MSK Flashcards
achondroplasia is and path
congenital disorder resulting in rhizomelic dwarfism
FGFR3 mutation on chromosome 4p16.3 which causes abnormal cartilage formation
gain of function mutation with activation of inhib signal. all bones formed by endochondral ossification affected. membranous (like skull) normal.
Achondroplasia imaging
Antenatal
- short femur
- trident hand
- frontal bossing
- depressed nasal bridge
Cranial
- large vault, small base
- frontal bossing
- depressed nasal
- narrow FM
- comm hydrocephalus
Spinal
- posterior vert scalloping
- pregressive decreased interpedicular distance
- gibbus; kyphosis with bullet vert
- short pedicle canal stenosis
- widening IVD
Chest
- anteiror flaring
- AP narrowing of ribs
Pelvis
- horizontal acetabular roof
- tombstone iliac wings
- trident acetabulum
- champagne pelvic inlet
Limbs
- metaphyseal flaring
- rhizomelic shortening
Nail patella syndrome is
a rare AD condition results from symmetrical mesodermal and ectodermal abnormalities.
underlying genetic defect caused by loss of function mutation on LMX1B chromosome 9
XR
- hypoplastic/absent patella
- hypoplasia radial head/capitellum
- bilateral posterior iliac horns
- flared iliac crests with protuberant anterior iliac spines
Cleidocranial dysostosis is and imaging
rare polyostotic skeletal dysplasia caused by a CBFA1 gene mutation in AD inherited or sporadic mutation pattern
incomplete ossification of midline structures, including the clavicle and pubic bones
Skull
- wormians
- widened sutures/fontanelles
- basilar invag
- supernumery teeth
- abnormal ear structures
Chest
- absent/hypoplastic clavicles
- supernumery ribs
- hemivert with spondylosis
Pelvis
- iliac hypoplasia
- absent/delayed ossification pubic bone
Limbs
- short/absent fibular/raidus
- coxa vara
Melorheostosis is and pathology
aka leri disease. uncommon mesenchymal dysplasia manifesting as regions of sclerosing bone with dripping wax appearance
can be mono or polyostotic. tends to be monomelic. predilection for long bones. tendency for sclerotome distribution
Melorheostosis imaging
Classic
- periosteal cortical thickening
- endosteal thickening
- thick undulating ridges of bone (candle wax)
- confined to sclerotome
Osteoma like
Myositis ossificans like
Osteopathia striata like
Mixed
Mixed sclerosing bone dysplasia has features of
Melorheostosis
Osteopathia striata
Osteopoikilosis
Duchenne muscular dystrophy is
the most common muscular dystrophy
characterised by progressive muscle weakness and fatty replacement
x linked recessive pattern. DMD gene, encodes for dystrophin, becomes non fucntioning (more severe than Beckers)
Duchenne muscular dystophy imaging
fatty muscle replacement
scoliosis
hypoinflated lungs
cardiomegaly
gracile bones
MR
early invovlemnt of gastroc
eventual glutes, add magnus, then psoas, iliacus, quads, rectus, biceps, peroneus, soleus
sparing of; sartorius, gracilis, semitend, semimemb, tib posterior
Upper limb;
trics, bics, teres major, RC
spares; deltoid
Olliers disease is
a non hered skeletal disorder characterised by multiple enchondromas
should stop growingwhen the patient does, otherwise concern for malignant trasnformation
typically short tubular bones of hands and feet
Maffuci syndrome is
a congenital non hered mesodermal dysplasia characterised by multiple enchondromas with soft tissue venous malformations and/or spindle cell haemangiomas
somatic mutations in IDH1 or IDH2
Metachondromatosis is
the rare combination of multiple enchondromoatosis and osteochondromatosis (olliers and diaphyseal ecclasia)
Osteogenesis imperfecta is and path
a hetergenous group of congenital non sex linked genetic disorders of collagen type 1 production
disturbance in the synthesis of type 1 collagen, predominant protein of the extracellular matrix in most tissues
COL1A1 and COL1A2. can be AD, AR or sporadic.
can be mild, perinatal lethal or progressive deforming
hjallmark feature is osteoporosis and fragile bones that fracture easily. also blue sclera, dental frag and hearing loss
Osteogenesis imperfecta imaging
Head/spine
- basilar invag
- wormian bones
- scoliosis
- compression fractures
- codfish vert
- platyspondyly
Chest
- pectas ex or carinatum
- accordion ribs
Pelvis
- protusion acetabuli
- coxa vara
General
- severe op
- gracile bones
- cortical thinning
- popcorn calrc at meta/epiphysis
- zebra stipe sign (cyclic bisphosphonate therarpy)
- pseudoarthroses
Gracile bones ddx
NF1
Immobilisation
Muscular dystrophy
JRA
OI
Marfans
Homocystinuria
Haemophilia
NIMROD
- NF1
- Immob
- MD
- RA
- OI
- Dysplasia (marfans, homocystinuria)
- also haemophilia i guess
Wormian bones ddx
PORKCHOPS
Pyknodyostosis
OI
Rickets
Kinky hair
Cleidocranial dysostosis
Hypothyroid/hypophosphate
Otopalatodigital syndrome
Primary acroosteolysis (Hajdu Cheney)/ progeria
Syndrome of a Downs
Osteopetrosis is and path
AKA albers schonberg disease or marble bone disease
uncommon hered disorder. results from defective osteoclasts and overgrowth of bones. bones become thick and sclerotic, but more brittle
can crowd the marrow, resulting in myelophthisic anaemia and EMH/splenomaegaly
Features depend on subtype
- infantile AR osteopetrosis
- Benign adult AD osteopetrosis
Osteopetrosis types and imaging
AUTOSOMAL DOMINANT
- less severe type
- benign/adult
imaging
- bone in a bone
- erlenmeyer flask
- sanwich vertebrae
- alternating radiolucent metaphyseal bands
AUTOSOMAL RECESSIVE
- more severe, presents earlier
Imaging
- bone in bone
- triangle mandible sign
- defective dentition
- paranasal sinuses poorly pnematosised
- hyperteolrism
- dense inner table, low attenuation diploic, dense inner table
- hair on end
Bone in bone ddx
Normal
Cortical splitting and new periostitis
- sickle cell
- thalassemia
- gaucher
- chronic OM
- scurvy
Caffey disease
Abnormal metab
- hypothyroid
- hypparathy
- pagets
- acromegaly
- osteopetrosis
Disordered growth
- heavy metal
- hyper vit d
Subcortical osteopenia
- leukaemia
- mets
- complex regional pain syndrome
Oxalosis
Iatrogenic
- grafts
- bisphosphonate
Bone healing
Mnemonic: GHOST DRAGON
Growth arrest
Heavy metal/hypoparathy/hypothy
Osteopetrosis
Sickle cell, scurvy, syphillis
Thalessemia, TB
Disease of caffey, hypervit D
Rickets, radiation
Acromegaly
Gauchers
Oxalosis
Normal
Erlenmeyer flask deformity causes
AP OF DR GHLN
- achondroplasia
- Pyle disease
- Osteopetrosis /osteochondromatosis
- Fibrous dysplasia
- Down syndrome
- RA/RIckets
- Gaucher
- Hypophosphataemia, haemoglobinopathies
- Leukamia, lead poisoning
- Niemann Pick disease
Hair on end sign causes
HI NEST
Hereditary spherocytosis
Iron def anemia
Neuroblastoma
Enzyome def
Sickle cell
Thalassemia major
Osteopoikilosis is and assoc
sclerosing bony dysplasia characterised by multiple benign enostoses
often found with osteopathia striata and melorheatosis
Arthrogryposis is and assoc
descriptor that denotes congenital non progressive joint contractures invovling two or more body regions
Syndromes
- pena shokeir
- multiple pterygium
- fowler
- freeman sheldon
Non syndrome
- CNS anomalies
- NM disorders
Achondrogenesis is
a rare and extreme group of skeletal dysplasias
affects both bone and cartilage development
Can be AR or AD depending on type. May involving mutations in SLC26A2 and COL2A1 depending on type, or may be unknown.
Achondrogenesis imaging
fetal bony structures unable to be identified
extreme micromelia
can sometimes have calvarium, leaving a floating head appearance
additional
- micrognathia
- macrocephaly
- frontal bossing
- flat face
- anteverted nares
- long philtrum
- narrow thorax
- lung hypoplasia
- polyhydramnios/hydrops
Jeune syndrome is
aka asphyxiating thoracic dysplasia
rare short limb skeletal dysplasia characterised by contricted long narrow thoracic cavity
can be complicated by pulmonary hypoplasia, renal failure from cystic renal disease and hepatic cirrhosis
Jeune syndrome imaging
Thoracic
- short narrow elongated chest shape
- high riding clavicles
- irregular costochondral junctions
Skeletal
- dysplastic acetabula
- trident acetabula
- short flared iliac bones
- ischial/pubic spurs
- acromelia
- polydactyl
- short broad phalanges
Abdominopelvic
- cystic renal disease
- cystic pancreatic disease
- hepatic dysfx
Chondrodysplasia punctata is
a heterogenous group of skeletal dysplasia. calcific stippling of catilage and periarticular soft tissues is a common features.
Ellis van crevald syndrome is
aka chonddroectodermal dysplasia. rare skeltal dysplasia. type of mesomelic limb shortening.
mutations in either EVC1 or EVC2 on chromosome 4p16. AR with variable expression
Congenital pseudoarthrosis of hte tibia is
abnormal bowing that can progress to segmental bone loss simulating the appearance of a joint
aetiology is unclear but assoc with NF1
imaging
- progressive bowing
- short segment resorption
- angulation at absent bone segement
- mimics appearance of joint
Trevor disease is
aka dysplasia epiphysealis hemimelica. rare non hered disease characterised by osteochondromas arising from the epiphyses.
Fibrodysplasia ossificans progressiva is
aka munchmyer aka myositis ossificans progressiva. rare inherited characterised by progressive fibrosis and ossification of hte muscles, tendons, fascia, aponeuroses and ligaments. disabling and fatal.
Intramedullary osteosclerosis is
a sclerosing dysplasia assoc with increased bone formation within the medullary cavity. dx of exclusion
Mastocytosis is
excessive accumulation of mast cells in one or more organs
Mastocytosis imaging
Skeletal
- lytic, sclerotic or mixed
- diffuse invovlement is common
- sclerosis of axial skeletan and proximal long bones usually
Abdominal
- PUD
- diffuse small bowel thickening
- omental and mesenteric thickening
- hepatosplenomegaly
- ascites
- lymphadenopathy
Pulmonary
- nodules
Diffuse bony sclerosis ddx
3MPROOF
Malig
Myelofibrosis
Mastocytosis
Sickle cell
Pagets/pyknodysotosis
Renal osteodystrophy
Osteopetrosis
Other; sclerotic dysplasia, hyperthy, hypoparathy
Fluorosis
Pyknodysostosis is
aka toulouse lautrec syndrome aka osteopetrosis acroosteolytica
rare autosomal recessive bone dysplasia
characterised by osteosclerosis and short stature
def in cathepsin K, 1q21
Pyknodysotosis imaging
hands
- short stubby fingers
- “distal acroosteolysis”
- delayed bone age
Cranial
- delay in suture closing
- wormian bones
- frontoparietal bossing
- nasal beaking
Other
- vert sclerosis
- increased lumb lordosis
- vert segmental anomalies
- hypoplastic clavicles
Monteggia fracture dislocation is
ulnar shaft fracture
radial head dislocation
GRIMUS:
Gal: Radial fracture, Inferior dislocation
Mon: Ulnar fracture, Superior dislocation
Galeazzi fracture dislocation is
distal radius fracture
DRUJ dislocation/disruption
GRIMUS:
Gal: Radial fracture, Inferior dislocation
Mon: Ulnar fracture, Superior dislocation
Essex Lopresti fracture dislocation
radial head fracture
dislocated DRUJ
rupture of the interosseous membrane
Osteochondral defect is and aetiology
a focal area of cartilage damage and injury of hte adjacent subchondral bone plate and subchondral cancellous bone
aetiology
- osteochondritis dissecans
- avn
- subchondral insuff fracture
- impaction fracture
- post surgical
Osteochondral defects locations and staging
femoral condyle
humeral head
talus
capitellum
staging
1. limited to cartialge, subchondral oedema
- cartilage with subchondral fracture, no detachement
- detached, non displaced (rim sign)
- displaced
Osteochondritis dissecans is
end result of aseptic separation of an osteochondral fracment. gradual fragmentation of the articular surgace and results in an osteochondral defect.
majority thought to be related to trauma/microtrauma
Stress fracture is
fracture occuring due to mismatch of bone strength and chronic mechanical stress
can be
- fatigue; abnormal stress, normal bone
- insufficicency; normal stress, abnormal bone
Stress fracture imaging
location
- pars
- lower limb incl; femoral neck, anterior tibia, medial mall, talus, naviular, MTs (necks/base), hallux sesamoid
XR
- grey cortex sign
- increasing sclerosis or cortical thickening
- periosteal reaction/elevation
- fracture line
bone scan hot
MR
- periosteal soft tissue oedema
- band like bone marrow oedema
- t1 hypointense fracture
Insufficiency fracture is and causes
normal stress abnormal bones
includes looser zones
causes
- OP ++
- hyperparathy, dm, osteomalacia
- pagets, osteopetrosis
- marfans, FD
- meds; glucocorticoids, chemo
- radiation therapy
Bisphosphanate related fracture criteria
located in femoral diaphysis
major ft
- no or minimal trauma
- mainly transverse/oblique
- lateral cortex, medial spike
- no or minimal comminution
- endosteal thickening
minor ft
- diaphyseal thickening
- bilaterally
- prodromal sx
- delayed healing
exclusion cr
- not spiral/comminuted
- nor neck or intertrochanteric
- no underlying bone process
- not periprosthetic
Looser zones are
wide transverse lucencies with sclerotic borders traversing partwqay through a bone, usually perpindicular to cortex.
assoc with rickets and osteomalacia
type of insuff fracture. highly suggestive with symmetric and in classic loc; axialla scapula, rib, post ulnar. rami. medial femoral neck.
morel lavelle lesions are
closed degloving injuries assoc with severe trauma presenting as a haemolympathic colleciton or mass
diffuse bony sclerosis causes
3 m,s proof
Malig
Myelofibrosis
Mastocytosis
Sickle cell
Pagets/pyknodysotosis
Renal osteodystrophy
Osteopetrosis
Other; sclerotic dysplasia, hyperthyroid, hypoparathyroid
Fluoresis
diffuse bone marrow infiltration causes
MLML
mets, myeloma
lymphoma
myelofibrosis, mastocytosis
leukaemia
Primary myelofibrosis is
myeloprolif neoplasm. replcaement of bone amrrow with collagenous connective tissue and progressive fibrosis
characterised by
- EMH
- splenomegaly
- anaemia
- variable change in no of granulocytes and platelets
chronic clonal stem cell disorder. considered a chronic BCR ABL1 negative myeloproliferative disorder
Primary myelofibrosis imaging
osteosclerosis; axial, ribs, proximal humerus and gemur
superscan
hepatosplenomegaly
splenic infacrts
portal hypertension
complications
- gout
- splenic stuff like rupture or infarct
- bleeding
- thromboembolism
Hip AVN classification
Ficat and Arlet classification
Stage 0
- xray normal
- mri normla
- clinical normal
Stage 1
- xray osteopaenia
- MRI oedema
- bone scan uptake
- clinical pain
Stage 2
- xray mixed osteopaenia/sclerosis/cysts. no subchondral lucency
- mri geographic defect
- bone scan uptake
- clinical pain and stiffness
Stage 3
- xray crescent sign and cortical collapse
- MRI same
- clinical pain and stiffness, rad to knee
Stage 4
- xray end stage with degenerative change
- mri same
- clincial limp
AVN/osteoneocrosis signs
Double line
- two serpentine lines
- inner bright, outer dark
- granulation and sclerosis
Rim sign
- high T2 line between two low signal lines
- fluid between sclerotic borders of an osteochrondral fragment
Crescent sign
- subchondral fracture in setting of osteonecrosis
- curvilinear lucent subchondral line
- if articular surface flattening, suggests impending articualr collapse
AVN/osteonecrosis causes
PLASTIC RAGS
Pancreatitis, pregnancy
Lupus
Alcohol
Steroids
Trauma
Idiopathic/infection
Caisson disease, collagen vascular disease
Radiation, RA
Amyloid
Gaucher
Sickle cell
Ahlback disease
medial femoral condylkar avn
Brailsford disease
radial head avn
Buchman disease
iliac crest avn
Burns disease
distal ulnar avn
Caffey disease
entire carpus or intercondular spines of tibia avn
Dias disease
trochlear of talus avn
Friebergs infraction
MT head avn
Friedrich disease
medial clavicle avn
Haas disease
humeral head avn
Iselin disease
base of 5th MT avn
Kienbock disease
lunate avn
Kohler disease
patella/navicular (children) avn
kummell disease
vertebral body avn
legg calve perthes disease
femoral head avn
Mauclaire disease
metacarpal head avn
Muelle weiss disease
navicular (adult) avn
Panner disease
capitellum humerus avn
Peiser disease
scaphoid acn
sever disease
calcaneal epiphysis avn
thiemann disease
base of phalanges avn
Bone infarct imaging and ddx
XR
- sheet like central lucency with shell like sclerosis and serpiginous border
MR
T1
- serpiginous low signal
- peripheral rim enhancement
- central signal marrow
T2
- acute; ill defined high signal
- double line sign
- central signal that of marrow
Gradient
- double line
DDX
- Enchondroma; chondroid matrix, central marrow signal absent
healing NOF
normal red marrow
marrow tumour
Klippel trenaunay weber is
a rare congenital disorder characterised by
- venous malformations
- cutaneous capillary malformations, and
- limb overgrowth
primary bone lymphoma is
less common than secondary. <5% bone tumours. <1% NHL. Typically DLBCL.
Osteomyelitis imaging
Specific types/findings:
- subperiosteal abscess
- brodies abscess
- pott puffy tumour
- sclerosing osteomyelitis of garre
General
XR
- swelling/loss of normal soft tissue planes
- joint effusion
- regional osteopaenia
- perisoteal reaction/thickening
- focal bony lysis or cortical loss
- endosteal scalloping
- loss of trabecular bone architecture
- eventual formation of sequestrum, involucrum and cloaca
MR
T1
- intermediate to low fluid centrally
- low marrow signal
- cortical destruction
T2
- bone marrow oedema
- high T2 fluid
C+
- post con enhancement of marrow, abscess margins, periosteum, etc
penumbra sign
- rim lining of abscess cavity representing vascularised granulation tissue. usually muscle signal t1 and enhancing.
ddx
- charcot
- mets
- primary neoplasm eg; eqings, osteosarc, lymphoma, mm
- lch
Septic arthritis imaging
XR
- effusion
- juxta articular osteopaenia
- narrowing of joint space
- destruction of subchondral bone
US
- joint effusion
- can have debris
- perisynovial vascularity
MR
- T1 low in bone
- T2 subchondral/pericapsular oedema
- C+ synovial enhancement, pericapsular enhancement
Leprosy is and imaging
chronic infectious disease caused by mycobacterium leprae. attacks skin and peripheral nerves. characteristic invovlement of hands and feet.
imaging
- similar to other conditions where sensory impairment is complicated by traumatic injury and infection e.g. charcots
- motor denervation; clawed fingers/toes
- bone absorption; decreased length and tapered end “licked candy stick”
Polio is and imaging
rare disease from poliovirus infectioin
imaging
- atrophy of involved areas, including bone and muscle
- similar to other NM disorders
- neuroimaging; ALS like abnormalities in the ventral motor tracts in spine and/or motor cortex
Madura foot or maduramycosis is
caused by fungal infection
extensive destructive/lytic changes
MR/US dot in a circle sign
Rheumatoid arthritis is
a chronic autoimmune multisystem inflammatory disease that affects many organs
clinical
articular
- symmetric deforming polyarthropathy
- fingers and hands
extra articular
pulmonarry
- interstial lung disease
- pulmonary nodules
- caplan syndrome
CV
- pericarditis
- atherosclerosis
cutaenous
- rheumatoid nodules in pressue areas
- rheumatoid vasculitis
haem
- anaemia of chronic disease
- felty syndrome (RA, splenomeg, neutropaenia)
occular
Rheumatoid arthritis path
unknown aetiology, probably multifactorial
genetic predisp; eg HLA DR B1
environmental trigger eg EBV
leads to autoimmune response directed against synovium and organs
activation and accumulation of CD4 T cells starts cascade
- activation of macrophages, synovial cells and production of cytokins. prolif synovial cells. increased prod of destructive enzymes
- activating b cell lymphocytes prod antibodies invluding RF. makes immune complexes which deposit in tissue
- directly activate endothelial vells, increases adhesion and accum of inflamm cells
- producing rankl, activates osteoclasts
leads to pannus formation; oedematous thickened hyperplastic synovium infiltrated with inflamm cells. gradually erode bare areas initial, followed by articular cartilage
Markers
- RF
- anti CCP, ACPA
- CRP/RSR
Rheumatoid arthritis MSK imaging
General
- marginal erosions
- soft tissue swelling
- osteoporosis, juxta articular
- symmetric joint space narrowing
Hands
- PIP/MCP. ulnar styloid. triqutrum
- DIPS spared
- sublaxation; ulnar MCP dev. outonniere and swan neck
- hitchhiker thumb deformity
- carpal insdtab
- ankylosis
- scallop sign; ulnar aspect distal radius, predicts extensor tendon rupture (vaughn jackson syndrome)
- pencil in cup
Elbow
- effusion
- narrowing
- periarticular erosions
- cysts
Feet
- similar to hands, pred for PIP and MCT (4th and 5th)
- subtalar joint involvemt
- hammar toe deformity
- hallux valgus
Shoulder
- distal clav erosion
- marginal humeral head erosive
- high riding shoulder
Hip
- joint narrowing, concentric
- acetabular protrution
Knee
- effusion
- joint space narrowing
- no OA changes
Spine
- dens erosion
- atlantoaxial subluxation
- atlantoaxial impaction
- fact joint erosion/fusion
- osteoporosis and fractures
MR
- synovial hyperaemia
- synovial hyperplasia (rice bodies)
- subchondral cysts and erosions
- juxta art oedema
- effusions
RA MSK DDX
OS
- PIP DIP
- JOSS
- soft tissue sqwlling; hebberend DIP bouchard PIP
- no erosions
EOA
- PIP DIP and CMC1
- central erosions
PSA
- IP predominant
- marginal erosions, classic pencil in cup
- OP not a feature
Reactive arhritis
- lower limb pred
- osteopaenia, OP, JSN, cysts, sublucation
- marginal erosions
- similar distribution
SLE
- JSN, sclerosis, osteophytes
- ulnar deviation without erosions
CPPS
- usually MCPJ
- chondrocalcinosis and no eorsions
Gout
- punched out erosions
- tophi
Rice bodies aetiology and ddx
aetiology
- RA
- TB, infecvtion, JIA
- chrnoic synovitis
- chrnoic burisits
ddx
- synovial chrondromatosis
Distal clav erosion ddx
Bilateral
- atraumatic from microtrauma
- HyperPTH
- RA
- scleroderma
- PSA
- pyknodysotosis
- progeria
Unilateral
- RA
- post trauma
- myeloma
- met
-OM
Dens erosion ddx
RA
SLE
CPPD
Gout
OA
Infection
Hyper PTH
tumours
T21
Vaughn jackson syndrome
extensor tendon rupture in context inflammatory arthropathy, usually RA
ank spond is
a seronegative spondyloarthropathy. results in fusion of the SIJ and spine.
associ
- uveitis
- psoriasis
- IBD
- osteopaenia
- CV disease
- upper lobe interstitial lung disease
- aortitis
- secondary amyloidosis
- cauda equina
RF negative. HLA B27 implicated.
ank spond imaging
SIJ
- sacroilitis
Spine
- romanus lesion (shiny corner)
- vertebral body squaring
- non infectious spondylyodiscitis (anderson lesion)
- bamboo spine
- dagger spine
- dural ectasia
Hips
- whiskering of ligaments, particularly ischial tuberosities
- bridgind of PS
Shoulders
- anterlateral humeral head erosion; hatchet deformity
Chst
- progressive fibrosis and bullous change at the apices
- cardiomegaly
enteropathic arthritis is
chronic inflamm arthritis. seronegative. assoc with ibd.
peripheral joints, sacroiliac joints, spondylitis similar to ank spond
juvenile idiopathic arthritis is and path
most common chronic arthritis of childhood and corresponds to a group of subtypes
still disease; systemic onset, intermittent spiking fevers. salmon rash. hepatosplenomegaly.
path
several subtypes
oligo JIA
- <4joints first 6mo
- 1-6yo
- medium and large
polyartciular
- >5 joitns
- 1-4, 7-10
- small and medium joints
systemic (still disease)
- systemic sx
- arthritis weeks or months after
Juvenile idiopathic arthritis imaging
soft tisue swelling
osteopaenia
joint space narrowing
erosions
growth disturbances
sublaxation
cervical
- atlantoaxial sublux
- odontoid eorosions
- anklyosis
hepatosplenomegaly. pericardial and pleural effusions
knee; widedned intercodylar notch (like haemophilic andnTB)
can have synovial changes and rice bodies on MR
Adult onset still disease
rare multisystem inflamm condition. initially thought a variant of paediatric stills.
triad of
- high fevers
- arthralgia
- salmon coloured rash
negative RF and ANA
psoriatic arthritis is and path
seronegative spondyloarthropathy
inflamm arthritis assoc with psoriaisis
assoc
- obesity
- htn
- t2dm
- hyperlipiadmiaea
path
- 60% HLA B 27 p[ositive
- uveitis and conjunctivitis
- cardiac rhythmn disturbance
- urethritis, prostatitis, balanitis, cevicities, vaginitis
psoriatic arthritis imaging
hallmark ios erosive change and bony prolif. predominantly distal distribution
hands feet, sij and spine. bigger joints less common.
can be symmetric poly or asymm oligo
- enthesitis
- marginal erosions
- pencil in cup defomity
- porlif; fuzzy appearance around joint
- joint subluxation
- periostitis
- dactylitis; sausage digit
- acroosteolysis
- arthritis mutlians
- ivory pahalnx
- sacroilitis
reactive arthritis is
sterile inflammatory monoarticular or oligoarticular arthritis. follows infection at different site, commonly enteric or urogenital. seronegative
clinical
- arthritis
- conjunctivitis
- urethritis
cant see cant bee sore knee
enteric
- yersinia, salmonella, shigella, campylobacter
sex
- chalmydia
other
- brucellosis
reactive arthritis iamging
distal preferred knee>MTP>calcnaeus?>ankle>SIJ
enthesitis at achilles and plantar fascia insertions
bulky poaravertebral floating osteophyte
similar to psoriatic; erosions, enthesopathy, prolief, juxtaarticula osteopeorisi, uniform JSN, fusiform soft tissue swelling
Scleroderma is and path
autoimmune ctd characterised by multisystem fibrosis and soft tissue calcification
widespread deposition of collagen and other extracellular matrix proteins. believed to occur as a result of an abnormal immune response. small vessels involved early, dense capillary network. perivascular fibrosis and gradual luminal stenosis
assoc
- crest
- other ctd; sle, polymyositis, dermatomyositis
esr, rf,ana
Scleroderma MSK
bone
- acroostelysis
- periarticular osteopaenia
- JSN
- erosions
- CMC joint resorption and radial subluxation
- pencil in cup
soft tissue
- subcut and periarticular calcification
- flexion contractions
- atropgy at tips of fingers
other
- rib resorption, mandibule, radius and ulnar
- terminal phalanfeal sclerosis
Felty syndrome is
RA
splenomegaly
neutropaenia
SANTA
- spoleno
- naeamia
- neutorpaneia
- thrombocytopaenia
- arthritis
OA classification
primary
- absence of antecedent insult
- strong genetic component
secondayr
- abnormal mechanical force
- previous joint injur
= post trauma
= prior surgery
= CPPD
= inflamm arthritis
= haemochromatosis
Ganglion cyst is and classification
non malignant cystic masses. occur in assoc with MSK structures. most common soft tissue mass of the hand and wrist.
path unclear. thought result from myxoid degeneration of CT assoc with joint capsules and tendon sheaths
classification
bone
- intraosseous
- periosteal
- soft tissue
joint
- intraarticular
- juxtaarticular
nerve
- intraneural
locations
- most common hand and wrist
- dorsum wrist 60%
- also volar, flexor sheath, DIPJ
other notable
- spinoglenoid notch ganglion
- acl ganglion
- ankle/foot
Ganglion cyst imaging
US
hypo and well defined
MR
- uni or multilocular
- fluid signal
- adjacent to joint or tendon
- can be t1 variable but usually low
- T2 hjigh
- rim enhancement
synovial cysts are
paraarticular fluid filled sacs or pouch like structures containing synovial fluid and lined by synovial membrane.
Charcot joint is and path
aka neurpathic joint. progressive degen/destruction in patients with abnormal pain and proprioception
path
- inflamm response from minor injury
- results in osteolysis
- can be atrophic or hypertrophic
atrophic
- most common
- earlier
- acute
- reabsorption ends of bone
- joint destruction with resorp fragments
- absent ostesclerosis and osteophytes
- non wt bearing joints
hypertrophic
- sensory nerves affected
- slow progression
- destruction with periarticular debris
- presence of osteosclerosis and osteophytes
- absence of osteopeorosis, unless also infected
Charcot joint aetiology
DM
Syringomyelia
neurosyphilis
spinal cord injury
alcohol
tumours compressing nerves
amyloid
pernicious anaemia
polio
leprosy
ms
steroids
charcot marie tooth
S mnemonic
- sugar
- syphillis
- steroid
- syringomyelia
- spinal cord injry
- spina bfida
- scleroderma
- scaly disease (leprosy)
- spirit (etoh)
Charcot joint imaging
Xr/CT
- destrutive and disorganising
- centred on joints
- development/fragmentation/dissolution; subchondral osteopaenia, bone frag, joint malalignment
- coalesnece; subchondral sclerosis, periosteal bone formation, fusion of larger fragments
- reconstruction; remodelling with rounding of fragments and ankylosis
MR
T1
- joints swollen, decreased signal
- fat planes adjcent to ulcers low
C+
- inflammatory areas ehance with central necrotic non enhancement
STIR
- early; increased
- later; loss of cortical outline and cortical destruction
features suggesting infection
- sinus tract
- diffuse marrow abnor
- replcaement of soft tissue fat
- thick rim enhancemnt
- joint erosions
- ghost sign - poor def of the margins on the bone, blending with the surrounding ingflamm and phlegmon. becomes visible post con
6 D’s
- density
- destruction
- debris
- distension
- disorganisation
- dislocation
Paget disease is and path
common chronic metabolic bone disorder characterised by excessive abnormal bone remodelling
classicaly expanded bone with coarse trabec. pelvis spine skull and prox long bones.
disease of osteoclasts. aetiology unknown. viral infection (paramyxovirus) and genitic suscep postulated
three stages
- early destructive (lytic, clast)
- intermediate (active/mixed, blastic and clastic)
- late (inactive, sclerotic/blastic)
Pagets disease imaging
Skull
- osteoporosis circumscripta
- cotton wool
- diploic widending (inne and outer)
- tam o shanter
spine
- picture frame
- squaring vertrabe
- verticle trabec thickening
pelvis
- sclerosis of iliopectineal and ishipubic; pelvic brim sign and obliteration of kohlers teardrop
- acetab protrusion
- enlarged rami/ischium
Long bones
- blade of grass
- lateral curvature gfemur
- anterior curvature tibia
bone scan
- marked uptake all phases
- micky mouse; vert bodies and posterior elements
- lincoln; diffuse mandible forming a bearded appearance
Pagets disease complications
osseous weakinging and fractures
oa
hearing loss
- sensi from compression
- cond from dixation
neural compression
osteosarc
gct in skull
high outpiout heart failure
hperPTH
EMH
banana fracture
horizontal path fracture in pagets
basilar invagination ddx
PF ROACH
pagets
fd
RA/rickets
OI
achondroplasia
Chiari 1 and 2, cleidocranial dysostosis
hyperpth
ivory vert dd
LIMPH
lymphoma
infection
mets and myelosclerosis
pagets
haemangioma
Rickets is and path
deficient mineralisation of the growth plate in paeds
abnormalities in ca po4 homeostasis disrupt endochondral ossification
calcipenic
- high pth
- low ca
- low po4
phosphopenic
- low pth
- normal ca
- low po4
calcipenic
- vit d def
- dietary ca def
- defective vit d metabolism
- hereditary vit d resistance
phosphopenic
- hereditary hypophos rickets
- tumour induced rickets
- fanconi
Rickets imaging
growth plate widening
- fraying
- splaying
- cupping
- pseudofractures (looser zones)
concurrent osteomalacia
- limb bowing
- drawn in lower ribs (harrisons sulcus)
- rachitic rosary anterior ribs
- codfish vertebra
post treatment
- harris growth arrest lines
Hyperparathyroidism is, assoc and causes
effects of excess pth. can be primary secondayr or tertiary
assoc
- men1 and 2a
- familial hypocalciuric hypercalcaemia
- hyperparathyroidism jaw tumour syndrome
primary
- parathyroid adenoma
- parathyroid hyperplasia
- parathyroid carcinoma
- parathyromatosis
secondary
- chrnoic hypocalcaemia with renal osteodystrophy most commonly (also vit d def, malnurtirtion) resulting in parathyroid hyerplasia
tertiary
- autonomous parathyroid adenoma caused by chronic overstimulation of hyerplastic glands in renal insufficiency
Hyperparathyroidism imaging
subperiosteal bone resoprtion
- radial prox/mid phalanges 2/3rd
- medial tibia, femur, humerus
- lamina dura; floating tooth
subchrondral resorption
- lateral clavicles
- ps
- sacroiliac joints
subligamentous resorption
- ischial tub
- trochanters
- inferior surface calc and clavicle
intracortical resoption
- cigar shaped lucency in cortex
terminal tuft erosion
rugger jersy spine
osteopaenia
brown tumours
salt and pepper skull
chondrocalcinosis
Renal osteodystrophy is and imaging
aka uraemic osteopathy. constellation of msk abnormalities in patients with crf due to concurrent
- osteomalacia/rickets
- secondary hyperparathyroidism
- aluminium tox (if on dialysis)
imaging
- osteopaenia
- salt and pepper skull
- demineralisation; subperiosteal, subligamentous, cortical or trabec
- bone sclerosis; diffuse, rugger jersey
- soft tissue calcification
- amyloid deposition periarticular
- insuff fractures
- looser zones
- brown tumours
Gout is and path
crystal arthropathy due to deposition of monosodium urate cystals in and around joints
monosodium urate crystals in periarticular soft tissues. needle shaped and negatively biorefringent. needles are chemotactic and activate complement
primary risk factor is hyperuricaemia. two main mechanisms
undersecretion of uric acid
- ckd
- hypertension
- hyperpth
- alcohol
- drugs
- lead poisoning
- obesity
overproduction of uric acid
- myeloprolifer
- haemolysis
- exercise
- lesch nyhan syndrome
calcium pyrophosphate dihydrate deposition disease is and path
cppd disease is cooccurence of arthritis with cppd deposition in articular cartilage
weakly positively birefringenet. rhmboid or rod shaped.
Causes:
Idiopathic
Hereditary
Secondary
- haemochromatosis
- hyperpth
- hypothyroid
CPPD imaging
OA unusual distribution
- wrist joint (can get SLAC)
- MCPJ, hook like osteophytes
- patellogemoral
- shoulder
- elbow
chondrocalcinosis
Transient osteoporosis of the hip is
self limiting clinical entitiy, idiopathic, synonym of subchrondral insuff fracture of the knee
present with hip pain, progressive over several weeks and spontaneous onset. do not go on to have avn. can have migratory change after; regional migratory osteoporosis
Transient osteoporosis of the hip imaging
XR
- subchrondral cortical loss femoral head and neck
- profound osteopaenia
- joint effusion
- JS preserved
MR
- bone marrow oedema head and neck
- no osteonecrosis
- subchondral fractures in half of cases
- sparing of the medial femoral head
Bone marrow oedema syndrome of the foot and ankle is
aka transient bone marrow oedema syndrome of the foot and ankle
self limited patchy bone marrow t2 hyperintensities of unknown aetiology
related to transient osteoporosis of the hip and regional migratory osteoporosis
most frequently involves the talus but can be any of them
Regional migratory osteoporosis is
rare arthralgia affecting weight bearing joints of the lower limb
non traumatic pain, peaks at 2 months and resolves. subsequent pain in another joint 2-10 later.
Complex regional pain syndrome is and path
aka sudeck atrophy. affects the extremities, wide clinical spetrum
two types
- type 1; no underlying single nerve lesion (reflex sympathetic dystrophy)
- type 2; underling nerve lesion identified
aetiology
- trauma (minor)
- surgery
- idiopathic/immobilisation
- cns disorders
- MI
Complex regional pain syndrome imaging
hands and feet distal to injury
XR
- severe patchy osteopaenia, periarticular
- soft tissue swelling and eventually atrophy
- subperiosteal bone resoprtion
- preservation of joint space
MRI
- patchy bone marrow oedema
- soft tissue oedema and enhancement
- skin thickening
- joint effusion
- synovial hypertropgy
- muscle atrophy (late)
NM
- increased tracer all three phases
- diffusely increased juxtaarticular activity all joints affected hand or foot
Hydroxyapatite deposition disease is and imaging
disease of uncertain aetiology where there are periarticular and intraarticular calcium deposits. usually tendons. shoulder most often.
imaging appearance varies based on stage; formative, resting, resoprtive. Formative and resting appear as round to ovoid calcification with well defined borders. resoprtive ill defined with comet tail.
Thyroid acropachy is and imaging
unusual pres of thryoid disease, usually graves and assoc with orbitopathy
imaging
- hands and feet
- tubular bones
- bilateral and symmetrical
- prominent smooth flowing periosteal reaction with new bone formation
- soft tissue swelling
ddx
- hpoa
- pachydermoperiostosis
- chronic vascular insuff
- hypervita
- fluorosis
Hypoparathyroidism imaging
MSK
- focal and generalised osteosclerosis
- dense metaphyseal bands
- skull vault thickening
- dish like chages
- subcut calcification
CNS
- intracranial calcs, bg
- cataract
Osteoradionecrosis is path and imaging
severe delayed radiation induced injury, characterised by bone tissue necrosis and failure of healing
microvascular damange, usually large radiation dose and in mandible
imaging
mandible
- ill defined cortical destruction without sequestration
elsewhere
- osteopaenia
- disorganisation and coarsening
- cortical irreg
- heterogenous bone density
Intraossoues haemangioma is, path and location
benign tumours of vascular channels arising in bone
thin walled blood vessels with lining of single non atypical endothelial cells. hamartomatous vascular tissue within endothelium surrounding bone trabeculae and permeating marrow. can contain fat, muscle, fibrous and thrombi
benign and slow growing but can be locally aggressive
vert, skull, facial bones
long bones meta/dia
Unicameral bone cyst is, path and location
common benign non neoplastic lucent bony lesiosn., typically seen in childhood and asx. can present with path fracture. usually 1-2nd decade.
simple cyst lacking true lining with typical features.
usually remains adjacent ot eh growth plate and migrates away and it resolves
location
- proximal humerus most
- prox femur next
- other long bones
- can be; spine, pelvis, calcaneus, iliac wing
Myositis ossificans is, path and imaging
most common form of heterotopic ossification, usually in large muscles.
typically young adults resulting from trauma. can be in paraplegics
path
- metaplasia intramusclar connective tissue resulting in extraossoues bone formation
- granualtion tissue with fibroblastic and osteoblastic diff and osteoid formation
- mineralised osteoid matric develops with immatuure lamellar bone
- immune bone progfresses into mature lamellar cortical and trabecular
xr
- soft tissue swelling
- progressive calcs by 2-6 weeks
- classic at 2 months
- then smaller
MR
T1 ill defined
T2
- high signal peripheral up to 8 weeks
- central heterogenous low signal
- can have fluid levels
C+ enhancement often
Late
T1
- central high, peripheral low
T2
- peripheral low, central intermediate to high
C+ none
ddx
parosteal
- calc in centre and cont to periphery
soft tissue sarcomas
Juxtacortical chondroma is and imaging
aka periosteal chondroma. rare benign chondral tumours arising from the periosteum of tubular bones. typically humerus, femur and other extremity bones
XR
- saucerisation with sclerotic periosteal reaction
- matrix calc in 50%
- <3cm typically
MR
- abutting cortex, pressure erosion neighboouring bone
- lobulated
T1: low to muscle
T2: high with low foci of calc
C+ heteorgenous, peripheral predominant
ddx
- periosteal osteosarcoma; lobulated margins and high t2 absent
- non epiphyseal chondroblastoma; reactive marrow
- juxtacrotical chondrosarcoma; larger
- bizarre parosteal osteochondromatous prolif BPOP; nora lesions; phalangeal
- cortical desmoid
- tenosynovail GCT
ENchondroma is and path
aka chondromas. common intramedulla cartilage neoplasms with benign features. share histo features with low grade chondrosarc
10-30yo. most common of the hand and wirst
assoc
- olliers
- maffuci
path
- lobules of mature hyaline cartilage
- partially or completely encased in normal bone
- arise from rests of growth plate cartialge which become isolated within mature bone
- no histo evidence of invasion
location
- small tube bones hands/feet
- large tube bones
- rare; pelvis, ribs, scap,l sternum
rarely may extend through cortex and demonstrate exophytic growth; enchondroma protubernas
Enchondroma protubernas is
aka ecchondroma. rare form of enchondroma with growth pattern leading to deformity and remoddeling of the cotrex
Olliers disease is
non hered sporadic skeletal disorder characterised by multiple enchondromas
Metachondromatosis is
rare combinationof multiple enchondromas (Olliers) and osteochondromas (diaphyseal aclasia)
Maffuci syndrome is
congenital non hered mesodermal dysplasia characterised by multiple enchondromas with soft tissue venous malformations and/or spindle cell haemangiomas
Chondrosarcomas are and apth
malignant cartilaginous tumours. older patients and long bones. can be primary or arise froim existing chondroid neoplasm.
histo differs according to subtype. typically multilobulated with central high water and peripheral endochondral ossification
Subtypes
Primary
- convenital intramedullary; low, inter or high grade
- juxtacortical; l, i, h
- clear cell
- mycoid; i
- mesenchymal; h
- extraskeletal
- dediff
Secondary
- osteochondromas
- enchondromas
locations
- long bones
- pelvis
- ribs
- spine
- scapula
- sternum
- head and neck
- craniofacial
Chondrosarcomas imaging
XR
- lytic
- intralesional matrix
- endosteal scalloping
- moth eaten/permeative
- cortical remodelling
CT
- matrix
- endo scalloping
- cortical breech
- soft tissue mass
- heterosgenous enahcnement
MR
- T1 low to inter
T2 high af
SWI blooming of mineralisation part
C+ heterogenous to intense
Fibrous dysplasia is and path
developmental benign medulary fibroosseous process characterised by failure to form mature lamellar bone and arrest s woven bone
assoc
- mccune albright
- isolated endocrinopathy
- mazabraud syndrome
can be mono or poly ostotic
path
- altered osteogenesis leading to intramedullary fibroosseous prolief with fibrous and osseous componetsn presnet in various derees
- linked to GNAS mutation
Location
Mono
- ribs
- femur
- tibia
- craniofacial
- humerus
Poly
- unilateral/monomelic
- femur
- tibia
- pelvis
- foot
- ribs
- skull and fbs
- upper extremities
- lumbar spine
- calvicle
- cervcle spine
Fibrous dysplasia imaging
TGeneral
- intramedullary, expansile
- well defined borders
- smooth cortical contour
- endosteal scalll
XR
- cystic, sclerotic or mixed
- smooth and homogenous
- endosteal scalloping and cortical thiining
- other; ground glass matric, no periosteal reaction, rind sign
MR
- not useful
- t1 intermediate to low htero
- t2 variable
- hetergenous enahncemnt
ddx
pagets
- diff demo
nf1
- usually vert column. ribbon ribs.
osteofibrous dysplasia
- usually tibia with anterior boweing, begins in cortex, young children
adamantinoma
- tibial
nof
ubc
gct
enchondroma
haemangioma
mccune albright
endocrinopathy (precocious puberty)
polyostotic fibrous dusplsia
cage au lait spots
mazabraud is
fibrous dysplasia
intramuscular myxomas
Non ossifying fibroma is and path
benign osteoclastic giant cell rich bone tumours. metaphyseal. children and adolescents.
assoc
- nf1
- jaffe campannuci syndrome
path
- bnign spindle cell tumours
- osteoclast like giant cells
- can fill up with bone
- mutations in KRAS and FGFR1 genes
- spindle shaped cells in storiform pattern
- haemosiderin deposition, foamy macrophages
location
- metaphysis or long bones
- less common in flat pelvic bones and mandible; might represent a gct with regressive change
Non ossifying firboma imaging
XR
- polycystic multiloculated lucent lesion
- eccentric in metaphysis
- thin sclerotic rim
- paralell to axis of bone
- migrate with age away from physis
- progressively sclerotic
MR
- depends on stage of develoepemnt
- initially high to inter t2 with peirpehral low
- becomes low on all
Intraosseous lipoma is and path
rare benign lesions. wide age range. slight male.
aetiology unknown. almost excluysively medullary cavity, usually of long bones. mature adipoctes without admixed haematopoietic tissue or bony trabeculae
location
- calcaneus
- fgemur (intertrochanteric)
- tibia
- fibula
- upper limb
- skull and mandible
- spine and pelvis
- ribs
Intraosseous lipoma imaging
XR
- benign appearing osteolytic with well defined margins
- central calcs; cockade sign
CT
- fat containing lesions
- can be homogenous, heterogenous with sclerosis and calcification/ossification
Macrodystrophia lipomatosis is, path and imaging
rare form of localised giganticism. non hered. assoc with syndactyly, clinodactyly and polydactyly.
marked increase in all mesenchymal elements, dominanted by adipose tissue in a fine fibrous network
Imaging
XR
- splayed, lengthened and broaded phalanges with endosteal and periosteal bone deposition
- overlying soft tissues arre markedly overgrown
- focal fat may be seen
MR
- fibrous strands seen within
- cortical thickening
- osseous hypertrophy
- bony outgrowths
- neural thickening
DDX
- NF1
- Fibrolipomatous hamartoma of the median/ulnar nerve
- Vascular malformation; haemangioma (incl Maffuci), AVm, KTW
- chronic hyperaemia; JRA, haemophilia
- Hemihypertrophy/BWS
- Russell Silver Dwarfism
Lipoma arborescens is and imaging
rare condition affecting synovial linings of the joints and bursa with frond like deposition of fatty tyissues
normal synovium replaced by hypertrophied villi demonstrating markeddeposition of mature lipocytes
Imaging
XR
- assoc effusion
- can see degen change
- cam see fatty lucencies in soft tissue lesion
CT
- low density intrarticular mass
- non enhancing
MR
- fat containing frond like synovial mass, follows fat on all sequences
DDX
- loose bodies
- synovial osteochondramosis
- intraarticular tenosynovial giant cell tumour (low on T2, non fat signal)
- synovial haemangioma (enhances, FF levels)
- synovitis (no fat signal)
Osteomas are and imaging
benign bone tumours. unknown aetiology. common. composed of lamellar/cortical type bone
locations
- paransal sinuses
- skull vault
- mandibular
- nasal bone
when multiple consider Garnders
XR
- ivory, round, dense. mature may have central marrow
MR
- low on all
ddx
- exostosis
- cementoosseous dysplasia
- pagets
- sclerosing osteomyelitis of garre
- osteoblastoma
- ossifying fibroma
- osteosarc
- fd
- odontoma
Osteoid osteomas are, path and imaging
benign bone forming tumours, typically in children and adolescents. characteristic lucent nidus and surrounding reaction. night pain relieved with nsaids
three parts concentric
- nidus, representing the neoplastic process
- fibrovascular rim
- surrounding reactive sclerosis
location
- long bones; femur and tibia
- phalanges
- vertebra, posterior elements
FOS gene rearrangement
XR
- solid periosteal reaction with cortical thickening
- can sometimes see nidues
CT
- lucent nidus within surrounding slcerotic reactive bone. central small scelrotic dot
NM
- double density, hotter spot within hot area
DDX
- osteomyelitis/brodies abscess
- osteoblastoma (bigger)
- stress fracture
- cortical desmoid
- osteochondroma
- osteosarcoma
- bone island
- localised cortical thickening
- intracrotical haemangioma
Osteoblastoma is, path and imaging
rare bone forming tumours. may be locally aggressive. compared to osteoid osteoma, larger, more frequently axial
locally aggressively, histo similar to osteoid osteomas. scoliosis. minimal response to nsaids. bone and osteoid forming with a rim of osteoblasts and vascular
location
- spinal volumn, posterior elements
- meta/dia in long bones
FOS gene rearrangement
Imaging
typically larger than 1.5-2cm
XR
- predom lytic with rim of reactive scelrosis
- expansive
- can be bubbly
- can have int calc
- can have soft tissue component
- may be surrounding raction
- can have 2ndry ABC
MR
non spec
T1 hypo to iso
T2 iso to hypo
C+ avid
ddx
- osteoid osteoma (smaller)
- ABC
- GCT
- osteosarc
Osteochondromas are and path
benign one tumours. low malignant potential.
develop during childhood and remain for life.
typically sporadic, or
- hereditary multiple exostoses (diaphyseal aclasis)
- trevor disease (dysplasia epiphysealis hemimelica
considered a chondroid neoplasm, primarily part of growth plate which separates and grows away from a nearby joint. medullary continuity. hyaline cartlage caps. malignant transformation in cartialge cap, unlike in single sporadic
lcaotions
- lower limb
- upper limb
- spine
Osteochondroma features assoc with sarcomatous transformation
GLAD PAST
Growth after maturity
Lucency (new)
Add scinitigraphic activity
Destruction
Pain after puberty
and
Soft tissue mass
Thickened cap >1.5cm
Hereditary multiple exostoses path
autosomal dominant inheritance. rare. can rarely be assoc with enchondromatosis, known as metachondromatosis.
EXT1, EXT2 or EXT 3 genes on 8q24, 11p11-13 and 19p respectively
Trevor disease is
extremely rare non hered disease characterised by osteochondromas arising from the epiphyses.
classification:
Classic
- hemimelic, more than one bone in single lower extremityy
Localised
- single bone unilateral or bilateral
generalised
- invovling whole limb from pevlis to foot
Primary synovial chondromatosis is and path
benign monoarticular disorder of unknown origin, cahracterised by synovial metaplasia and proliferation resulting in intraarticular cartilaginous loose bodies or similar size. can be ossified.
self limiting benign neoplastic process. proliferative chondroid nodules of the synovium. three phases
- initial; metaplastic formation of nodules
- transitional; detachement and loose bodies
- inactive; resolution of synovial proliferation, bodies may increase in size
Primary synovial chondromatosis imaging
XR
- depends on degree of ossification
- most often multiple and unifrom in size
MR
depends on preponderance on synovial prolief, LB formation and extent of calcification
typically chondroid signal
T1 inter
T2 high
can otherwise by fully ossified
ddx
secondary chondromatosis
- older, degen, fewer and larger fragments
tenosynovial GCT
- more confluent masses
- diffuse low intensity
synovial haemangioma
lipoma arborescends
siderotic synovitis
tumeral calcification
periarticular melorheaostosis
Secondary chondromatosis is and imaging
disorder that denotes intraarticular loose bodies secondary to joint pathology such as trauma OA infection or neuropathic osteoarthropathy
fragments of bone, cartilage, or mixed. can enlarge if nourished by synovium
imaging
- usually larger, fewer and variable in shape than primary
- evidence of nearby joint pathology
Talonavicular coalition imaging
uncommon
mushroom sign (looks like a mushroom)
Hereditary multiple exostoses is
aka diaphyseal aclasis. autosomal dominant, characterised by multiple osteochondromas
EXT1, 2 or 3 gene, chromosome 8q24, 11p11-13 and 19p respectively
Osteosarcoma is and path
malignant bone forming tumours. second most common primary bone after MM. can be primary or secondary, with diff histo types.
Assoc
- pagets
- irradiation
- retinoblastoma
- rothmund thomson syndrome
- fibrous dysplasia
- mazabraud
location
Primary
- typically metadispahysis of long bones in appendicular
- other; fibula, innominate bone, mandible (gnathic), maxilla, vertebrae
Secondary
- much wider, mirroring combined incidence of their underlying conditions
Can be classified by relationship to bone:
- intramedullary/central 80%
- surface 10-15%
- intracortical (rare)
- extraskeletal (5%)
Classification
Primary
- intramedullary
= conventional
= low grade central
= telengiectatic
= small cell
- surface
= parosteal
= periosteal
= high grade surface
Secondary
Path
- bulky heterogenous tumours
- haemorrhage, fibrosis and xcystic
- bone formation characteristic
- poorly formed trabecular bone with cellular pleomorphism and mitoses
- ALP may be raised
Conventional osteosarcoma imaging
XR
- medullary and cortical destruction
- wide zone of stransition
- permeative or moth eaten
- agg periosteal rxn
- soft tissue mass
- tumour matrix/ossification
- ossified mets
MR
- can cross epiphysis so look for that
- look for extent
T1
- soft tissue; intermediate
- ossified’; low
- peritumural oedema;’ intermediate
- scattered haemorrhage;’ varoiable
- solid bits enhance
T2
- soft tissue; high
- ossified; low
- peritumoural oedema
ddx
- infection
- mets
- ewings
- abc
Parosteal ostesarcoma is and imaging
subtype of osteosarc. arises from outer layer periosteam. most common juxtacortical or surface osteosarc. can progress to high grade.
composed of dense osteoid compoonent attached to outer cortex over narrow zone. originates from outer fibrous layer of the periosteam. extensive bone matrix and minimal fibroblastic atypia
immunohistochem; reactive to MDM2, CDK4
Imaging
XR
- usually metaphysis
- most commonly posterior distal femur, then tib, then humerus
- large lobulated exophytic cauliflower like mass with central dense ossification
- string sign; thin radiolucent line separating tumour from cortex
- tumour stalk; grows within tumour, obliterates radiolucent line
- cortical thickening without periosteal reaction
- tumour extension into medullary cavity
MR
- low on T1 and T2
- high t2 suggests higher grade
Periosteal osteosarcoma is and imaging
second most common surface osteosarc. arise from inner germinative layer of the perioosteum. higher grade than parosteal and lower than conventional. predominantly chondroid matrix
location
- diaphyseal
- femur and tibia
- arises from cortex, atttached at origin.
- intramedullary extension is rare
XR
- broad based surface soft tissue mass
- extrinsic erosion of thickened underlying cortex
- perpindicular periosteal reaction extending into soft tissue component
- rxn; sunburst or codmans
MR
- low on T1 and T2, may see bony spicules radiating from the surface lesion
- may be huper on T2 which represents its chondroid matrix
- reactive marrow seen, but marrow invasion is rare
difficult to diff from conventional. conventional invovle entire circumfrence of bone and show intramedullary extension
Telengiectatic osteosarcoma is and imaging
uncommon variant of central osteasarcoma. characterised by empty or blood filled cystic spaces separated by septa comprising >90% of the lesion
Location
- metaphysis of long bones, with extension into epiphysis or diaphysis
- dist femur>tibia>humerus>prox femur
- rare; fibula, skull and ribs, pelvis
XR
- expansile lytic bone lesion at metaphysis
- geographic bony destruction with a wide zone of transition
- less osteoid matrix than conventional
CT
- low atten FF levels
- thick peripheral and nodular septal enhancement
- osteoid matrix mineralisation
MR
- fluid fluid levels
- soft tissue componenent
- often heterogenosu
- enhancement of septa with nodularitty and sofgty tissue component
- hamoeerhage
ddx
- ABC/GCT; no soft tissue component, narrower zone
Extraskeletal osteosarcoma is and imaging
rare mesenchymal tumour in the retroperitoneum and soft tissue of extremities without any bone attachement
subtype of osteosarc. usually middle ages. radiation risk factor.
well defined lesion with haemorrhagic and necrotic areas. high grade spindle cell malignancy with osteoid and chondroid matrix. resembles MFH, osteoblastic osteosarc and chondroblastic osteosarc
location
- lower extremity
- upper extremity
- retroperiotneum
- trunk
Imaing
XR
- soft tissue density with variable calcification
CT
- tumour with pseudocapsule
- calcification
- extensive central mineralisation and lack of peripheral well defined ossification distinguishes it from myositis ossificatns
- heterogenous post contrast enhancement
MR
- well circumscibred heterogenous mass with hameotrhage and necrosis
- t1 iso
- t2 hyper
Gnathic osteosarcoma is and imaging
subtype of osteosarc in th mandible, maxilla
can be osteoblastic, fibroblastic or chondroblastic
imaging
OPG
- garrington sign (thickening of the periodontal ligament/membrane space of invovlet teeth in the setting of gnatic osteosarc)
CT
- cortical invoement
- soft tissue extension
- intramedulalry bone extensio
- matrix calc
Rhabdomyosarcoma is and assoc
malignant tumour with skeletal muscle cell morphology. most common soft tissue tumour in children. generally young patients, slight male.
assoc
- nf1
- bws
- li fraumeni
- dicer 1
- costello syndrome
path
- differentiate into tumour resembling skeletal muscle rather than arising from
three subtypes
- embronal (spindle/botyroid/anasplatic)
- alveolar
- pleormorphic
Location
- head and neck (orbit, oro/nasopharynx, sinuses)
- genitourinary (paratest, bladder)
- other (trunk, gi tract)
imaging
- non spec, indistinguishable from other sarcomas
- in extremities, embryonal can cause bowering (suggest slow growth)
- haemorrhage common in alveolar and pleomorphic, heterogenosus with necrosis
- embryonal more homogenesis
Ewing sarcoma is and path
second most common primary bone tumour of childhood. typically children and adolescents.
path
- small round blue cell tumour
- regular sized primitive appearing cells.
- closely related to soft tissue tumours pnet, askin, neuroepithelioma (ewings fam)
- non random t(11,22)(q24:q12) chromosome rearrangement
location
- lower limbs
- pelvis
- upper limb
- spine and ribs
- skull and face
almost always metadiaphyseal or diaphyseal
GCT of bone is and path
locally aggressive and rarely malignant bony neoplasm. end of long bones. occur when growth plates are closed, typically early adulthood.
assoc
- pagets
- gorlin goltz
- jaffe campannuci
path
- locally aggressive and rarely metastasising
- eccentrically at ends of long bones
- thorught to arise from metaphyseal side of growth plates
- neoplastic mononuclear stromal cells and non neoplastic osteoclast like giant cells
- over expression in RANK RANKL by neoplastic mononuclear stromal cells signallying pathway with resulting hyperproliferation of osteoclasts
micro
- non neoplasti giant cells with neoplastic mononuclear cells between
- mitoses, atypical sugg malig
- haemorrhage, naeurysm, foamy macorcphages and haemidesiden depositon
immunopheno; h3.3-g34w
gene; h3-3a(h3f3a)
location
- eccentric, end of long bone
- distal femur
- prox tibia
- distal radius
- prox humerus
- sacrum
- vert bodies
- can be hands, feet, innominate bones
Tenosynovial gct is and path and imaging
aka gct of tenddon sheaths. fibrohistiocytic tumours. usually benign. arise from synovium of joitns, bursae or tendons. synovial diff. can be localised or diffuse.
previously known as PVNTS. PVNS/PVNTS no longer recommnded.
unknown aetiology. can be localised or diffuse, intra or extraarticular.
micro; varying mononuclear cells, multinucleated fiant cells, foamy macrophages, inflammatory cells, haemosiderin deposition and stromal collagenisation.
csf1 translocation
localised
- most common in the fingers
- then wrist, ankle, foot, knee
- can be extra or intra artic
diffuse
- monoarticular large joints. knee, hip
- then ankle, shoulder, elbow, facts, tmj
Aneurysmal bone cysts are and path
expansile osteoclastic giant cell rich bony neoplasms. composed of numerous blood filled channels and cystic spaces
path
- muliloculated blood filled spaces of variable size separated by fibrous septa. surrounded by thin reactive bone formation. rich in multinucleated osteoclast like giant cells
location
- eccentric metaphysis long bones
- adjacent to unfused growth plates
- long bones
- spine and pelvis
- short bones hands and feet (more central)
- craniofgacial
- epiphysis, epiphysis equiv or apophysis (rare but important)
do not express h3.3pgly34trp unlike giant cell tumours
cytogenitc rearrangments of the usp6 gene
Nodular fasciitis is and imaging
non neoplastic rapidly spreading soft tissue lesion in the deep subcut region or in the fascia
most commonly volar forearm, lower extre, chest and back
path poorly understoof; could be reactive in response to trauma, could be chromosomal abnorm sugg neoplastic
can be subcut, facial or intramuscular. benign prolief of fibroblasts and myofibroblasts. rapid growth, abundant spindle shaped cells and mitotic activity.
imaging
US
- one or more well defined iso to hypo nodules with mildly increased vascular flow
MR
- can be myxoid, cellular or fibrous
- this accounts for variable intensity
ddx
- dupuytrens disease
- extraabdominal desmoid
- neurofibroma
- fibrous histiocytoma
- soft tissue sarcoma
- early MO
Chondromyxoid fibroma is and imaging
rare benign cartilaginous neoplasms.
typically younger adults but varies. progressive pain/swelling
variable chondroid, myxoid and fibrous tissue. pseudolobulated architecture.
located in metaphyseal regions of long bones. may extend to epiphyseal line. classic upper third of the tibia. can be small bones foot, distal fgemur, pevlis
imaging
XR
- lobulated or oval eccentric lytic lesion
- well defined sclerotic margin
- expansile
- parallel to bone
- geographic bone destriction
- no periosteal rexn
- presence of septations
- internal matrix
- perilesional scelrotisis
MR
- T1 low
- peripheral nodular enhancement, can be more diffuse
- t2 inter to high
ddx
- abc
- gct
- nof (younger)
- chondroblastoma (younger)
Chondroblastoma is and imaging
benign chondrogentic bone neoplasms. epip[hysius or apophysis in young patients
well defined tumours of chondroblastic cells, islands of chondroid matric with sclerotic rim. usually eccentric position in epiphysis and apophysis of long bones
imaging
XR
- radiolucent
- internal fluffy calcs
- narrow transition
- bone mieralisation
- endosteal scalloping, cortical thinning, erosion
- expansile remodelling
- rarely cortical breaches with soft tissue
- can have periosteal rex
- can have effusion
MR
- lobular internal architecture
- thin sclerotic rim
- surrounding oedema
- cortical invovetn
- soft tissue oedema
- T1; inter
- T2; variable, heterogenous inter
- STIR; high
C+ heteorgenous moderate, with surrounding marrow/soft tissue enhancement
ddx
- clear cell chondrosarcoma
- osteomyelitis
- intraosseous ganglion
- giant cell tumour (closed physis)
- abc
- CMF
- EG
Chordoma is and path
uncommon malignnt tumours of the axial sckeleton
arising from embyronic remannts of the primitive notochord, rathkes pouch to coccyx
locally aggressive, uncommon mets
path
- firm masses
- fluid and gelatinous substance, and necrotic areas
- physaliphorous cells
- three subtypes; conventional, chondroid, poorly/dediff
- genetics; tbxt duplication, pik3ca signallming mutation, lyst mutation, smarcb1 deletion
location
- sacrococcygeal
- sphenooccipital
- vertebral bone; cervical, lumbar, thoracic
Chodroma imaging
CT
- centrally
- well circum
- destrictive lytivc
- expansile soft tissue mass
- irregular intratumral calc
- enhancing
MR
T1
- inter to low
- small foci haemorrhage
T2
- high
C+
- hetregenous, honeycbomb arreapnce
SWI; variable blooming
DWI; variable
DDX
clival
- chondrosarc
- plasmacytoma
- meningioma
- macroadeonoma
- ecchordosis physaliphora
- benign notochodral cell tumour
Vert
- chondrosarc
- giant cell
- spinal mets
- plasma cystoma
- lymphoma
Aggressive fibromatosis is and path
type of msk fibromatosis. non met but neoplastic. like desmoids of the abdomen (extra abd desmoid).
assoc
- trauma
- preg
- oesotrogen
- gardners
- fap
path
- non encap, poorly circumscribed, infiltrative
- insidious and invasive
- looks like scar tissue, fibroblasts embeded in abundant collagenous matric with increased cells at the periphery
location; superficial or deep soft tissues, anywhere. head and neck most common
MSK fibromatosis classification
Superficial
Adult
- palmar (dupuytrens)
- plantar (ledderhose)
- knuckle pads
Children
- calcifying aponeurotic fibroma
- lipofibromatosis
- infantile difitial fibroma
- inclusion body
Deep
Adults
- desmoid; intraadomina, abdominal wall, extraabdomainal (breast, aggressive)
Children
- fibromatosis colli
- myogirboma
- myofibromatosis
Solitary fibrous tumour is and path
rare neoplasm of mesenchymal origin. can be anywhere, characteristically; dura, liver, orbit, pleura, spinal cord
used to be hamengiopericytoma
mass effect. can have hypoglycaemia (doege potter syndrome) from IGF2 secretion
location
- pleura most common
- solid organs
- abdominal cavity
- extremities/trunk
- head and neck incl orbit
multilobulated firm masses. can have fat, haemorrhage, nrcosis
collagenous matric with arrays of spindle cells. necrosis, cyts, mycoid, calc and haemorrhage., vasculaity, atrypica or malignancy. staghorn blood vessels.
genomic inversion 12q13 locus, fusion of nab2 and stat6 genes
immunohisto
- stat6
- cd34
- cd99
- bcl2
- vimentin
- cytokeratin, s100, p53
cartilage interface sign
rotator cuff tear
increased through transmission shows interface of hyaline cartilage and cortex
creates a double line parallel under tear
osteopetrosis aut recess key features
oraganomeagly
anaemia
infantile and lethal
osteopetrosis aut recess key features
oraganomeagly
anaemia
infantile and lethalsa
sagging peribursal fat
rotator cuff tear
hawkins sign
talus dome subchondral lucency after talar neck fracture
indicates viability
Dense transverse metaphyseal bands ddx
PRINCES
Poisoning (lead, mercury)
Rickets
Infection (TORCH) Idiopathic hypercalc
Normal variant, neoplastic (leukaemia, lymphoma)
Congenital syphillis
Endocrine (congen hypothyr)
Sick cell, scurvy
