosis may co-exist in so-called
OVERLAP SYNDROMES.
These conditions may share an underlying aetiology 1.
110. Differential Diagnosis
Osteopathia striata
Longitudinal dense striations
Osteopoikilosis
Punctate, rounded bone islands surrounding
joints,symmetrical involvement,
absence of soft tissue involvement, negative scintigraphy,
no clinical complaints and autosomal dominancy
Osteosarcoma
Bone destruction
111. Nuclear medicine
Increase in radiotracer uptake is usually present on
late phase bone scans 2.
116. In conclusion,
radiographs are diagnostic for melorheostotic lesions.
MR imaging is useful to detect the presence and extent
of associated mineralized and nonmineralised soft
tissue masses and may obviate unwarranted biopsy
and a radical procedure.
118. Osteopoikilosis is a benign, asymptomatic sclerosing
dysplasis.Affects both M and F.
May be seen at any age.
Cutaneous lesions in 25%.
Etiology unknown.
Inherited and spontaneous cases occur.
119. RADIOGRAPHICALLY,
Sclerotic circular or ovoid lesions symmetrically
distributed in a periarticular location.
Lesions can increase or decrease in size and number in
serial radiographs or even disappear.
Lesions do not have increased bone radiotracer
uptake.
120. multiple circular and ovoid
sclerotic opacities
appear to be parallel each other
and to the long axis of the
bone.
A periarticular distribution
121. The main clinical
significance is that
these may be
mistaken for
sclerotic metastases.
their classic
distribution and
appearance will
distinguish them
readily from evil
entities like mets.
osteopoikilosis of the pelvis and
proximal femurs
122. May be related to other sclerosing dysplasias
including,Osteopathia striata.
melorheostosis.
focal sclerosis.
and when seen in combination with them, is termed
"MIXED SCLEROSING BONE DYSTROPHY."
