MSK Flashcards
Crescent sign
Osteonecrosis
FICAT staging of AVN
I - normal XR, abnormal line of demarcation on MRI
II - trabecular changes, patchy sclerosis and lucency
III - segmental flattening
IV - secondary OA
SLAP lesion
Dx criteria
labral tear
superior labrum anterior - posterior to biceps anchor
High SI perpendicular to biceps tendon ( normal sublabral sulcus is parallel to biceps anchor)
Linear high signal which extends posterior to labrum.
ABCDES approach to joints
Alignment Bone density Cartilage/joint space Distribution Erosion Soft tissues
Psoriatic arthritis
RF
Pencil in cup / IP jt erosions (fuzzy) Periostitis/new bone form Distal predominance Telescoping Ivory phalanx Soft tissue swelling- sausage digit Sacroiliitis/ankylosis Asymmetrical paravertebral ossification, bulky, non marginal
Arthritis with preserved joint space 3
Synovial osteochondromatosis
PVNS
TB - Phemisters triad
Phemister triad in TB joint involvement
PEriarticular osteopenia
Marginal erosions
Gradual narrowing of jt space
Ossification of the PLL
Idiopathic Men C -S Myolpathy DISH
DISH
flowing ossification > 4 levels
normal disc height
SI joints normal
….Extensive osteophytosis without disc narrowing or sclerosis
Pagets disease
3 Phases
Buzzwords
Complications
Lytic - flame/lytic with non sclerotic/ blade of grass
Mixed - trabecular coarsening, osseous expansion, cortical thickening
Sclerotic - ivory vert.
Picture frame
Oste. circumscripta
Cotton wool skull
Complications: Bowing Fractures Neurologic compromise Sarcomatous transformation
SLE arthritis
RF
6
non sp ST swelling Non erosive Reducible subluxation (3-8%) - ulnar dev Calcification Osteoporosis Acrosclerosis/osteolysis
Arthritis with normal joint space
Gout
PVNS
Primary synovial osteochondromatosis
SLE
Arthritis with uniform jt space narrowing
Inflammatory
Infection
Arthritis with non uniform narrowing
OA
Neuropathic
CPPD
SLAC Wrist
Scapholunate advanced collapse Widening of scapholunate articulation ( Terry Thomas) Capitate migration down SL tears Common with CPPD, RA, drilling
Lytic lesions in posterior elements of spine
GO APE
GCT OSteoblastoma ABC Plasmacytoma EG
Radiographic changes of acute pyogenic osteomyelitis
Acute
7-10d
2-4w
6-8w
Acute (24-48hrs) : ST swelling, loss of fat plane
7-10 days : intramedullary destruction
2-4 weeks : cortical destruction, endosteal scalloping, periosteal reaction
6-8 weeks : sequestrum, involucrum (reactive new bone beneath elevated periosteum)
Sclerosing osteomyelitis
Osteomyelitis of Garre
Subacute form
Extensive diaphyseal sclerotic lesions
Septic arthritis
MRI findings
6
Joint effusion Soft tissue oedema Synovial CE Uniform jt space narrowing Erosions Bone marrow oedema
Sickle cell osteomyelitis
Salmonella, staph
Diaphyseal
Frequent in areas of infarction
Syphilis
Wimberger’s sign
Symmetric lytic lesions medial metaphyses of proximal tibia
Periostitis
Saber shin deformity ( anterior bowing)
Gummas ( sterile bone abscesses; mixed skull lesions)
Rubella
XR findings
Medial metaphyseal beaking
Irregular metaphyses with celery stalking
DDx : toxo,CMV
Hypoparathyroidism
RF
OSteosclerosis
Soft tissue Ca : subcut, BG
Hypothyroidism
RF
Delayed skeletal maturation
Wormian bones
Epiphyseal dysgenesis : stippled, coned, fragmented
RF thyroid acropachy
usually post Rx
fluffy symm periostitis
Soft tissue swelling
Scurvy signs
Wimbergers ring at epiphyses
White line of Frankel of metaphysis
Metaphyseal corner # or spur ( Pelkens spur)
Arthropathy affecting hands/wrists
DISTAL
3
Psoriasis
Reiters
OA
Arthropathy affecting hands/wrists
Proximal
2
RA
CPPD
Diseases that cause subchondral cysts GEODES
4
RA
DJD
CPPD
AVN
Causes of high riding shoulder
3
CPPD
RA
Rotator cuff tear
Asymmetric non marginal syndesmophytes
2
Psoriasis
Reiters
Erosions with sclerotic margins
1
Gout
Gout
punched out Erosions Mouse bite erosions juxta articular Sharply marginated overhanging edge Preserved joint space Asymm polyart distri normal mineralisation ST masses
Cause of pseudo charcot joint
1
CPPD
Associations of CPPD
3
Primary HPT
Gout
Haemachromatosis
Scleroderma/dermatomyo
RF
4
Soft tissue calcification
Soft tissue wasting
Osteoporosis
Acro osteolysis
CPPD
RF
Chondrocalcinosis
Patellofemoral comp
Pseudogout arthropathy : medial jt sp narrowing, subchond sclerosis
, osteophyte formation.
Haemachromatosis
RF
Assoc
Severe jt space narrowing mainly MCP
Sclerosis
minimal chondrocal
Assoc with CPPD 50%
Charcot
6D
Density ( sclero/paenia) Destruction Debris Distension Disorganisation Dislocation (heterotopic new bone)
JIA
2
overgrowth epiphyses
Gracile diaphyses
Apple core appearance of femoral neck
2
Synovial (osteo)chondromatosis
PVNS
Friebergs infraction
AVN of second MT head
flattening, collapse, sclerosis
can also involve 3/4th MT heads
compensatory hypertrophy of cortex
Keinbochs
lunatomalacia
AVN of lunate
Kohlers
tarsonavicular AVN
Haglunds Xd
retrocalcaneal bursitis
– > extensive erosive changes posterosup aspect of calcaneus
new bone,
soft tissue mass
Ankylosing spondylitis
HIP/pelvis
5
concentric jt space narrowing articular erosions fluffy enthesopathy fused SIJ protrusio acetabuli
Haemachromatosis
Demo
RF
30-50 yr, rare, delayed dx Arthritis/joint pain presenting Early OA without trauma : MCP, ankle, wrist FHx positive Do Serum Fe/transferin sat ratio >45%
Milwaukee shoulder
Older women Huge effusion Arthritis Crystal ( HADD) rotator cuff tear
fluid vs synovitis
Anechoic fluid
compressible fluid
no hyperaemia fluid
Synovitis - non compressible, hyperaemia.
Intra articular Gout USS
monosodium urate
neg birefringence
joint effusion - tiny hyperechoic foci cartilage icing - double contour sign ( cf CPPD mid cartilage) Synovitis Erosions
Tophi appearance
USS
MRI
USS: hyperechoic, heterogeneous with hypoecho rim,
wet clump of sugar
variable shadowing
MRI
T 1 low /iso
T2 hetero
CE hetero
