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MSK series


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osteoporosis

Osteoporosis is defined as a condition 
characterized by diminished but otherwise 
normal bone.

(T-score of –2.5 or less) as measured with dual-
energy x-ray absorptiometry(DEXA).


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An osteoporotic state may arise either when 
bone 

formation is inadequate

or when bone 

resorption exceeds bone formation

.

Osteoporosis may be a 

local

phenomenon (as in 

disuse osteoporosis) or a 

generalized

condition.


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CAUSES 

Primary/senile osteoporosis 

– Most common, increased 

risk with low body weight, Postmenopausal

Secondary osteoporosis (5%) 

– From 

-

drugs

(cortisol/steroids, heparin) 

-

congenital

(OI, homocystinuria,)

-

endocrine disorders 

(hyper/hypo-thyroidism, 

hyperparathyroidism, Cushing’s disease)
-

GI 

(malnutrition, malabsorption,vitamin C/D deficiency) 

-

immobilization

.


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يهببعسث


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Rickets and osteomalacia

Rickets is the interruption of orderly 

development and mineralization of growth 
plates.

Osteomalacia is inadequate or abnormal

mineralization of osteoid in cortical and 
trabecular bone.


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Radiographic findings of Rickets

Extremity

: Widened growth plate;

irregularity and osteopenia along
metaphyseal side of growth
plate; fraying , bowing.

Chest

: Rachitic rosary

Skull

: Flat occiput, widened

sutures, basilar invagination


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RICKETS


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Rachitic Rosary-enlarged costochondral junctions of

the ribs in rickets resembling a string of rosary beads.


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Rickets. There is cupping and fraying of all of the metaphyses 

(white arrows) in this skeletally-immature child.


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- Looser zones are distinctive feature of osteomalacia.
- Looser zones are the result of deposition of 
unmineralized osteoid at sites of stress . 

-

- zones can occur with 

no or minimal trauma, 

are 

often bilateral and symmetric, and appear as 
transverse lucent bands oriented at 

right angles to 

the cortex 

that only span a 

portion

of the bone 

diameter.

- Although known as 

pseudofractures

, Looser zones are 

a type of insufficiency fracture
.


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Some of the common locations of Looser zones 
are similar to those of stress fractures, such 
as:

- inner margin of the femoral neck
- pubic rami
- lateral scapula


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Osteomalacia with biconcave (fish vertebra) with endplate 

depression.


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Hyperparathyroidism 

- Hyperparathyroidism is a pathologic state of elevated
parathyroid hormone concentrations, which causes

increased bone resorption.

- Primary hyperparathyroidism is a state of 

autonomous

parathyroid hormone secretion by the parathyroid
glands and lack of feedback inhibition by serum
calcium.
- Primary hyperparathyroidism is usually caused by a

parathyroid adenoma

, but in approximately 10% of

cases, it is a result of 

four-gland hyperplasia

, and in

extremely rare cases, primary hyperparathyroidism is
due to 

parathyroid carcinoma


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Secondary hyperparathyroidism 

Secondary hyperparathyroidism is more 

common than primary hyperparathyroidism 
and is a 

response to low serum calcium 

levels.

The most common cause is 

chronic renal 

failure .

Secondary hyperparathyroidism can also be 

observed in vitamin D deficiency and dietary 
calcium deficiency .


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Skeletal manifestations 

- In 95% of patients with hyperparathyroidism, skeletal
findings are most readily recognized in the hand.

- The pathognomonic 

subperiosteal bone resorption 

in

hyperparathyroidism begins at the radial aspects of the
middle phalanges of the middle and index fingers as
and at the distal phalangeal tufts as 

acro-osteolysis

.

- Subperiosteal resorption can also be observed in the
ribs, 

loss lamina dura 

(bone that surrounds the tooth

sockets), .


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Loss of Lamina dura in Hyperparathyroidism.


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- In the skull, bone resorption is described as a salt-and-
pepper appearance

- Brown tumors, also known as osteoclastomas, are lytic
lesions that result from the parathyroid hormone 
activate osteoclasts.
- Brown tumors are generally solitary but can be 
multifocal and are at risk for pathologic fracture.
- Brown tumors commonly involve the facial bones, ribs, 
pelvis, and femoral bone

- Treatment of hyperparathyroidism may also lead to 
resolution of brown tumors.


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hyperparathyroidism the skull takes on a mottled or "pepper 

pot" appearance.


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Brown tumor 


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Renal osteodystrophy 

- Renal osteodystrophy refers to the complex of findings
observed in the setting of chronic renal insufficiency

- These include the findings of:  

osteomalacia

(and rickets 

in children) and 

secondary hyperparathyroidism

- In patients with chronic renal insufficiency, radiographs
may show a 

diffuse increase in bone radiodensity 

a finding

that is seen more often in the axial skeleton, which has
more trabecular bone than cortical bone .Despite the
increased radiodensity, the bone is structurally 

weak

and

prone to stress fractures 

.


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- The spine often demonstrates a characteristic 

striped

appearance (alternating bands of 

increased density along the endplates and 
decreased density in the central portion of the 
vertebral body), which is also known as the 

rugger-jersey spine


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hypoparathyroidism

- Hypoparathyroidism is caused by iatrogenic injury to the 
parathyroid glands during thyroid surgery or excision of 
the parathyroid glands

- End-organ insensitivity to parathyroid hormone is called

pseudohypoparathyroidism

and has different radiographic

Findings 

Radiographic findings of Hypoparathyroidism reflect an
overall increase in bone mass, including 

generalized or

localized osteosclerosis 

and 

thickening of the calvaria


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Acromegaly 

- Acromegaly is due to excess growth hormone secretion
from the anterior lobe of the pituitary.

Radiographic Findings:

-

Hand

: Spade-shaped tufts, tubulation of phalangeal

shafts, exostoses, widened joint spaces, sesamoid
enlargement.
-

Feet

: Heel pad thickness > 25 mm in men and > 23 mm in

women, skin thickening, tendon insertion ossification

- Skull

:Thick skull bones; enlarged sella; frontal bossing;

prominence of frontal and maxillary sinuses, 
, prognathism (protrusion of jaw); enlargement of the 
mandible.


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رفعت المحاضرة من قبل: Bakr Zaki
المشاهدات: لقد قام عضو واحد فقط و 77 زائراً بقراءة هذه المحاضرة








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