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SKELETAL DISORDERS OF METABOLIC AND ENDOCRINE ORIGIN DR. NAVNI GARGDNB RESIDENT, MEDANTA –THE MEDICITY
MATURE BONE
Lies within the medullary canal
Meshwork of primary longitudinal and secondary transverse trebaculae
Normally in ends of long bones and axial skeleton
Consists of haversian system : haversian canal surrounded by bony lamellae with volkman’s canal connecting them
TREBACULAR/ CANCELLOUS/ SPONGY CORTICAL
PARTS OF LONG BONE
GROWTH PLATE / PHYSIS Located at end of long bones between epiphysis
and metaphysis Site at which proliferation and orderly maturation of
cartilage cells occur Functionally part of shaft of long boneFour zones Resting/ germinal zone Proliferating zone Hypertrophic zone : zone of maturation,
degeneration and provisional calcification Zone of primary and secondary spongiosa
GROWTH PLATE Proliferating : cartilage
cells multiply Hypertrophic : marks
the end of lucent growth plate and beginning of calcified metaphysis
Spongiosa : calcified cartilage column, produce bone via enchondral calcification
BONE FORMATION
CLASSIFICATION Defect in osteoid formation : scurvy Defect in mineralization : rickets/
osteomalacia Disorder with increased bone resorption :
hyperparathyroidism Disorder with decreased bone mass :
osteoporosis Miscellaneous : fluorosis, heavy metal
poisoning, hypervitaminosis
CAUSES OF RICKETS AND OSTEOMALACIA
NUTRITIONAL RICKETS
PATHOLOGY Characteristic changes of rickets are identified
in the growth plate prior to closure Disorganisation of growth plate and adjacent
metaphysis Zone of maturation affected with disorganised
increase in number of cartilageneous cells : increase in length and width of growth plate
Zone of provisional calcification shows deficient mineralisation : Increased uncalcified osteoid and decrease in calcified osteoid
CLINICAL FEATURES First 6 months : tetanic convulsions Irritability, weakness Delayed development Small stature Bony deformities and pain Rachtic rosary Swelling of wrist and costocartilage
RADIOLOGICAL FEATURES MC and non specific finding : osteopenia Changes seen at open growth plate Especially visible at fast growing growth
plates like costochondral junction of the middle ribs, distal femur, proximal humerus, both ends of tibia, distal ulna and radius
Earliest sign : distal ends of radius and ulna. Ulnar growth plate grows more rapidly so manifestations are seen earlier in ulnar growth plate
WIDENING OF GROWTH PLATE Earliest and specific radiological change Due to increase in cartilageneous cell
mass
METAPHYSEAL FRAYING Irregular
metaphyseal margins occuring due to fraying and disorganisation of spongy bone in the metaphyseal region
METAPHYSEAL CUPPING AND WIDENING
Protrusion of bulky mass of cartilageneous cells in the zone of hypertrophy into the poorly mineralized metaphysis
Cupping is common in both ends of fibula and distal end of ulna and tibia
Not seen in bones of elbow
EPIPHYSEAL ABNORMALITIES Osteopenia Irregural and indistinct borders Delayed appearance of ossification
centres
SHAFT ABNORMALITIES Rarefaction of shaft due to loss of
mineral content Cortex becomes thin with a coarse
texture
SKELETAL DEFORMITIES Skull : Craniotabes Long bones : bowing deformities Ribs : rachitic rosary Spine : scoliosis and vertebral end plate
deformities (when weight bearing becomes prominent)
Pelvis : triradiate configuration
CRANIOTABES Excess osteoid
deposition in frontal and parietal regions with posterior flattening of skull due to supine posture of infant
Squared configuration of skull
Demineralisation of skull
BOWING OF LONG BONES Result of
displacement of growth centres owing to asymmetrical musculotendinous pull on the weakened growth plate
RACHITIC ROSARY Bulbous
enlargement of costochondral junction especially middle ribs
May indent pleural surface or thymic shadow
TRIRADIATE PELVIS Protrusion of hip
and spine into the soft pelvis with protrussio acetabuli
SIGNS OF HEALING RICKETS Seen within 2-3 weeks of adequate therapy Total calcification is usually complete in 2
monthsSigns : Reappearance of dense zone of provisional
calcification : first evidence Increase in cupping of healing metaphysis Recalcifiaction of subperiosteal osteoid
resulting in thick cortex surrounding the shaft Sharply defined ossification centres
REAPPEARANCE OF DENSE ZONE OF PROVISIONAL CALCIFICATION
Seen as a transverse line of increased density which appears beyond the visible end of shaft with a metaphysis interposed between two radiolucent areas
Complete healing and restoration of normal structure is the rule in rickets even if severe changes are present during the active stage !!!!
HEREDITARY VITAMIN D DEPENDANT RICKETS
1 alpha hydroxylase deficiency
Dec levels of 1,25 dihydroxy D 3
Presents within 3 months Convulsions and muscle
weakness, severe rachitic bone changes, pathologic fractures
Rx : 1,25- dihydroxy D3
End organ resistance to 1,25-dihydroxy D3
Elevated levels of 1,25 dihydroxy D3
Severe rickets,growth retardation, dental changes, alopecia
Rx : Calcium supplements
TYPE 1 (Psuedo vitamin D deficiency )
TYPE 2 (Calcitriol resistant rickets )
X LINKED HYPOPHOSPHATEMIA
Familial Vitamin D resistant/ refractory rickets MC form of renal tubular rickets and osteomalacia X linked dominant Rickets develops between 12-18 months of age Lifelong hypophosphatemia due to impaired
reabsorption of phosphate from proximal tubules Also impaired conversion of 25 hydroxy D3 into
1,25 dihydroxy D3 Low serum phosphate, normal serum calcium,
normal PTH
RADIOLOGIC FEATURES Bowing of legs Coarsening of trebacular
pattern with increasing age Generalized
increase/normal bone density especially axial skeleton
Calcification and ossification in paravertebral ligaments, ligamentum flavum, iliolumbar and sacroiliac ligaments
Osteoarthritis in ankle, knee, wrist, sacroiliac joints
ONCOGENIC OSTEOMALACIA Seen in adults with some vascular
neoplasms like hemangiopericytoma Tumors produce phosphatonin which
inhibits absorption of phosphate in proximal tubule resulting in hypophosphatemia
Advanced rachitic changes may be present
Refractory to vitamin D therapy Respond to tumor removal
DRUG INDUCED RICKETS Due to high doses of ifosfamide Nephrotoxic Metabolites cause tubular
damage Results in fanconi syndrome and
hypophosphatemic rickets
METAPHYSEAL CHONDRODYSPLASIA
Generalised symmetric disturbance of enchondral bone formation primarily at metaphysis
Seen in childhood : short stature, bowing of long bones
Normal serum calcium, phosphorus, ALP levels Widening of growth plate with multiple bony
projections growing from metaphysis into growth plate Metaphysis is well mineralised and shows increased
density with absence of loosers zone Spontaneous improvement, no response to vitamin D
therapy
HYPOPHOSPHATASIA
Defective skeletal mineralisation with normal serum calcium and phosphorus, low levels of alkaline phosphatase
Increased amount of phosphoethanolamine amino acid in blood and urine
Usually presents in infancy and childhood
Neonatal death may occur in severe disease
RADIOLOGICAL FEATURES Growth plate changes
similar to rickets with multiple radiolucent extensions into the metaphysis (uncalcified bone matrix)
Coarse trebacular pattern
Bowing deformity, fractures
Wormian bones, craniosynostosis
ATYPICAL AXIAL OSTEOMALACIA
Axial skeletal involvement with sparing of appendicular skeleton
Dense coarse trebacular pattern : most marked in cervical region , may be seen in Lumbar spine, pelvis or ribs
Normal serum calcium, phorphorus, ALP No response to vitamin D therapy
OSTEOMALACIA
PATHOLOGY Abnormalities are seen in mature areas
of trebacular and cortical bone Defective mineralisation of cortical and
spongy bone with Increase in unmineralised osteoid
C/F : fatigue, malaise , bone pain , proximal muscle weakness
RADIOLOGICAL FEATURES Osteopenia : Uniform involving all the bones Coarse indistinct trebacular pattern Thin cortex of long bones Pseudofractures Bone deformities : medial acetabular
migration (protrussio acetabuli ), triradiate pelvis, bowing of legs
Spine : kyphoscoliosis , increased endplate concavity
Pseudofractures / umbauzonen/loosers zone/milkman’s fracture
More specific but less common manifestation
Loosers zone : linear areas of undermineralised osteoid that occur in bilateral, symmetric distribution
Oriented at right angles to the cortex Occur due to vascular pulsation acting on
the softened bones May show mild-moderate sclerosis with
absence of callus formation
Site of increased stress resulting in fracture
Accelerated bone turnover
Inadequately mineralised osteoid
Radiolucent area
LOOSER’S ZONESites : Axillary margins of
scapula Superior and
inferior pubic rami Inner margin of
proximal femur Posterior margin of
proximal ulna Ribs
SPINE
Defective mineralisation
Overall decrease in number of bony trebaculae within all the bones enhancing the contrast of remaining trebaculae giving coarse mottled appearance
Decreased bone mass without any defect in mineralisation
Trebaculae are thin and sharp
OSTEOMALACIA OSTEOPOROSIS
HYPERPARATHYROIDISM
Occurs due to excessive production of PTH
Primary : due to excess production by abnormal gland like adenoma, hyperplasia , carcinoma
Secondary : abnormality in gland induced by sustained hypocalcemic stimulus like CRF, malabsorption states
Tertiary : due to long standing secondary HPT who develop autonomous parathyroid function
ACTIONS OF PTH
CALCIUM METABOLISM
RADIOLOGICAL FEATURES Bone resorption Brown tumors Joint disorders Osteosclerosis Renal osteodystrophy
BONE RESORPTION Hallmark of hyperPTH Due to increased osteoclastic activity Can be subperiosteal, intracortical,
endosteal , subchondral and trabecular Cortical bone is affected more than
cancellous bone Seen as poor definition of cortical
surfaces , increased cortical striations (tunneling ), cortical thinning , distortion and blurring of trabecular bone
SUBPERIOSTEAL RESORPTION
Pathognomic of HPT Earliest site : radial
aspect of middle phalanges of middle and index fingers and terminal tufts of fingers
Others : medial aspect of proximal end of tibia, humerus and femur, superior and inferior margins of ribs, lamina dura
LOSS OF LAMINA DURA Seen in dental sepsis, pagets disease,
fibrous dysplasia, osteomalacia also
INTRACORTICAL BONE RESORPTION
Osteoclasts tunnel through volkman’s and haversian canals causing tiny linear striations within the cortex parallel to long axis of bones
Tubular bones of hands and feet esp cortex of second metacarpal
Almost always associated with subperiosteal resorption
ENDOSTEAL BONE RESORPTION Leads to cortical thinning, scalloping and
irregularity of the endosteal surface esp bones of hand
Mostly occurs in conjuction with subperiosteal and intracortical resorption
SUBCHONDRAL BONE RESORPTION
Common manifestation of hyperPTH Seen in joints of axial skeleton,
sacroiliac, sternoclavicular , acromioclavicular , pubic symphysis, discovertebral junctions
Surface irregularity with increased joint space
Most severe in distal ends of clavicle
SUBPHYSEAL BONE RESORPTION Seen in children with primary or
secondary hyperHPT Irregular radiolucent areas in metaphysis
adjacent to growth plate
SUBLIGAMENTOUS AND SUBTENDINOUS BONE RESORPTION
Occurs at sites of tendon and ligament attachment to bone
Involves femoral trochanter, ischial and humeral tuberosities, elbow , inferior surface of calcaneum, inferior aspect of distal end of clavicle
TREBACULAR BONE RESORPTION Occurs throughout skeleton in advanced
stage of disease Osteoclasts dissect through the centre of
trabecula giving a stippled, mottled, granular appearance of skull ( SALT AND PEPPER SKULL)
Definition of inner and outer table is lost
SALT AND PEPPER SKULL
BROWN TUMORS Osteitis fibrosa cystica Cystic lesions within the bone due to
extensive bone resorption May cause swelling, pathological fracture
or pain Represent hemorrage and deposition of
breakdown products of hemoglobin Risk of pathological fracture is more
when brown tumor involves more than two thirds of the cortex of long bone especially in weight bearing areas
Multiple Iytic, expansile ,cystic lesion
Eccentric or cortical location
Sites : mandible, clavicle, ribs, pelvis and tubular bones
JOINT DISORDERS Erosive arthropathy of hands, wrists and
shoulders Almost always associated with typical
subperiosteal resorption of phalanges and occur on ulnar aspect of metacarpal heads
Chondrocalcinosis or calcification of hyaline/fibrocartilage of knee, pubic symphysis or wrist due to calcium pyrophosphate dihydrate deposition
OSTEOSCLEROSIS Increased bone density due to
stimulation of osteoblastic activity by PTH in addition of osteoclastic activity
Sec HPT : diffuse increase in bone density
Pri HPT : localized / patchy sclerosis Focal bone sclerosis seen in metaphyseal
regions of long bones, skull , vertebral end plates
Skeletal features Less florid skeletal
features Sclerosis rare Brown tumors and
chondrocalcinosis more common
Soft tissue and vasc calcification less common
Skeletal features with changes of renal osteodystrophy
More florid Sclerosis common Brown tumors and
chondrocalcinosis less common
Soft tissue and vasc calcification more common
PRIMARY HYPERPTH SECONDARY HYPERPTH
DIALYSIS ASSOCIATED ARTHROPATHY
Axial and appendicular skeleton destructive arthropathy due to long term dialysis
Chronic, progressive ,symmetric polyarthropathy involving large and small peripheral joints
Periarticular cysts , erosions , loss of joint space , loss of articular surface, osteopenia
SPINE DRSA usually after 3-5 years of dialysis,
cervical spine involved MC . Narrowing of disc height, subchondral
cysts, endplate erosions, collapse, erosion of contiguous vertebral bodies, facet erosion , spondylolisthesis, peridiscal calcification.
Calcification in subcutaneous regions, vascular, muscular , visceral organ .
RENAL OSTEODYSTROPHY
Bony changes seen in patients with chronic renal insufficiency
Children : structural abnormalities of urinary tract
Adults : chronic glomerulonephritis
RADIOLOGIC FEATURESSec hyperparathyroidism Bone resorption (subperiosteal,
intracortical , endosteal , subligamentous) Brown tumors Soft tissue and vascular calcification Osteosclerosis ( focal / diffuse ): rugger
jersey spine, pelvis , ribs , clavicles Osteopenia : end result of osteomalacia,
bone resorption, osteoporosis
RENAL OSTEODYSTROPHY
Deposition of bone in subchondral areas of vertebral bodies
Radiodense bands across superior and inferior vertebral margins
Rugger jersey spine
CALVARIAL THICKENING
HYPOPARATHYROIDISM
CAUSES OF HYPOPTH MCC : excision/ trauma to parathyroid
gland during thyroid surgery Idiopathic hypoparathyroidism due to
circulating antibodies to PTH , adrenal and thyroid glands
Radiation induced damage to the gland
Low serum calcium and PTH , high phosphate
RADIOLOGICAL FEATURES Focal or generalised bone sclerosis Pelvis, proximal femur , vertebral bodies Calvarial thickening Hypoplastic Dentition Band like areas of increased radiodensity in
metaphysis of long bones Calcifiction and ossification of anterior
longitudinal ligament and spinal osteophytes Calcification in basal ganglia, cerebrum,
cerebellum
Mineralization of iliolumbar ligament (pink arrow), broad ossification at the lateral margin of acetabulum (white arrow), osseous proliferation and irregular bony excrescences above the acetabulum (arrowhead), and lesser and greater trochanters and ischial tuberosities (open arrows)
Capsular calcification of the hip joint (black arrow) and internal fixator for the right femoral shaft fracture.
Bilateral basal ganglia calcification
PSEUDOHYPOPARATHYROIDISM
Autosomal dominant Due to end organ resistance to
parathyroid hormone Due to defect in adenyl cyclase cyclic
AMP system in renal tubules and bones Second decade, F>M Short , obese , mentally retarded,
brachydactyly Low calcium, high PTH and phosphate
RADIOLOGICAL FEATURES Shortening of fourth
metacarpal Soft tissue calcification
and ossification, basal ganglia and calcification
Calvarial thickening Short metatarsals and
phalanges Premature closure of
epiphysis Exostoses projecting at
right angles to the bone Features of hypoPTH
Not seen Short first and fourth metacarpal
Exostosis perpendicular surface of bone
HYPOPARATHYROIDISM PSEUDOHYPOPARATHYROIDISM
PSUEDOPSEUDOHYPOPARATHYROIDISM
Result of incomplete genetic manifestation of PHP
Caused by end organ resistance to PTH Pts with PPHP have normal calcium Radiological features like PHP except
higher rate of short metacarpals in PPHP and short distal phalanges in PHP
HYPERCORTISOLISM
CAUSE Tumor of adrenal gland Ectopic ACTH production Iatrogenic Basophil pituitary adenoma
Inhibiton of bone formation Stimulation of bone resorption Decrease in intestinal absorption of
calcium Decrease in synthesis of collagen
Osteonecrosis, osteoporosis, muscle wasting
RADIOLOGICAL FINDINGS Generalized loss of bone density : spine, pelvis, ribs,
cranial vault (trebacular bone > cortical bone) Accentuation of primary trebaculae, with central
endplate depressions in the vertebral bodies (biconcave fish like appearance )
Increased radiodensity of superior and inferior margins of compressed / collapsed vertebrae (d/t exuberant callus formation )
Exuberant callus at fracture sites in long bones and ribs
Local regions of osteonecrosis esp after exogeneous steroids ( AVN at femoral and humeral heads)
Skeletally immature child Suppresses growth : short child Osteoporosis , truncal obesity , delayed
bone age Osteonecrosis at growing epiphysis may
lead to abnormal development at ends of long bones
Early development of osteoarthropathy
HYPOPITUITARISM
Delay in skeletal maturation : delay in appearance and closure of epiphysis
Retarded skeletal growth Overall loss of bone density
HYPOTHYROIDISM
Thyroid neoplasm Thyroiditis Thyroid ablation Disturbance in
iodine metabolism
Def of TSHPRIMARY SECONDARY
Infant : cretinism Child : juvenile myxedema Adult : myxedema
CONGENITAL HYPOTHYROIDISMXRAY WRIST AND XRAY KNEE Delay in skeletal maturation with bone age lagging
behind chronological age : short stature and late appearance of epiphyseal ossification centres
Normally , distal femoral epiphysis is ossified at 36 wks and proximal tibial epiphysis at 38 wks : dec size/ absence indicates hypothyroidism
Deformed , irregularly shaped epiphysis (EPIPHYSEAL DYSGENESIS ): bilateral and symmetrical
Delayed closure of epiphyseal plates
Skull : sutures may remain open and show wormian bones, small sella in young or large, rounded in old children
PNS are underdeveloped Pelvis : narrow with coxa vara deformity ,
inc incidence of SCFE Spine : bullet shaped VB , kyphosis
ADULT HYPOTHYROIDISM Mild skeletal manifestations Generalized osteoporosis
HYPERTHYROIDISM
Accelerated skeletal maturation therefore bone age ahead of chronological age
Osteoporosis with VB fracture and kyphosis
CHILD ADULT
RADIOLOGICAL FINDINGS Osteoporosis : spine, pelvis, skull, hands and feet Progression of thyrotoxic osteoporosis is faster than
post menopausal osteoporosis but same radiologically
DL vertebra more affected : Biconcave VB , wedge deformities , kyphosis, fractures
Tubular bones of hands, feet : cortical tunneling and striations due to inc osteoblastic and osteoclastic activity
Thyroid acropachy in treated pts : exophthalmos, soft tissue swelling of fingers and toes, pretibial myxedema or clubbing
Dense , solid, periosteal new bone formation with feathery margins
Asymmetric periosteitis : most prominent along the radial margin of metacarpals and phalanges in the diaphyseal region
Hands and feet Feathery contour
Long bones Absent
THYROID ACROPACHY HYPERTROPHIC OSTEOARTHROPATHY
TURNERS SYNDROME
Skeletal maturation is usually normal till 15 years of age following which delayed epiphyseal closure occurs esp apophysis of iliac crest
Depression or slanting of the medial tibial plateau with concomitant overgrowth of medial condyle of femur
Short fourth and fifth metacarpal Narrow ribs Small sella Android pelvis Hypertelorism
ACROMEGALY
Reactivation of enchondral bone formation
Stimulates periosteal bone formation Connective tissue proliferation
CLINICAL FEATURES 3-4 decade Coarse facial features Thick skin Dental occlusion Deepening of voice Prominent tongue Broad hands and feet Organomegaly
DEFINITIVE DIAGNOSIS 24 hours serum GH levels GH secretion not suppressed by oral
glucose Serum level of insulin like growth factors
RADIOLOGICAL FINDINGSSKULL
Cranial vault thickening Prominence of supraorbital ridges and zygomatic
arches Prominence of ext occipital protruberance Enlargement of sella Prominence and enlargement of maxillary and
frontal sinuses Excessive pneumatisation of mastoid Enlargement and elongation of mandible with
widening of mandibular angle
HANDS AND WRIST AND FEET Soft tissue thickening of fingers Thickening and squaring of phalanges and
metacarpals Overconstriction of shafts of phalanges Abn wide articular surfaces : MCP, MTP, IP Bony excrescences at site of tendon and ligament
attachment to bone Prominence of ungal tufts ( spade like ) Keel shaped deformity : resorption of cortex along
plantar aspect
INDICES Increased phalangeal soft tissue thickness at
prox mid phalanges > 27 mm (men) and > 26 mm (women)
Widening of second MCP joint > 2.5 mm in men and women
Bone excrescences and marginal spurs Inc width of phalages : spade like Large sesamoid index > 40 mm(M) and >
32mm (F) Inc interstyloid distance
HEAL PAD THICKNESS Shortest distance between calcaneum
and plantar surface of skin > 21.5 mm (f) and >23 mm (m) :
suggestive >23 mm (f) and > 25 mm (m) :
diagnostic
MALE FEMALE
HEEL PAD THICKNESS > 23 > 21.5
SESAMOID INDEX >40 >32
TUFTAL WIDTH >12 >10
PHALANGEAL SOFT TISSUE >27 >26
JOINT SPACE >2.5 >2.5
VERTEBRAL COLUMN Elongation and widening of vertebral
bodies Increase in vertebral height Ant and lat osteophytes Inc height of IVD Scalloping of post margins of VB Inc thorasic kyphosis Exagerrated lumbar lordosis
Enlarged thorax due to elongation of ribs and prominence of costochondral junction
Pelvis : enlargement and beaking of symphysis pubis
Feet : soft tissue enlargement , prominence of tufts and base of terminal phalanges, bone proliferation at sites of tendon and ligament attachment like undersurface of calcaneum
Articular abnormalities : knee, hips, glenohumeral joints. Widening of articular space seen at MCP, MTP and IP joints
ACROMEGALIC ARTHROPATHY
Hypertrophy causing Fissuring Ulceration Denudation
(Degenerative arthropathy , changes of OA )
Hypertrophy Brisk
regeneration : chronic > thickened cartilage > inc joint space > enlarged bones > hypertrophy of periarticular soft ts.
HYALINE CARTILAGE FIBROCARTILAGE
FIBROCARTILAGE HYPERTROPHY Calcification and ossification > calcinosis
+ osteophytes > at atypical sites like glenohumeral and elbow joint
Presence of beaklike osteophytes at inferior part of head of humerus , lateral aspect of acetabulum , medial part femoral head , sup margin pubic symphysis , radial head , tibia
GIGANTISM
Extreme height with normal body proportions
SCURVY
Due to long term vitamin c deficiency Infantile : due to pasteurised or boiled
milk formula 6 months – 2 years C/F : progressive irritability with tender
edematous limbs, subcutaneous / mucous membrane hemorrages, anaemia, bleeding gums, malena, bulging at costochondral junction
PATHOLOGY Vitamin C necessary for Endothelial
lining : deficiency causes increased vascular fragility
Decreased osteoblastic activity and cartilage proliferation resulting in decreased formation of bony matrix
Normal mineralisation Osteoporosis
WHITE LINE OF FRENKEL White line in the zone
of provisional calcification at the growing metaphysis
Cartilage proliferation decreased with normal mineralisation resulting in widened and dense zone of provisional calcification
TRUMMERFELD ZONE (SCORBUTIC ZONE)
Transverse radiolucent band adjacent to zone of provisonal calcification due to suppressed osteoblastic activity with normal mineralisation
Trabecular bone mass is decreased in zone of primary and secondary spongiosa.
WIMBERGER SIGN Epiphysis is small
sharply marginated by sclerotic rim with central portion more radiolucent.
Due to decrease cartilage proliferation and unimpaired mineralization (sclerosis)
CORNER (ANGLE) SIGN Irregularity of the
metaphyseal margins secondary to infractions of the epiphyseal-metaphyseal junction
PELKAN’S SPUR Zone of
provisional calcification extends beyond the margins of the metaphysis resulting in periosteal elevation and marginal spur formation
SUBPERIOSTEAL HEMORRAGES
Due to increased capillary permeability
Seen in ends of long bones(femur,tibia, humerus)
May cause periosteal elevation and new bone formation
On vitamin C therapy, all changes are reversible though single growth arrest line may remain in metaphysis as residual frenkel’s line.
FLUOROSIS
ETIOLOGY Chronic ingestion of flouride in excess of
8 ppm in drinking water Industrial expose to fluorine
compounds for many years In laboratory personnel due to
inhalation of fluorine vapors Agricultural fluoride contamination Habitual drinking of wine containg
fluorine i.e. wine fluorosis
PATHOLOGY Generalized increase in bone density due to
osteoclastic response to fluorine
Excess fluorine Osteoclastic activity increases, Disturbed normal collagen synthesis
Fluoride have strong affinity for bone salts replacing hydroxyl ion; Hydroxipatite converted into fluoropatite which is more resistant to dissolution
CLINCAL FEATURES Initially asymptomatic Rare in children because it takes 12 or
more years after exposure to develop changes
Polydipsia Anemia Mottling of enamel of teeth Crippling stiffness and pain Pathological fractures
RADIOLOGIC FEATURES Thickening of the
cortex of affected bones
Ribs : Inferior margin may show irregularity/fringed appearance (rose thorn appearance )
Osteosclerosis most marked in
spine, pelvis, ribs Skull and tubular
bones are spared Calvarium :
sclerosis of base of skull and posterior clenoid
Ossification and calcification of ligaments of sacrospinous, sacrotuberous
Ossification of interosseus membrane
Vertebral Osteophytes Paraspinal and
intraspinal ligament ossification
OSSIFICATION OF INTERROSEUS MEMBRANE
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