2. Metabolic bone disease:
Bones made up of calcium hydroxyapatite mineral deposited on a matrix/osteoid
of primarily collagen. Bone is a reserve for calcium and phosphate, helping to keep
serum levels constant, also maintained by gut absorption and renal tubules.
Parathyroid hormone (PTH) – Produced by the parathyroid glands, increases
serum calcium at proximal tubules (enhanced phosphate excretion and calcium
reabsorption), osteoclast-mediated surface bone resorption (increasing serum
calcium and phosphate), enhanced synthesis of 1,25-hydroxy-vitamin D. Net result
is increase in serum calcium while keeping phosphate stable.
Vitamin D – Endogenous (D3 synthesized by skin exposed to UV) or exogenous (D2
most, from dietry sources) which is converted by liver to 25-hydroxy-vitamin D and
by kidney to active form 1,25-hydroxy-vitamin D(increased in hypophosphataemia
and hypocalcaemia). In bones it causes transcription of osteocalcin, osteopontin
and alkaline phosphatase to release calcium and phosphate, promoting
maturation and mineralization of osteoid matrix (with parathyroid hormone
cofactor). In gut it causes production of calcium-binding protein, in kidney
increases phosphate resorption also requiring parathyroid hormone cofactor. It
inhibits release of PTH. Net result increases both serum calcium and phosphate.
Calcitonin – Hormone produced primarily by parafollicular cells of
thyroid, physiologic antagonist to parathyroid hormone.
ALP is raised in bone production; urine hydroxyproline raised in bone resorption.
3. Table of content
Osteoporosis.
Osteomalacia and rickets.
Hyperparathyroidism (HPT).
Renal Osteodystrophy.
Hypoparathyroidism.
Pituitary Hyperfunction.
Thyroid Dysfunction.
Osteosclerosis.
Paget Disease.
Fluorosis, Hypervitaminosis A and D.
Heavy Metal Poisoning.
Scurvy.
Gaucher’s Disease.
4. Osteoporosis
Reduced quantity in otherwise normal bone quality (c.f osteomalacia).
Osteopenia is reduced bone mineral density (BMD) (encompassing
osteoporosis and osteomalacia). Bone loss exceeds bone production. Peak
bone mass is achieved during young adulthood, with magnitude depending
on genes, physical activity, muscle strength, diet, hormonal state. Small
deficits in bone formation after peak accrue over time, normally ~0.7% per
year.
Primary/senile osteoporosis – Most common, increased risk with low body
weight, less weight-bearing exercise, whites and Asians. Osteoblasts have
reduced proliferative and synthetic potential. Postmenopausal osteoarthritis
from reduced estrogen. Bone loss begins in 30s in women; 40s-50s in men. Tx
calcium, estrogen, bisphosphonates (inhibits osteoclasts).
Secondary osteoporosis (5%) – From drugs (cortisol/steroids, heparin,
phenytoin, alcohol, smoking), congenital (OI, homocystinuria, ochronosis),
endocrine disorders (hyper/hypo-thyroidism, hyperparathyroidism, Cushing’s
disease, type 1 diabetes, Addison disease), neoplasia (multiple myeloma,
carcinomatosis), GI (malnutrition, malabsorption, hepatic insufficiency,
vitamin C/D deficiency), immobilization, pulmonary disease, anemia.
5. Bone mineral densitometry (BMD) – Dual energy x-ray absorptiometry (DEXA)
uses two energies which have different attenuation coefficients for bone,
muscle and fat; compares density (g/mL) from several sites (usually L-spine,
proximal femur ± wrist). Z-score is the standard deviations above or below
average bone mineral density for that age and sex. T score compares against
peak young normals of same sex. T score >-1 normal; -1 to -2.5 defined as
osteopenia; <-2.5 osteoporosis. Each T score below normal increases fracture
risk X3. Quantitative CT densitometry is more sensitive (can measure more
affected trabecular bone. On XR 30-40% bone mineral loss is required before
becoming subjectively apparent. US calcaneous can also be used. Cortical
thinning (esp. 2nd & 3rd metacarpal mid-diaphysis, where cortex should be
>/=50% of bone width). Reduced quantity and thickness of trabecula (in
proximal femur order of loss is secondary tensile, primary tensile, secondary
compressive, then primary compressive). Accentuation of stress/load-bearing
trabeculae (last to be resorbed). Cortical tunneling (Intracortical lucencies)
parallel to long axis. Insufficiency fractures esp. spine (anterior wedge,
biconcavity of endplates or generalized loss of height), hip, proximal humerus,
distal forearm. Bone bars (reinforcement lines) – transverse trabeculae in
diaphysis/metaphysis. Exaggerated contrast of vertebral endplates and
vertical trabeculae.
6. Regional osteoporosis is often symptomatic, may be radiographically aggressive.
Transient regional osteoporosis (TRO, regional migratory osteoporosis) – Multiple
consecutive joints with marrow edema, esp. lower limb distal to knee. Self-
limiting.
Transient osteoporosis of the hip (TOH) – Middle-aged men and pregnant women
(usually L hip). Sudden onset hip pain with marrow edema, joint effusion,
osteoporosis, increased uptake on bone scan. Self-limited, resolving in several
months, Tx conservative. ?Form of TRO.
Reflex sympathetic dystrophy (RSD) – Dysfunction of sympathetic nervous system
associated with trauma, neurologic and vascular events. Severely reduced BMD,
soft tissue swelling, hyperesthesia then atrophy and contracture.
Hyperemia – Induces osteoclastic activity. From inflammatory arthropathy,
hypervascular tumours, RSD, healing fractures.
Disuse osteoporosis – From immobilization, commonly after fracture and casting.
May be aggressive with Intracortical lucencies, metaphyseal band lucencies
(relative hyperaemia from rich blood supply), subcortical/subchondral resorption.
May occasionally mimic a permeative lesion (pseudopermeative), but cortex in
true medullary lesion remains solid (c.f multiple small holes). DDx haemangioma
(cortical holes from focal hyperemia -> focal osteoporosis or blood vessels
tunneling through) or radiotherapy (death of cortical osteocytes -> large lacunae,
relatively larger cortical holes).
7. Radiographic features
Decreased bone density can be appreciated by decreased cortical
thickness, loss of bony trabecula in early stages in radiography. Bones like
vertebra, long bones (proximal femur), calcaneum and tubular bones are
usually looked for evidence of osteoporosis.
Plain film
not a sensitive modality, as more than 30-50% bone loss is required to
appreciate decreased bone density on radiograph
vertebral osteoporosis manifests as:
pencilling of vertebrae
loss of cortical bone (picture frame vertebra) and trabecular bone
(ghost vertebra)
compression fractures and vertebra plana
loss of trabecula in proximal femur area which is explained by Singh's
index (which can also be seen in the calcaneum
in tubular bones (especially metacarpals), there will be thinning of cortex
cortical thickness <25% of whole thickness of metacarpal signifies
osteoporosis (normally 25-33%)
8. Bone mineral density measurement
BMD is the method of estimation of calcium hydroxyapatite.
Multiple x-ray based, gamma-ray based and ultrasonic methods are
available:
radiographic absorptiometry (RA)
single photon and x-ray absorptiometry(SPA)
dual energy x-ray absorptiometry (DEXA)
most commonly used and most reliable
quantitative computed tomography can be used
Magnetic resonance imaging (MRI) and computed tomography (CT)
are such new techniques which potentially may provide information
pertaining to bone density and structure as well as to occult fracture
detection. For example, quantitative CT (QCT), peripheral QCT and
quantitative MRI are promising tools for the measurements of the
bone density. Micro-CT and magnetic resonance microscopy are
potentially available tools to image and quantify the three-
dimensional structure of trabecular bone.
9. Two views of the lumbar spine taken 1 year apart demonstrate rapidly developing
osteoporosis and multiple compression fractures in this patient on exogenous steroids
13. The sites scanned routinely, and from which diagnosis of
osteoporosis is made, are a | lumbar spine L1–
L4, b | proximal femur neck (oblong box) and total hip.
Additional parameters such as neck shaft angle, the angle
at the intersection of the line drawn parallel to cortices of
proximal femoral shaft and the broken line of the hip axis
length; c | hip axis length, which is the length of the broken
line drawn parallel to the margins of the femoral neck and
extending from the inner margin of the pelvis to the outer
margin of the lateral femur below the greater trochanter;
and hip strength, calculated from the distribution of bone
mineral around a central axis in sites at the femoral neck,
inter-trochanteric and proximal femoral shaft regions, can
be measured. Both biomechanical properties of stress
strain index and moment of inertia can be derived
automatically from DXA scans of the hip, but they remain
research tools. In children for whom the use of DXA in the
normal measurement sites is precluded by deformity or
contracture, d | lateral DXA of the distal femur has been
proposed, and the regions from which BMC and areal BMD
are measured are indicated in this lateral DXA image of a
child's femur. e | Lateral Vertebral Fracture Assessment
images obtained on DXA scanners are increasingly used for
identification of vertebral fractures. In this lateral spinal
image a grade 3 severe fracture of T11 (arrow) is visible.
Such images also have the potential to enable grading of
abdominal aortic calcification lying anterior to lumbar
vertebrae (arrowhead). f | Whole-body DXA scans provide
total and regional BMC, BMD and body composition of
lean muscle and fat mass, in addition to android (A) and
gynoid (G) body composition. Abbreviations: DXA, dual
energy X-ray absorptiometry; BMC, bone mineral content.
14. A 80 years old female with osteoporotic compression fracture of several vertebral bodies of the thoracic spine and lumbar
spine (latter not shown). The MRI shows the fractures with kyphoplasty/vertebroplasty (B: T1-weighted, C: T2-weighted,
D: short T1 inversion recovery). The CT and corresponding SPECT/CT (A and E) are showing the status post
kyphoplasty/vertebroplasty. Note the elevated uptake in the cover plate of Thoracic segment 8 showing a fresh fracture.
15. Osteomalacia
Reduced bone quality with excess nonmineralised osteoid most from
lack of vitamin D. Most commonly renal from reduced 1-hydroxylation
or renal tubular disorders (vitamin D resistant rickets e.g X-linked
hypophosphataemia and cystinosis); other causes include
dietary/malabsorption (Crohn’s, small bowel resection), biliary
(reduced absorption) and hepatocellular disease (reduced 25-
hydroxylation), receptor resistance (rare), drugs (phenytoin,
Phenobarbital), oncogenic form (rare, hormones from tumours e.g
hemangiomas, NOF, giant cell tumour of bone interfere with tubular
resorption of phosphate).
Findings almost identical to osteoporosis with demineralization. Bones
are lucent, coarsened, smudgy. Looser fracture/zone (pseudofractures)
– uncommon but pathognomonic fracture through large
undermineralised osteoid on concave aspect of bone (compression, c.f
Paget’s convex), perpendicular and not crossing entire width esp. in
axillary margins scapula, ribs, pubic rami, proximal femur, dorsal
proximal ulna.
16. Rickets – Osteomalacia: Rickets is occur in immature skeleton
with undermineralised metabolically active sites (metaphyses
esp. proximal/distal femur, proximal tibia, proximal humerus,
distal radius). Osteomalacia occurs in adult affects mature
bone. Flared irregular frayed metaphyses (become dense with
treatment), widened irregular zones of provisional
calcification (physes), bending of long bones, rachitic
rosary in ribs (diffuse costochondral enlargement), bizarre
deformities (repeated insufficiency fractures), short squat
bones, SH1 fractures (esp. bilateral SUFE). From renal disease,
biliary disease, dietary insufficiency. DDx metaphyseal
dysplasia (growth plate widening due to error in enchondral
ossification, normal bone mineralization and biochemistry),
hypophosphatasia (severe osteopenia, wide growth plates,
multiple fractures, low ALP c.f elevated in rickets).
19. X-ray appearances of the wrist and knee in osteomalacia
(A) before treatment (B) after six months of treatment
20. Osteomalacia: Hand-wrist radiographs demonstrated decreased opacity suggesting of poor bone mineralization and sponge like
appearance in the X-ray a and b]. Pelvic radiograph showed altered bone mineralization with reduced bone opacity along with
pseudo fractures or incomplete fractures in the pelvis c]. Postero-anterior cephalometric projection view showed hypoplastic
maxillary sinus d]. An orthopantomogram was done which showed generalized sever bone loss (up to the apex of tooth),
impacted lower left second premolar along with thinning of mandibular cortex e]. Lateral view of skull demonstrated increased
mandibular angle and maxillary micrognathia, along with thickening of the diploic space when compared with normal
23. Rickets
Rickets of the knees demonstrates bowing of the femurs,
metaphyseal cupping and fraying, coarsening of the
trabecular pattern, increase in distance between end of shaft
and epiphyseal center, poorly ossified epiphyseal centers.
24. Rickets. There is cupping and fraying of all of the metaphyses (white arrows) in this skeletally-immature child.
25. Rickets with widening and irregularity of the growth plate ("fraying")
widening of the metaphyseal end of the bone ("splaying")
concavity of the metaphysis ("cupping")
28. Hyperparathyroidism (HPT)
Excessive parathyroid hormone (PTH) causes osteoclastic resorption,
osteoporosis, osteomalacia. Affects cortical bone more than cancellous bone.
Primary HPT – From parathyroid adenomas/hyperplasia or rarely
adenocarcinoma. Multiple adenomas in 10%. May be associated with MEN I or
MEN II. Elevated serum calcium and reduced phosphate. Generalized weakness,
urolithiasis, peptic ulcer disease, pancreatitis, bone and joint pain. 40% have
skeletal abnormality on XR.
Secondary HPT (more common) – Mostly from renal failure with reduced capacity
to excrete phosphate causing elevated serum phosphate and non-measurable
reduced calcium promoting PTH secretion. Tends to be milder than primary HPT.
Tertiary HPT – Autonomous PTH production after correction of long-standing
secondary HPT.
Subperiosteal resorption (pathognomonic esp. radial aspect 2nd and 3rd middle
phalanges, medial humerus, femur, tibia, superior/inferior ribs, lamina dura of
teeth), intracortical, endosteal (can mimic marrow dyscrasias), trabecular,
subchondral (sacroiliac, AC, sternoclavicular, TMJ, symphysis pubis) and
subligamentous (trochanters, ischial tuberosities, inferior calcaneous, distal
clavicle, elbow) bony resorption. Osteoclasts tunnel centrally along trabeculae
(dissecting osteitis) causing osteopenia.
29. Skull salt-and-pepper appearance. Tuft resorption/acro-
osteolysis. Risk of osteopenic fractures. Soft tissue
calcification, periostitis and osteosclerosis (usually diffuse,
sclerotic bands at vertebral endplates =rugger jersy spine)
more common in secondary HPT. CPPD and Brown
tumours more common in primary HPT. Prone to tendon
and ligament laxity and rupture. Bone scan increased
uptake in brown tumours and Looser fractures.
Brown tumours in 40% of primary HPT (but more
commonly secondary due to increased prevalence),
accumulations of osteoclasts, hemorrhage, vascularity
and fibrous tissue, can be multiple, tend to heal after
treatment of HPT. Eccentric, cystic often expansile, may
have aggressive appearance.
30. Subperiosteal resorption that has resulted in severe tuftal resorption
. Also, note the subperiosteal and intracortical resorption.
31. Radiograph of the phalanges in a patient with primary hyperparathyroidism. This image
demonstrates subperiosteal resorption that has resulted in severe tuftal resorption (arrows).
34. Radiograph of the distal femur in a patient with primary hyperparathyroidism. This image shows
scalloped defects along the inner margin of the cortex, which denote endosteal resorption.
35. Radiograph of the humerus and mid femur diaphysis in a patient with primary
hyperparathyroidism. This image depicts a brown tumor. Note the osseous expansion
and lucency of the proximal humerus. Brown tumors can have varied appearances.
36.
37. In hyperparathyroidism the skull takes on a mottled or "pepper pot" appearance.
The spine shows sclerotic bends on plain x ray. This is known as a "rugger jersey" spine.
39. Technetium-99m sestamibi scan (99mTc MIBI) in a patient with multiple endocrine
neoplasia syndrome type 1 (MEN 1). This image demonstrates persistent abnormal
activity of the inferior right parathyroid gland that is consistent with an adenoma.
40. Renal Osteodystrophy
Osteomalacia (reduced 1-hydroxylation), secondary
hyperparathyroidism (hyperphosphataemia), osteosclerosis, growth
retardation and osteoporosis (metabolic acidosis stimulates bone
resorption and release of calcium hydroxyapatite) from chronic
renal failure. Dialysis can also cause bone toxicity (aluminum
interferes with calcium hydroxyapatite deposition) or amyloidosis,
also at risk of osteomyelitis and septic arthritis due to chronic
immune suppression, AVN from steroids. Types include high-
turnover osteodystrophy (resorption > formation), low-
turnover/aplastic disease (adynamic bone) and mixed pattern
(most common). Areas of demineralization and osteosclerosis (esp
vertebral endplates = rugger jersey spine, may be diffuse. Profuse
soft tissue calcifications including vascular and para-articular (may
be milk of calcium, may be massive = tumoral calcinosis).
Insufficiency fractures and Looser’s zones.
42. Lateral radiograph of the leg in a child
with chronic renal failure reveals anterior
bowing of the distal tibia.
Anteroposterior radiograph of the hip in a dialysis
patient reveals erosion of a large portion of the medial
femoral neck and trochanteric region from amyloid
deposition (arrowheads) with a pathologic fracture in the
basocervical portion of the femoral neck (arrow).
44. Oblique radiograph of the hand in a dialysis
patient reveals multifocal, large, amorphous
calcific deposits (tumoral calcinosis) around the
hand and wrist (arrows).
Anteroposterior radiograph of the fingers in a patient with
chronic renal failure reveals calcification of the vasculature
(arrows), as well as resorption of the distal tufts
(arrowheads).
45. Chronic renal failure reveals chondrocalcinosis of the menisci,
triangular fibrocartilage and calcification of the patellar tendon
46. Renal failure reveals subperiosteal resorption along
the radial aspect of the middle phalanx (arrows), as
well as resorption of the distal tuft (arrowheads).
Chronic renal failure reveals subchondral and
subperiosteal bone resorption predominating
at the joint margins (arrows), which resembles
the erosions of rheumatoid arthritis.
47. Chronic renal failure reveals subperiosteal resorption
at the proximal medial aspect of the bone (arrow).
Renal failure reveals cupping and fraying of the metaphysis and irregularity
of the epiphyseal margins compatible with renal rickets (arrowheads). The
coarsened trabeculae are a feature of osteomalacia (arrows).
48. Chronic renal failure and rachitic rosary reveals abnormal widening
of the anterior ribs at the costochondral junctions (arrows).
Anteroposterior radiograph of the distal forearm in a
patient with chronic renal failure reveals an expansile
lytic lesion (brown tumor) in the distal ulna (arrows).
49. Chronic hemodialysis
shows a generalized
reduction in bone density,
associated with cortical
thinning and coarsening
of the trabecular pattern.
Radiographs of the knees
show a pseudo-fracture
(yellow arrow) and
"brown cysts" (orange
arrow). Also noted are
coarse trabecular
patterns.
50. Chronic hemodialysis shows a generalized reduction in bone density, associated with cortical thinning and coarsening of the
trabecular pattern. Pseudo-fractures/Looser zones are evident in the left lower femoral shaft and along the medial aspect of
the left femoral neck (yellow arrows). There is bilateral protrusio acetabuli, which is a feature of bone softening (white
arrow). There are multiple centrally compressed vertebral bodies giving a "cod fish" appearance. Scoliosis of the thoracic
spine secondary to bone softening is noted. There is fairly extensive nephrocalcinosis related to secondary
hyperparathyroidism (red arrows). Relative preservation of the vertebral end plates gives rise to a "Rugger Jersey" spine.
51. Hypoparathyroidism:
Parathyroid gland deficiency from parathyroid gland resection.
Hypocalcaemia and hyperphosphataemia with irritability,
seizures, tetany. Occasional calvarial thickening, subcutaneous
and basal ganglia calcification, osteosclerosis (localized or
generalized), rarely osteoporosis.
Pseudohypoparathyroidism – Congenital target cell resistance
to PTH, normal glands. Hypocalcaemia but high PTH. Obesity,
round facies, short stature, brachydactyly (tubular bones of
hands and feet short esp. 1st 4th and 5th metatarsals and
metacarpals), early growth plate closure, thick calvaria,
intracranial and soft tissue calcifications, small
osteochondromas at right angles to shafts.
Pseudopseudohypoparathyroidism – No parathyroid or
biochemical abnormality, patients resemble
pseudohypoparathyroidism.
53. CT scan of a patient with hypoparathyroidism. There are calcifications of the
basal ganglia and subcortical white matter. There is no edema or mass effect.
60. Abnormalities of the Hand and Wrist, Widening of MCP joint spaces Soft tissue thickening Carpal cysts Pathophysiologic
correlation: Excessive growth hormone, increased chondrocytic activity, proliferation of articular cartilage (cartilage
hypertrophy), widening of articular space Carpal cysts result suggest bone degeneration Broadened phalangeal tufts
61. Abnormalities of the Foot: Soft tissue enlargement, widening of the MTP
joints, prominence of terminal phalangeal tufts and bases, pseudoforamina.
67. A: Skull X ray, lateral views, in a two- year-old child
and 18-months old child demonstrating persistent wide
anterior fontanelle, mild degree of brachycephaly in a
relatively underdeveloped skull base with increased
bone density, underdeveloped paranasal sinuses and
slightly hypoplastic facial bones, enlarged sella turcica
(Cherry sella), few wormian bones along lambdoid
suture, relatively narrowed deploic space of parietal
bones and overcrowded teeth. B : AP view of knee
demonstrating epiphyseal dysgenesis [irregularity and
mild stippling] of the lower femoral and upper tibial
epiphyses which are relatively small; and a delayed
appearance of the upper fibular epiphysis for age of
the patient. C, D. Plain X ray of the pelvis and both hips
in a two-year-old child (C ) and five-year-old (D )
demonstrating epiphyseal dysgenesis of the upper
femoral epiphyses (irregular flattened upper femoral
epiphysis which are small for age of the patient under
developed) with relatively shallow acetabular roofs
and mild coxa vara deformity and relatively small
(hypoplastic) iliac bones. E,F : Plain X ray of
dorsolumbar region of two different patients
demonstrating flattening of the vertebral bodies with
relative osteoporosis leading to the appearance of
"picture framing" of vertebral bodies (E, and relatively
wide disc spaces with typical bullet shape appearance
of vertebral bodies (LV1 and LV2 ) and relatively small
body of LV1 with anterior subluxation of DV12 over LV1
leading to smooth gibbus deformity (F).
68. A, Normal 6-year-old
child (left) and a congenitally
hypothyroid 17-year-old
child (right) from the same village
in an area of endemic cretinism.
Note especially the short stature,
obesity, malformed legs, and dull
expression of the mentally retarded
hypothyroid child. Other features
are a prominent abdomen, a flat
broad nose, a hypoplastic
mandible, dry scaly skin, delayed
puberty, and muscle weakness. X-
ray films of the hand of a normal
13-year-old child (B) and that of a
13-year-old child suffering from
hypothyroidism (C). Note that the
child with hypothyroidism has a
marked delay in development of
the small bones of the hands, in
growth centers at either end of the
fingers, and in the growth center of
the distal end of the radius.
70. Osteosclerosis
Diffuse increased bone density. Causes include:
Metastases – Usually prostate or breast, usually has some component of
cortical destruction or lysis.
Paget disease – Paget's rarely diffusely sclerotic, usually causes bony
enlargement, most common in pelvis with thickened ileopectineal line. Can
occur in any bone. Lytic, sclerotic and mixed lytic-sclerotic phases. Lytic phase
has sharp flame-shaped or blade-of-grass leading edge. In long bones (except
tibia) always starts and bone end.
Renal osteodystrophy, or any cause of HPT – Most cause osteopenia, 10-20%
osteosclerosis (unknown cause). Must have subperiosteal bone resorption.
(idiopathic myeloid metaplasia) – Progressive fibrosis of marrow
Myelofibrosis, >50yo, anemia, marked splenomegaly, extramedullary
hematopoiesis.
Osteopetrosis – Hereditary, extremely dense bones. Congenital form at birth
can be lethal, anemia, jaundice, hepatosplenomegaly, infections. Tarda form
(older children, adults) causes bone-in-bone appearance of vertebral bodies
(small replica inside), sandwich vertebrae(densely sclerotic endplates, denser
and sharper than rugger jersey).
71. Pyknodysostosis (Toulouse-Lautrec syndrome) – Congenital,
short stature, hypoplastic mandibles, acro-osteolysis with
sclerosis (pathognomonic, pointed dense distal phalanges).
Mastocytosis – Rare uniformly increased bone density,
thickened small bowel folds with nodules, urticaria
pigmentosa.
Fluorosis – Rare, from chronic intake of fluoride.
Ligamentous calcification esp. sacrotuberous ligament.
Sickle cell disease – Occasionally. Also causes bone infarcts,
step-off (Lincoln log, H-shaped, fish vertebrae) deformities
of vertebral endplates with central depression, AVN of hip.
Athletes – Increased cortical thickness causing apparent
diffuse osteosclerosis. Hypertrophy of bone and muscle.
75. Osteopoikilosis. Black arrows point to numerous sclerotic bone islands
surrounding the hip joints in a pattern characteristic of osteopoikilosis. CT images
of the same patient show the well-circumscribed lesions in the femurs and pelvis.
76. (a) X-ray of spine shows dense and sclerosis at the margins of the vertebral bodies in alternating parallel sclerotic and lucent bands (sandwich
vertebrae or "rugger-jersey" spine). (b) Dual-energy X-ray absorptiometry scan shows dense sclerosis at the margins of the vertebral bodies
and the T-score was high at +6.5 (b and c). On computed tomography (CT) component of single-photon emission computed tomography/CT,
there is dense sclerosis at the margins of the vertebral bodies (bone-in-bone appearance) and within the pelvic bones (d and e)
77. Paget's Disease -- pelvis. Frontal radiograph of the pelvis demonstrates
the classical triad of thickening of the cortex (blue arrow), accentuation
of the trabecular pattern (red circle) and increased density of the bone.
83. Skeletal sickle cell anemia. Expanded medullary cavity. The diploic space
is markedly widened due to marrow hyperplasia. Trabeculae are oriented
perpendicular to the inner table, giving a hair-on-end appearance.
84. 30 year progression of calvarial changes in male homozygous sickle cell anemia patient. A, At 1 year
old, expansion of diploe begins in the posterior frontal area and is definitely identifiable. B, At age 2
expansion is prominent. At ages 23 (C) and 30 (D), false hair-on-end” sign appears.
85. Skeletal sickle cell anemia. Osteonecrosis in the same patient as in the previous image. Coronal T1, T2-
weighted MRI shows a serpentine area of low signal intensity and additional focal areas of abnormal
low signal intensity in the femoral head; these findings reflect collapse of bone and sclerosis.
89. Paget Disease
(Osteitis deformans). Chronic progressive, not metabolic but
similar, ?etiology ?paramyxovirus in osteoclasts. More
frequent in extreme north and south latitudes (low incidence in
Asia and Africa), late adulthood ~70yo (rare <40yo, affects 10%
of >80yo), M:F 2:1, FHx (15-40% AD), decreasing over time.
Localized to a few bones, can cross joints, monostotic in 15%.
Can be any bone esp. skull, spine, pelvis, femur; but extremely
rare in fibula, ribs, small bones of hands/feet. Histologically
mosaic pattern of lamellar bone, like a jigsaw puzzle. Stages
often coexistent including stage I hot, osteolytic; II mixed lytic
and blastic (osteoblastic activation in response to resorption);
III burnt-out quiescent sclerotic phase when new equilibrium is
established. Elevated ALP and hydroxyproline but normal
phosphorous and calcium.
90. Usually begins at bone ends, extending ~1cm/yr to diaphysis (may start in
diaphysis in tibia) with lytic sharply defined leading edge in flame-shape
or blade-of-grass (osteoporosis circumscripta in skull). Mixed lytic and
sclerotic phases behind the leading edges. Triad of bone expansion,
cortical thickening, trabecular thickening. Picture frame vertebra – mixed
lytic and sclerotic phase in spine. Cotton wool skull – stage II mixed
sclerosis and lysis. Conductive hearing loss from otosclerosis with
enlargement and reduced function of ossicles; sensineural hearing loss
from osseous expansion narrowing IAM. Pagetic bone is soft, prone to
fracture and deformity. Osteoarthritis in >50%. Platybasia with basilar
skull impression/invagination in 1/3. Spinal stenosis. Neoplastic
transformation to osteosarcoma/fibrosarcoma in 1% (5-10% of severe
polyostotis disease) indicated by new-onset pain; in skull most commonly
GCT. Higher risk of osteomyelitis (?hypervascularity), CPPD, gout, rarely
high-output cardiac failure, anemia, metastases in Pagetic bone. Rapid
osteolysis may occur when equilibrium between production and lysis is
disrupted in disuse. Banana/chalk stick fractures – transverse distraction
insufficiency fractures on convexity of deformed bone. Shepherd's crook
deformity – varus proximal femur.
94. Paget’s disease of T11 and T12 showing an increased amount of high MR signal (solid white arrow) in the posterior epidural space at these levels on a
sagittal T2-weighted, b sagittal T1-weighted and c axial T1-weighted images. This can be mistaken for epidural lipomatosis. However, the d CT
sagittal and e axial images demonstrate this to be due to the fat density (solid white arrow) within the expanded posterior neural arch involved in
PD. The axial images (c,e) were obtained at the level of the tip of the solid arrows on sagittal images. There is also fusion of the vertebrae (dashed
arrow) across the intervertebral disc. The combination of anterior and posterior vertebral involvement in this case resulted in severe spinal canal
narrowing and cord compression. Note the high T1 signal indicating a high fatty marrow content within the pagetic T11 and T12 vertebra.
95.
96. Fluorosis, Hypervitaminosis A and D
Over ingestion of fluoride, vitamin A or D. Retinoid arthropathy
– retinoic acid derivatives related to vitamin A, used for acne.
Increased bone density and periostitis from metastatic
deposition of calcium salts.
Fluorosis – Flowing ossification of ALL, mottled teeth highly
resistant to caries.
Hypervitaminosis A – Flowing ossification of ALL,
hydrocephalus, prominent periosteal new bone formation
(mimics Coffey's disease) usually sparing mandible, jaundice.
Hypervitaminosis D – Hypercalcemia, hypercalciuria,
phosphaturia, soft tissue calcification, cortical and trabecular
thickening, dense skull, widened provisional zone of
calcification in children.
97. Radiographic features
Plain film/CT
Described features include:
increased bone density: osteosclerosis
osteopaenia/osteoporosis
trabecular blurring or haziness
compact bone thickening
periosteal bone formation and
ossification of the attachments of tendons, ligaments, and muscles
interosseous membrane calcification
ossification of the posterior longitudinal ligament
Involvement of the axial skeleton is characteristic, and changes are most marked
in the spine, pelvis and ribs.
In early fluorosis, the first changes are bone deposition and thickening at the
junctions of trabeculae. This is seen as sand like, granular, or particle like bone
structure on radiographs.
In more advanced fluorosis, the trabeculae are more generally thickened because
of new bone formation on the trabecular surface. At this stage, radiographs show
thickening and condensation of trabeculae, with coarse reticulum or woven bone
striations.
If the trabeculae are fused, focal round densities are seen in the medullary bone.
100. Heavy Metal Poisoning
Several heavy metals esp. lead damage osteoclasts, increasing bone
density and undertubulation in metaphyses. Dense metaphyseal
bands are common normally in metaphyses of growing children, but
pathological in proximal fibular and distal ulna (DDx healing rickets,
hypervitaminosis D, treated hypothyroidism, rarely scurvy).
Lead poisoning. Plain abdominal radiograph in a 3-year-old patient
shows multiple metallic particles due to ingested flakes of lead paint.
101. Lead poisoning. Opaque metaphyseal bands in the lower femur, upper
tibia, and the upper fibula secondary to lead poisoning in a child.
102.
103. Scurvy
Rarely seen now, vitamin C defiency limiting
collagen formation (bone matrix, cartilage,
tendon, ligaments). Diffuse bone
demineralization, insufficiency fractures,
subperiosteal hemorrhage with subsequent
ossification. Weinberger's sign – sclerotic
epiphyseal rim from disorganized bone at
centre of ossification. Frenkel’s line – dense
metaphyseal line. Pelkin’s fracture –
metaphyseal corner fracture.
106. Scurvy, Anteroposterior (a) and lateral (b) X-rays of the knees showing varus deformity. Visible abnormalities include
ground glass osteoporosis, thinning of the cortices, lucencies at metaphysis (Trummerfeld zone, black arrow), small
corner fractures (Pelkan’s spur, solid arrow), and dense zone of provisional calcification in the physis.
107. Scurvy, Anteroposterior (a) and lateral (b) X-rays of the hands and wrists showing severe osteopenia of the epiphyses of the
phalanges (dotted arrow), metacarpals and the carpal bones, epiphyseal separation of the distal radius and ring sign (arrow).
108. Gaucher’s Disease:
Gaucher disease is an inherited disorder that affects many of the body's organs
and tissues. The signs and symptoms of this condition vary widely among affected
individuals. Researchers have described several types of Gaucher disease based on
their characteristic features.
Type 1 Gaucher disease is the most common form of this condition. Type 1 is also
called non-neuronopathic Gaucher disease because the brain and spinal cord (the
central nervous system) are usually not affected. The features of this condition
range from mild to severe and may appear anytime from childhood to adulthood.
Major signs and symptoms include enlargement of the liver and spleen
(hepatosplenomegaly), a low number of red blood cells (anemia), easy bruising
caused by a decrease in blood platelets (thrombocytopenia), lung disease, and
bone abnormalities such as bone pain, fractures, and arthritis.
Types 2 and 3 Gaucher disease are known as neuronopathic forms of the disorder
because they are characterized by problems that affect the central nervous
system. In addition to the signs and symptoms described above, these conditions
can cause abnormal eye movements, seizures, and brain damage. Type 2 Gaucher
disease usually causes life-threatening medical problems beginning in infancy.
Type 3 Gaucher disease also affects the nervous system, but it tends to worsen
more slowly than type 2.
109. The most severe type of Gaucher disease is called the perinatal
lethal form. This condition causes severe or life-threatening
complications starting before birth or in infancy. Features of
the perinatal lethal form can include extensive swelling caused
by fluid accumulation before birth (hydrops fetalis); dry, scaly
skin (ichthyosis) or other skin abnormalities;
hepatosplenomegaly; distinctive facial features; and serious
neurological problems. As its name indicates, most infants with
the perinatal lethal form of Gaucher disease survive for only a
few days after birth.
Another form of Gaucher disease is known as the
cardiovascular type because it primarily affects the heart,
causing the heart valves to harden (calcify). People with the
cardiovascular form of Gaucher disease may also have eye
abnormalities, bone disease, and mild enlargement of the
spleen (splenomegaly).
110. Gaucher disease, X-ray of lower thigh lateral view showing
Erlenmeyer flask deformity in distal femora. Note diffuse osteopenia
111. The radiographs show bilaterally symmetrical relative constriction of diaphysis and
flaring of metaphysis(Erleynmayer flask Deformity) with metaphyseal sclerotic bands.
112. T1 and T2 weighted coronal images of the femora. There is focal
heterogenous signal change in the left femur due to marrow infiltration.
113. Coronal T1-weighted MR image of the femora. There is diffuse, heterogenous hypointensity throughout both femora
and visualised tibiae in keeping with Gaucher infiltration. Note also the bilateral Erlenmeyer flask deformity.
114. T1 weighted coronal MRI. The serpiginous abnormalities seen in the distal femora represent areas of bone infarction.
115. Pre-treatment (left) and post-treatment (right) images of a 27 year old GD patient. There has been
a dramatic improvement in the appearance of low T1-weighted signal abnormality in the femora.
116. T1 and T2 weighted sagittal images of the lumbar spine in a patient with GD.
There is diffuse marrow infiltration and several collapsed vertebrae.
117. Images of the spleen of a GD patient taken pre- (left) and post (right) treatment with ERT.
MRI is an accurate way of measuring changes in volume of the spleen and liver.
118. 99mTc-sulfur colloid bone marrow scan of a 6 year old. There is marked splenomegaly with
abnormal increased uptake in the liver and spleen. There is generalized reduction in marrow
activity with areas of total absence of activity, for example, in the mid shaft of the right femur.
119. Quantitative Chemical Shift Imaging (QCSI) is used to accurately
quantify fat content in bone marrow of GD patients.