skeletal dysplasia : radiodiagnosis

SKELETAL DYSPLASIA

Dr. Kunaal Jain

▪ ACHONDROPLASIA

▪ CLEIDOCRANIAL DYSPLASIA

▪ CHONDRODYSPLASIA PUNCTATA

▪ HOLT-ORAM SYNDROME

▪ INFANTILE CORTICAL HYPEROSTOSIS

▪ MARFAN’S SYNDROME

▪ NAIL-PATELLA SYNDROME

▪ MELORHEOSTOSIS

▪ MASSIVE OSTEOLYSIS OF GORHAM

▪ MPS-I: HURLER’S SYNDROME

▪ MPS-IV: MORQUIO’S SYNDROME

▪ OSTEOGENESIS IMPERFECTA

▪ OSTEOPETROSIS

▪ OSTEOPOIKILOSIS

▪ PYKNODYSOSTOSIS

▪ THANATOPHORIC DWARFISM

▪ Dwarfing dysplasia's are abnormalities of cartilage and bone that result in short stature, defined as 3 standard deviations below the mean for age, race, and sex.

▪ Rhizomelia : shortening at the "root," femur, and humerus. Eg. Achondroplasia.

▪ Mesomelia : shortening in the "middle," tibia/fibula and radius/ulna. Eg. Chondroectodermal dysplasia.

▪ Acromelia : shortening at the "end," hands, and feet.

▪ Micromelia : refers to shortening of the entire limb. Eg. Achondrogenesis.

ACHONDROPLASIA

▪ Rhizomelic dwarfism with normal trunk, large head, and midface hypoplasia.

▪ Most common nonlethal skeletal dysplasia with male predominance.

▪ Autosomal dominant disturbance in epiphyseal chondroblastic growth and maturation.

PRENATAL ULTRASOUND

Normal scan in 1st trimester

Long bone shortening evident after 22 weeks

Thoracolumbar kyphosis

Megalencephaly

Depressed nasal bridge

Normal ossification

No fractures, angular deformities of long bones

Polyhydramnios

RADIOGRAPHIC FEATURES

▪ Craniofacial

Enlarged head with frontal bossing

Hydrocephalus

Midface hypoplasia

▪ Pelvis and extremities

Narrow sacroiliac notches

Shallow acetabular angle

Trident hand

Genu varum

▪ Spine and pelvis

Narrowed interpediculate distance distal L spine

Bullet-shaped vertebra at thoracolumbar junction

Posterior vertebral body scalloping

Congenital canal stenosis 2° to short pedicles

Thoracolumbar gibbus in infancy

CLEIDOCRANIAL DYSPLASIA

▪ Cleidocranial dysostosis, Marie-Sainton disease.

▪ Autosomal dominant.

▪ Non-dwarfing dyaplasia.

▪ Characterized by faulty ossification of the intramembranous and enchondral bones.

RADIOGRAPHIC FEATURES

▪ Clavicles : absent or hypoplastic

▪ Hypoplastic central superior and inferior pubic rami

▪ Skull: Wormian bones, wide sutures, premature closurecoronal suture, persistent metopic suture, thin calvaria, persistent fontanelle.

▪ Coxa vara

▪ Hypoplastic glenoid

▪ Narrow chest

▪ • Face: Hypertelorism, frontal bossing, protruding jaw with malocclusion, high arched or cleft palate, dental anomalies

▪ • Hand: Short middle and distal phalanges, pointed distal phalanges; accessory metacarpal ossification centers, elongated 2nd metacarpal.

▪ Short middle phalanx, especially 2 and 5 digits

▪ Elongated 2nd metacarpal.

▪ Coned epiphyses

THANATOPHORIC DWARFISM

▪ Death-bearing dwarf.

▪ Most common lethal skeletal dysplasia.

Type I: "Telephone receiver" femurs

Type II: "Cloverleaf" skull (Kleeblattschädel)

PRENATAL ULTRASOUND

▪ Can be diagnosed as early as 14 weeks

▪ Increased nuchal translucency

▪ Severe micromelia

▪ Platyspondyly

▪ Severe polyhydramnios 2nd trimester

RADIOGRAPHIC FEATURES

▪ Severe rhizomelic limb shortening & bowing.

▪ Severe platyspondyly, increased disc space height.

▪ Long chest with short horizontal ribs.

▪ "Cloverleaf" skull.

▪ Enlarged head with frontal bossing.

▪ Narrow sacroiliac notch with flat acetabular roof and small squared iliac wings.

▪ Outwardly bowed ("telephone receiver") femurs.

HOLT-ORAM SYNDROME

▪ Heart-hand syndrome, Cardio-limb syndrome, and Cardiomelic syndrome.

▪ Cardiac deformities ( ASD/VSD) and anomalies of the arms and hands.

▪ Uncommon autosomal dominant dysplasia.

▪ Do not involve the lower extremities.

RADIOGRAPHIC FEATURES

▪ Hypoplasia or complete absence of the radius.

▪ Hypoplastic humeri, clavicles and scapulae, and Sprengel’s deformity.

▪ An extra phalanx in the first digit is frequent (triphalangeal thumb).

▪ Extra carpals are common, and carpal fusions.

▪ The middle phalanges of the fifth fingers are short with association of Clinodactyly.

INFANTILE CORTICAL HYPEROSTOSIS

▪ Caffey Disease.

▪ Autosomal dominant transmission reported

▪ •Acute: Inflammation in periosteum ± soft tissues.

▪ ○ Periosteal new bone ± cortical resorption.

▪ • Subacute stage: Periostitis ossifies, incorporated into cortical bone.

RADIOGRAPHIC FEATURES

▪ Mandible involved > 80% cases.

▪ Favours ribs, clavicles, scapula, skull, ilium.

▪ Ulna : most involved of the long bones.

▪ Diaphysis, ± metaphysis, spares epiphyses.

▪ As periostitis is incorporated into cortical bone → medullary cavity widening, bowing.

▪ Exceptions of the vertebrae, phalanges and round bones (carpals and tarsals).

NAIL-PATELLA SYNDROME

▪ Fong Disease / Hereditary osteo-onychodysplasia(HOOD) disease / Iliac horn syndrome / Turner-Kiesersyndrome.

▪ Autosomal dominant.

▪ Hypoplasia or splitting of the nails seen on the thumb and index finger.

▪ Associated with renal disease, glaucoma, Lester iris (hyperpigmentation of pupillary margin of iris), pterygium, Irritable bowel syndrome.

RADIOGRAPHIC FEATURES

▪ Iliac horns.

▪ Absent/hypoplastic patella, flattened knee, hypoplastic lateral femoral condyle.

▪ Absent/hypoplastic radial head, capitellum and lateral condyle.

▪ Hypoplastic changes shoulder, hip.

▪ Talipes equinovarus and other foot deformities

CHONDRODYSPLASIA PUNCTATA

▪ Stippled epiphyses / Dysplasia epiphysealis punctata / Chondrodystrophia fetalis calcificans / Chondrodystrophia calcificans congenita.

▪ Epiphyseal dysplasia characterized punctate or stippled calcification of multiple epiphyseal centersduring the 1st year of life.

▪ An autosomal dominant form (Conradi-Hunermannsyndrome).

▪ Lethal Recessive Type.

RADIOGRAPHIC FEATURES

A) Conradi-Hunermann Syndrome

Stippling at the ends of long bones and short tubular bones.

Metaphyses and diaphyses are normal.

B) Lethal Recessive Type

▪ Epiphyseal stippling is noted primarily in the hips, shoulders, knees, and wrists.

▪ Metaphyses are often flared, and the long bones are bowed.

MARFAN’S SYNDROME

▪ Arachnodactyly / Dolichostenomelia.

▪ Autosomal dominant entity consisting of long, slender tubular bones, ocular abnormalities, and aortic aneurysm.

▪ Extremities are markedly elongated, with sparse soft tissue, owing to muscular hypoplasia and a scarcity of subcutaneous fat.

RADIOGRAPHIC FEATURES

▪ Disproportionate limb lengthening : hands and feet.

▪ Ligamentous laxity : Pes planus, hallux valgus, hammertoes.

▪ Joint dislocations (patella, hip, mandible, clavicle, digit.

▪ Normal bone density.

▪ Scoliosis, spondylolysis with spondylolisthesis

▪ Posterior vertebral body scalloping with dural ectasia

▪ Chest: Pectus excavatum or carinatum.

SKELETAL DYSPLASIA II

Dr. Kunaal Jain

MASSIVE OSTEOLYSIS OF GORHAM

▪ Hemangiomatosis, massive osteolysis, disappearing bone disease, vanishing bone disease, phantom bone disease and Gorham-Stout syndrome.

▪ Most commonly affected regions are the long bones, pelvis, thorax, and spine.

▪ Involved bone is soft and spongy with eroded cortices and is replaced by angiomatous tissue with unusually wide capillary-like vessels.

RADIOGRAPHIC FEATURES

▪ Intramedullary or subcortical lucent foci may be the earliest manifestation resembling patchy osteoporosis.

▪ Progresses to profound osteolysis with resorption of affected bone and lack of compensatory osteoblastic activity or periosteal reaction.

▪ Affected soft tissues become atrophied and demonstrate calcification within thrombi ( phleboliths).

▪ DD: Metastatic neuroblastoma, histiocytosis X.

MUCOPOLYSACCHARIDOSES

▪ Inherited metabolic disorders that result in widespread skeletal, visceral, and mental abnormalities.

▪ MPS-I (MPS-I-H): Hurler’s syndrome.

▪ MPS-I-S: Scheie’s syndrome.

▪ MPS-I-H-S: Hurler-Scheie syndrome.

▪ MPS-II: Hunter’s syndrome.

▪ MPS-III (subtypes A, B, C, and D): Sanfilippo’s syndrome.

▪ MPS-IV: (subtypes A and B) Morquio’s syndrome.

▪ MPS-VI: Maroteaux-Lamy syndrome.

▪ MPS-VII: Sly’s syndrome.

MPS-I: HURLER’S SYNDROME

▪ Lipochondrodystrophy, Gargoylism, Osteochondrodystrophy, and Dysostosis multiplex.

▪ Autosomal recessive disorder : leads to excessive lipoid accumulation in the central nervous system.

▪ Most severe form of MPS I :Mental retardation, deafness, dwarfism, hepatosplenomegaly, cardiomegaly, corneal clouding.

RADIOGRAPHIC FEATURES

▪ Macrocephaly, frontal bossing, calvarial thickening, and premature closure of the sagittal and lambdoid sutures.

▪ J-shaped sella.

▪ Atlanto-axial subluxation and thoracolumbar kyphosis.

▪ Ribs are overly wide, with tapered ends : paddle or spatulatedappearance.

▪ Coxa valga or vara.

▪ Varus deformity of the humerus is characteristic.

▪ Metacarpals and phalanges are short and wide : trident hand.

MPS-IV: MORQUIO’S SYNDROME

▪ Autosomal recessive disorder.

▪ An error in mucopolysaccharide metabolism leads to keratosulfaturia- diagnostic.

▪ Two forms (types A and B). Type B is the milder.

▪ Severe dwarfism, short spine with kyphoscoliosis, joint

▪ laxity, corneal clouding, deafness, normal intelligence.

RADIOGRAPHIC FEATURES

Platyspondyly with hypoplastic odontoid peg.

Atlantoaxial subluxation

Anterior central vertebral body beaking with round

vertebral bodies

Hypertelorism with dolichocephaly

Proximal point of index to little finger metacarpal

Flattened femoral epiphyses; risk of lateral subluxation

and dislocation

Coxa valga

Genu valgum

OSTEOPETROSIS

▪ Albers-Schönberg disease / Marble bone disease/ Osteosclerosis / Osteopetrosis generalisata, Osteosclerosis generalisata / Chalk bones.

▪ Lack of resorption of normal primitive osteochondroustissue.

▪ Undertubulation of metaphyses

▪ Bone within bone appearance

▪ Rugger jersey or sandwich vertebrae

▪ MRI: "Black bone"

▪ Bone scan: SuperScan

TYPES

▪ Infantile type (severe malignant form) : Autosomal recessive

▪ Adult types (benign heterogenous form) : Autosomal dominant

▪ Intermediate type: Autosomal recessive

▪ Sly disease (Carbonic anhydrase type II deficiency ) : Autosomal recessive

RADIOGRAPHIC FEATURES

▪ Skull base : Hyperostosis and sclerosis

▪ Bone within bone appearance : Most evident in spine, endobone in ilium

▪ □ As growth occurs, cortical bone is not resorbed and remains visible within larger (more adult) bone.

▪ Sclerotic bones : uniformly dense, smooth margins, loss of normal corticomedullary differentiation involving epiphysis, metaphysis, diaphysis.

▪ Most prominent in distal femur

▪ Cranial vault: diffuse thickening and sclerosis with loss of diploicspace.

OSTEOPOIKILOSIS

▪ Osteopathia condensans disseminata and Spotted bones.

▪ Autosomal dominant with male predominance.

▪ Sclerosing bony dysplasia characterised by multiple benign enostoses.

▪ Characterized by small round or ovoid radiopacities appearing in the juxta articular regions of bone.

▪ Associated with dermatofibrosis lenticularis disseminata, keloid formation, and scleroderma-like lesions.

▪ Multiple small radiopacities found scattered in epiphyseal and metaphyseal regions involving long tubular bones, carpals, tarsals , pelvis and scapula.

▪ Rarely, lesions are found in the skull, spine, ribs, and clavicles.

▪ Generally, the size ranges from 1 to 10 mm in diameter.

RADIOGRAPHIC FEATURES

PYKNODYSOSTOSIS

▪ Osteoporosis acro-osteolytica / Toulouse-Lautrec syndrome / Maroteaux-Lamy.

▪ Lysosomal storage disease resulting in dense bones.

▪ Autosomal recessive.

▪ Dense bones with short stature, acroosteolysis, decreased angle of mandible- diagnostic.

RADIOGRAPHIC FEATURES

▪ Osteosclerosis.

▪ • Acroosteolysis- resorption or band-like lucency in terminal tuft.

▪ Skull: Wormian bones ,thick skull base, thin cranial vault, persistent anterior fontanelle.

▪ Hypoplastic mandible.

▪ Hypoplastic/malformed clavicles.

▪ Fragility fractures- transverse in long bones.

▪ Spondylolysis.

OSTEOGENESIS IMPERFECTA

▪ Genetic defect in type I collagen resulting in multiple fractures with little trauma.

▪ Hallmark feature : osteoporosis and fragile bones that fracture easily, blue sclera, dental fragility, and hearing loss, ligamentous laxity and hypermobility of joints, short stature, and easy bruising.

▪ Types I and IV : imaged for routine fracture evaluation.

▪ Type II : imaged at birth; quickly lethal.

▪ Type III : Most severe type that survives into childhood.

PRENATAL ULTRASOUND

▪ Most cases identified at prenatal US are type II

▪ Presence of fractures differentiates from other short limbed dwarfs.

▪ Shortening with angulation, pseudarthroses.

▪ Crumpled appearance 2° to callus.

▪ Osteopenia.

▪ Small circumference chest, rib beading, poorly mineralized skull.

▪ Skull deformation from transducer pressure.

▪ Type III or IV may be recognized by bent femur.

RADIOGRAPHIC FEATURES

▪ Long bones

▪ Mild types of OI (I and IV)

▪ Thin, gracile bones.

▪ Relatively few fractures.

▪ Only mild shortening.

▪ Severe types of OI (II and III)

▪ Short, thick bones with multiple fractures.

▪ Often hypertrophic fracture callus.

▪ Prone to nonunion or malunion.

▪ Bowing, protrusio, coxa vara.

▪ Severe dwarfism

RADIOGRAPHIC FEATURES

▪ Skull

▪ Mild types may be normal

▪ Wormian bones (less severe types), delayed/absent

▪ calvarial ossification (severe types)

▪ Basilar impression of skull possible in any type, more common in type IV.

▪ Ribs

▪ Multiple fractures in severe form result in small chest with broad, deformed ribs.

▪ "Beading" from healed fractures variable in extent.

▪ Spine

▪ Platyspondyly.

▪ Kyphoscoliosis.

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