Module 2: MSK Flashcards
stress fracture is
abnormal stress on normal bone
insufficiency fracture is ..
normal stress on abnormal bone
bones heal in how many weeks
6-8 ; tibia longest, phalanxes shortest
Most often scaphoid fracture
waist 70%
thenproximal 20%
then distal 10%
first sign of AVN for scahpod fracutre
sclerosis
why does sclerosis signify AVN in scaphoid
dead bone can’t turnover
location of fracture most at risk of aVN in scaphoid
proximal
Scaphoid fracture on MRI look for what
Dark on T1; high STIR/T2, LOW T1
What is a SLAC wrist?
Complication of what aetiology?
What ligament is injured?
complication of trauma
Scapho-lunate advanced collapse
injury to SL ligament
what is SNAC wrist
Scaphoid non-union advanced collapse
a potential complication of trauma as well
Scaphoid non-union advanced collapse
happens with injury to the scaphoid
which way does the scahpoid want to be rotating
what holds it back
Wants to rotate volar in flexion
SL ligament holds it back
if SL breaks what happens to the capitate?
the scaphoid radial distance narrows
the capitate moves proximally.
how can you treat a SLAC wrist?
wrist fusion - max strength loss of motion
proximal row carpectomy - max rom, lose strength
describe a perilunate dislocation
capitate moved off the back (sits perilunate); capitate moves dorsally
Pencil out of cup;
Associated in 60% cases = scaphoid #
describe a midcarpal dislocation; what is associated #; what is associated ligament injury?
lunate is dislocated anteriorly and capitate posteriorly;
Pencil and cup move are both dislocated in opposite directions;
Triquetral fracture; Triuetro-lunate ligament disruption
describe a lunate dislocation
lunate rotate and dislocated anteriorly.
Lunate moves volar;
Dorsal radiolunate ligament injury.
Normal Scaphlunate distance
3mm
the lunate wants to move in which direction ?
rock posteriorly; dorsally
what does DISI stand for
“Dorsiflexion instability”
dorsal intercalated segmental instability
Post-radial sided injury
Scapholunate ligament injury
VISI stands for
volar intercalated segmental instability
What happens in DISI ?
rocking dorsally of the lunate
happens due to an injury of the SL ligament. (therefore a radial sided injury)
What happens in VISI?
very rare
ulnar sided injury will damage the lunotriquetral ligament. Lunate is no longer pinned.
Lunate will tilt volar direcitons.
what is the normal scaphoid lunate angle?
30 - 60 degrees
DISI vs VISI angles ?
DISI - opens the angle- greater than 60
VISI - closes into a V - less than 30
Bennett and rolando fractures - whats the difference
Rolando is comminuted
in a bennet fracture, what tendon attachement causes the dorsolateral dislocation
abductor pollicis longus
What is gamekeepers thumb?
base of the proximal phalanx of the thumb
ulnar collateral ligament disruption
What is a stener lesion
in gamekeepers thumb.
adductor tendons get caught in the torn edges of the Ulnar collateral ligament (which has been broken off)
yo yo appearance on MRI
What is carpal tunnel syndrome.
hwo does it appear on US (nerve; wasting; bowing)
Median nerve: swollen or looks smashed/flattened. Increased signal on MRI.
The eminence wasting
Bowing flexor retinaculum
what treatment is assocaited with carpal tunnel syndrome
3 other associations
Ax with dialysis
- pregnancy; hypothyroidism; DM
What is Guyon’s canal syndrome/
Ulnar nerve entrapment
Formed by pisiform and hamate.
Cycling “handle bar palsy”
guyons canal is made by what bones
hamate hook
pisiform
fracture of the radial head with anterior dislocation of the DISTAL radial ulnar joint is called
Essex Lopresti
Ulnar fracture and radial head dislocation is called
Monteggia
distal 1/3 radial shaft fracture with an associated distal radioulnar joint (DRUJ) injury.
.Galleazzi
cubital tunnel syndrome occurs due to
repetitive valgus stress
compression from tumour, haematoma et
accessory muscle compression
- anconeus epitrochlearis
Hill Sachs lesion is on the
Humerus
posterolateral
Bankart lesion is on the
glenoid
Hill sachs occurs where on the humers?
postero lateral
Hill Sachs best seen on which radiograph view
internal rotation
Bankart lesions are found where on the glenoid
anterior inferior labrum
Bankart and Hill sachs happen in which type of dislocation
anterior
inferior dislocation of the shoulder causes what damage
to the axillary nerve
trough sign
happens in posterior dislocation
injury to the anterior humeral had impaction
shoulder prosthesis depends on what?
is the cuff intact
is the glenoid intact
If the glenoid is intact what are the options
Cuff intact
- resurfacing/Hemi
Cuff buggered
- Hemi or reverse
If glenoid is buggered
Cuff intact
- TSA
Cuff buggered
- reverse
What is the most common shoulder prosthesis complication?
loosening of the glenoid component
Post-shoulder surgery: what is anterior escape?; what tendon fails?
subscapularis fails, whole humeral head migrates anteriorly
femoral nek fractures
medial are what type
stress fracture
femoral neck fractures
lateral are what type
bisphosphonate related fractures
hip dislocoation
which direction is most common
posterior
femur fracture at risk of AVN is what
displaced intracapuslar fracture
snapping syndrome what are the three types?
External
internal
intra-articular
External snapping syndrome
Iliotibial band or gluteus maximus over greater trochanter
internal snapping syndrome
Iliopsoas over iliopectineal eminence/femoral head
intra-articular snapping syndrome
labrel tares
what are the two types of femoroacetabular impingmenT?
CAM
PINCER
CAM
young men
anterior superior femoral neck protrusion.
pistol grip deformity
Pincer impingment
middle aged women
over coverage of the femoral head by the acetabulum
most common location for an acetabular labral tear?
anterior superior
what are the 5 testable pathologies of the sacrum?
SI degenerative change
unilateral SI infection
chordoma
sacral agenesis
insufficiency fracture
sacral insuffiicency fracture most common in what demographic; and condition.
What are three other common causes?
postmenopausal women with osteoporosis
also in RA, pelvic radiation, steroid use
Honda sign on nuclear medicine
Sacral insufficienc signs
Knee
what is a segond fracture?
What tears?
Fracture of the lateral tibial plateau
Ax with ACL tear in 75%
occurs with internal rotation
what is a reverse Segond fracture;
Associated ligament(s)
medial tibial plateau fracture
PCL and medial meniscus injury is ax
external rotation
fibula - what is the arcuate sign? ; what ligament?
avulasion of the proximal fibula
90% ax with PCL injury
what is the deep intercondylar notch sign
depression of the lateral femoral condyle (terminal sulcus) that occurs secondary to an impaction injury.
This is ax with ACL tears
Patella dislocated in which direction?
lateral
which ligament is damaged with lateral patella dislocaiton
medial patello femoral ligament
What is patella alta
high ridingin patella
(can be from old patella ligament injury)
what is patella baja
low riding patella
quadriceps injury
tibial platea fracture - which side is more common to injury?
lateral plateau
Schatzker classificaiton - type 2 most common
split and depressed
Pilon fracture - what is it
tibial plafond fracture
impaction
75% will have fracture of distal fibula
Tillaux fractures is what slater harris
slater harris 3
anterlateralaspect of the distal tibial epiphyis
Triplane fracture is SH calssifciaton of what
4.
vertical component through the epiphysis
horizontal through the component of the physis.
oblique through the metaphyiss
Maisonneuve fracture
what is it
unstable fracture
medial tibial malleolous
disruption of the distal tibiofibular syndesmosis.
PROXIMAL fibula fracture
does NOT extend into the hindfoot
What is a casanova fracture?
axial loading pattern for burst lumbar fracture
in the context of bilateral calcaneal fractures.
what angle of bohlers is concerning
less than 20
what is a jones fracture?
fracture at the base of the 5th metatarsal.
base of 5th avulsion fracture is pulling fromwhat muscle
lateral cord of the plantar aponeurosis or peroneus brevis
Should you be concerned about a 5th metatarsal stress fracture
yes
hard to heal
LisFranc injury.
What does the Lisfranc ligament connect?
Homolateral vs divergent
lisfranc ligament connects medial cuneiform to 2nd metatarsal base plantar side.
Get homolateral and divergent pattern
Lisfranc injkury cant be excluded on q
non weight bearing images
Lisfranc injury ax pattern
base of 2nd metatarasal
Compressive patterns of fracture do….
well
Fractures on the tensile side….
do badly
what does SONK stand for
Spontaenous Osteonecrosis of the knee
SONK > AKA?
Laterality?
Ax with what ST injury?
Subchondral insufficiency fracture
unilateral
ax with meniscal injur y
Navicular stress fractures affect who?
runners on hard surfaces
high risk of AVN
March fracture is seen in the
metatarsals
common
what is a calcaneal stress fracture?
fracture of the bone.
fracture line will be perpendicular to the trabeculae
Where are the foot high risk fractures?
Sesamoid great toe
tarsal naviuclar
talus
5th metatarsal
what are the leg high risk fractures
femoral neck with tensile side
transverse patellar fracture
anterior tibial fracture (midshaft)
What is meatn by osteopenia?
lucent bones
What is osteomalacia?
- aetiology (x3)
- radiographic features?
- aetiology : vitamin D deficiency ; phosphate deficiency ; decreased deposition in bone
- diffuse demineralization; blurred trabeculae ; poor corticomedullary differentiation ; looser zones (insufficiency fractures)
Features of osteomalacia
Ill defined travbeculae
ill defined corticomeduallary junction
bowing
loosers zones
What are loosers zones
wide lucent bands
right angle to the cortex
think osteomalacia
type of insufficiency fracture
what is osteoporosis?
low bone density
normal ratio
<-2.5
what are the imaging features of osteoporosis ?
thin sharp cortex
prominent trabecular bars
lucent metaphyseal bands
spotty lucencies
DEXA - what is the T score
Density relative to young adult
T score >-1
normal
T score <-1 to <-2.5
osteopenia
T score <-2.5
osteoporosis
Z score is what?
density relative to aged match control
Za Zame age
DEXA - things to cause a false negative?
excessive osteophytes
dermal calc
metal
compresson fractures
What is reflex sympathetic dystrophy?
occurs after over active sympathetic system
eg after trauma or infeciton
what does reflex sympathetic dystrophy look like? [complex regional pain syndrome]
unilateral RA with preserved joint spaces
3 phase hot bone scan
vascular synovial membrane
What are the two types of transient osteoporosis ?
What are radiographic findings?
What are the MRI findings?
What are the bone scintigraphy findings?
- Of the hip (classically described in pregnancy, but actually more common in middle aged men); Regional migratory osteoporosis
- Subchondral cortical loss, often profound osteopaenia, PRESERVED joint space.
- Follows bone oedema
- Markedly increased uptake.
Transient osteoporosis of the hip
affects who i
pregnant patient, can be men too
normal joint spaces
resolves
Regional migratory osteoporosis is what?
idiopathic disorder
pain in a joint but moves to different joints
Osteoporotic compression fracture on MRI on t1
Band like fracture line dark on T1
Spinal mets, when will collapse happen
once invaded whole vertebral body
think of this if invading posterior margin
What is osteochondritis dissecans (OCD) ?
Asecptic seperation of an osteochondral fragment
lead to fragmentation and OA
Classic location of the osteochondral injury?
femoral condyle
knee
patella
talus
capitellum
Osteochondral injury/defect number of stages?
4
Stage 1 osteochondral injury.
Stable, covered intact
- injury limited to articular cartilage
- MRI findings: subchondral oedema
- x-ray findings: none
Stage 4 osteochondral injury
- osteochondral fragment displaced
- usually joint effusion present, surrounding fragment and filling donor site
- x-ray findings: increased lucency between osteochondral fragment and remainder of the bone, or loose body with donor site irregularity
How can you call an OCD fragment unstable?
on MRI
if there is T2 signal undercutting it
[high signal line (rim sign) demarcating fragment from bone usually indicates an unstable lesion, however, false positives can result from oedema]
What are osteochondroses?
normally in kids
involve epiphyses [e.g. kienbocks; friebergs]
collapse, sclerosis, fragmentation
Kohlers osteochondritis - where and who>?
tarsal navicular
male 4-6. no surgery
Freiberg osteochondritis - where adn who?
Second metatarsal head
teenage girls. leads to OA
Severs osteochondritis - where and who
Clacaneal apophysis
What is panners ostechondritis?
Demographic?
Capitellum
kid 5- 10
Perthes osteochondritis
femoral head
caucasion kid, 4- 8
Kienbock osteochondritis - where and who?
carpal lunate
20 - 40 year old.
negative ulnar variance
which tendons are affected in de Quervains?
APL and EPB
how many extensor compartments are there
6
What is in the carpal tunnel
FPL
median
8 digitorum superficial / profundus
what 4 bony bits give the carpal tunnel the roof?
hook of hamate
pisiform
scaphoid tubercle
trapezium tubercle
which spaces are used for wrist arthography?
pisiform recess and radiocarpal joint
they communicate
should glenohumeral and subacromial bursa communicate
no
implies full thickness rotator tear
Ankle joint and common peroneal tendon sheath
do they communicate?
no
implies calcaneofibular ligament tear
Do the achilles tednon and posterior subtalar joint communicate?
No . Never
Triangular fibrocartilage tear: features on MRI. Acute injury, young person
- Fluid-intensity signal extending to the surface or along the medial aspect of the ulna
- Usually associated with distal radioulnar joint (DRUJ) effusions (however, these are non-specific in isolation)
- Ulnar styloid process or foveal cystic change or bone marrow oedema
Scapholunate ligament tear has a sign called
most important band for stability
3mm is normal
Terry Thomas gap
dorsal band.
What is intersection syndrome?
Who does it most commonly affect?
Tenosynovitis of the radial wrist extensors.
Rowers.
intersection syndrome affects what compartment
First and second compartments ; extensor carpi radialis brevis and longus tenosynovitis
What are the two categories for tenosynovitis?
diffuse
focal
list two diffuse tenosynovities
nontuberculous mycobac infection
Rheumatoid arthritis
nontuberculous mycobac infection affects where
hand and wrist
affects those who are immunocompromised
describe types of focal tenosynovitis
overuse
infection - this is an emergency
isolate 6th flexor compartment tenosynovitis think
early RA
types of finger tip tumours
Glomus
Giant cell tumour of tendon sheath
Implantation Desmoid
Fibroma
What is a glomus tumour
benign vascular soft tissue mass.
T1 low
T2 bright
enhance avidly
Scallops
Giant cell tumour of tendon sheath 0 what is it?
PVNS of tendon
erosions on the underlying bone
T1 and T2 dark
blooms on gradient
Finger fibroma - what is it
benign overgrowth of tendon collagen
low T1 and T2. Will not bloom like GCT on gradient
cubital tunnel syndrome from repetitive what
valgus stress
Elbow T sign on MRI has damage to what
ulanr collateral ligament
throwers
How to differentiate
Panners (capitellum) osteochondritis from osteochondritis dissecanxs
Panner is 5-10 not teenager
Same MRI
No loose bodies in Panner. OCD is loose bodies
what is lateral epicondylitis
tennis elbow
extensor tendon injury
radial collateral ligament complex - tears due to varus stress
Medial epicondylitis affects
golfers
Golfers elbow is what pathology
common flexor origin. ulnar nerve may enlarge
epitrochlear lymphadenopathy
ax with
cat scratch
dialysis elbow is inflammation of what
olecronon bursitis
Two types of impingement are
external and internal
external impingment does what
impingement of rotator cuff overlying the bursal surface
what is the coracoacromial arch formed of
coracoid process
acromion
coracacromial ligament
Primary external impingement of the shoulder causes are considered due to an
abnormal coracoacromial arch
Types of primary external impingment (x3)
And what do they each impinge on?
Hooked acromion (“type 3”) - supraspinatus tendon
Subacromial osteophyte fomraiton - supraspinatus tendon
subcoracoid impingement - subscapularis
What muscle is most commonly impinged in subcoracoid impingement?
impinge subscapularis between coracoid process and lesser tuberosity
Secondary external causes (ie normal coracoacromiial arch)
Multidirectional glenohumeral instability.
- microtrauma from micro subluxation.
Internal causes of shoulder impingement refers to what process happening
impingement of rotator cuff on the under surface along the glenoid labarum and humeral head.
Internal impingement.
Posterior superior
- what are the details
In the exam, “internal impingement” most likely refers to this:
Postero superior rotator cuff involved. (supra and infraspinatus tendons)
Comes into contact with the psoterior superior glenoid.
Throwers shoulder
Internal impingement of the shoulder - Anterior superior - what are the details
What would be typical MRI findings?
horizontal adduction and internal rotation.
Here - undersurface of biceps and subscapularis tendon impinge against
anterior superior glenoid rim
KEY FINDINGS
articular-sided tears of the posterior supraspinatus and anterior infraspinatus tendons
posterosuperior labral tear or fraying or type IIB SLAP tear
humeral head cysts underlying the infraspinatus tendon
Subacromial impingment damages which tendon
supraspinatus
Subcoracoid impingment damages which
subscapularis
Posterior superior internal impingement damages what
infraspinatus;
[A little of supraspinatus]
which rotator muscle is most common to tear
supraspinatus
massive rotator cuff tear refers to
at least 2 of the 4 rotator cuff muscles torn
Should tendon tear: how to know its a full thickness tear
Gad in the bursa on MRI
high T2 signal in location of the tendon
Labrel tear favour which margin
superior
SLAP
labral tears track which direction
ant to posterior
is SLAP tear ax with instability
no
What is the SLAP mimic
sublabral recess
Labral tear mimic
sublabral foramen
- unattache dprotion from 1 to 3 o clock.
buford complex
- absent ant/sup labrum + thickened middle glenohumeral ligmanet
Bankart is caused by what dislocation
anterior
Types of bankart lesion
GLAD (Glenolabral articular disruption)
Perthes
ALPSA (Anterior Labral periosteal sleeve avulsion)
Bankart - cartilage
Bankart - osseous
GLAD stands for
How bad is it?
Glenolabral articular disruption
superfiicla partial labral injury, cartilage defect
Shoulder Perthes is what
detachement of the anteroinferior labrum with medially stripped but INTACT periosteum
ALPSA stands for what
Anterior labral periosteal sleeve avulsion
ALPSA causes what
Medially displaced labroligamentous complex with absence of the labrum on the glenoid rim. INTACT periosteum
True bankart is what
periosteum is disrupted.
often ax Hill Sach’s fracture
What is a HAGL? Shoulder injury.
non bankart lesion
Humeral Avulasion Glenohumeral Ligament
- avulsed inferior glenohumeral ligament.
from ant shoulder dislocation
Subscapularis attaches to what
lesser tuberosity
how can the biceps tendon sublux
normal fixed by some subscapularis transverse fibres
if damaged, can come out - MEDIAL dislocaiotn
how can the biceps tendon sublux
normal fixed by some subscapularis transverse fibres
if damaged, can come out - MEDIAL dislocaiotnw
what is quadrilateral space syndrome?
compression of axilary nerve in the quadrilateral space
- normally from fibrotic bands
borders of the quadrilateral space
Teres minor above
major below
Long head triceps diagnoal side
humerus other sided
what is parsonage - turner syndrome
muscles affected b pathology in two or more nerve distributions.
Conditon has idiopathic involvement of the brachial plexus
how many bundles does the ACL have
two
which acl bundle tightens the knee in flexion
long one
anteromedial
which acl bundle tightens the knee in extension
short
posterior lateral
medial meniscus is thicker…
posteriorly
knee meniscofmeoral ligaments that can mimic meniscal tears
Anterior and posterior meniscofemoral ligaments (Humphrey and wrisberg)
Humphry ligament is found
anterior knee
the knee conjoint tendon is formed by
biceps femoris and LCL
meniscal cysts are associated with what kind of injury?
horizontal cleavage tears
meniscocapsular seperation in the knee is associated with what injury
MCL injury.
weak inner layer, first to break
what is a bucket handle tear
usually medial meniscus
flips to lie anterior to the pcl looks like a double PCL
what is a meniscal ossicle?
focal ossification of the posterior horn of the medial mensicus, secondary to truam or development.
ax with radial root (of the meniscus) tears
what fracture is ax with acl tears
segond fracture
what is O’donaghues unhappy triad
acl tear
mcl tear
medial meniscal
Why is posterior lateral corner important of the knee
complex anatomy of IT band, LCL, biceps femoris and poplietus.
Missed PLC injury can cause ACL reconstruction failure
ACL reconstruction complications
roof impingement - need tibial tunnel to be in correct plain
maintaining isometry
arthrofibrosis - focal or diffuse. Cyclops lesion
Graft tear
what is ACL mucoid degeneration?
mimic acute or chronic acl tear.
no secondary signs o injury.
predisposes to ACL gnaglion cysts.
T2 celery stalks - striated high signal
T1 drumstick
patella dislocation - injury to which ligament?
medial patellar femoral ligament
what is the master knot of Henry in ankle anatomy
Dick crosses over Harry
FDL crosses over FHL at medial ankle
which ligament in the foot/ankle is the weakest?
Anterior talofibular ligament
(inversion injury)
What is posterior tibial tendon injury / dysfunction?
Acute pain at the navicular insertion.
Chronic will be tears at the medial malleolus.
results in progressive flat foot deformity
posterior tibial tendon injury / dysfunction
what happens to the hindfoot?
Valgus deformity
unopposed peroneal brevis action.
progression of posterior tibial tendon injury / dysfunction
PTT out, then spring ligament out
sinus tarsi jacked.
painful heel strike on a flat foot –> plantar fascitiis
what is a split peroneus breivs?
inversion injuries cause longitudinal splits in ligament
C shaped tendon
what is sinus tarsi syndrome?
between lateral talus and clacaneus
haemorrhage / inflammation of the synovial recess.
obliterated fat in the space is seen on MRI
what is tarsal tunnel syndrome?
tibial nerve compression.
pain in first 3 nerves
achilles rupture, loss of plantar flexion is lost unless….
Plantaris muscle is intact
Xanthoma sign in achilles
thickened
affects people with familial hypercholesterolemia
Morton’s neuroma MRI signal
Where do you find one?
Play with different signal characteristics, what is the differential?
Dark on all sequences without enhancement
Found between the third and fourth metatarsals 
Inter metatarsal bursitis : cystic with high T2 signal, and will extend ABOVE the transverse ligament 
Osteomyelitis in spine think
IV drug user
Osteomyelitis in Spine with kyphosis think
Gibbus deformity - TB
Stereotypical demographic of unilateral SI joint infection?
IV drug user (again)
Psoas muscle abscess think…
TB
What is a brodies abscess
chronic bone abscess
Name the four components for brodies abscess?
Outwards to inwards: cloaca; involucrum ; abscess ; sequestrum
what is sequestrum
necrotic bone surounded by granulation tissue
involucrum means
thick sheath of periosteal bone around equesterum
cloaca means
tract to where the dead bone lives
3 categories of acute bacterial osteomyelitis
hematogenous seeeding
contiguous spread
direct inoculation post operation
haematogenous spread of osteomyleitis ends up in…
the long bones, metaphysis
what are the MRI findings of osteomyeltiis
T1
- intermediate to low signal central component
- surrounding bone marrow of lower signal than normal due to oedema
- cortical bone destruction
T2
- bone marrow high signal
T1 C+ (Gd)
- post-contrast enhancement of bone marrow, abscess margins, periosteum, and adjacent soft tissue collections
Discitis source of infection in adults
recent surgery,orocedure or systemic infection
Discitis in children from
haematogenous spread
Spondylodiscitis signal on MRI
T1 : low signal in disc and in adjacent endplates
T2: high signal in disc and adjacent endplates and paraspinal soft tissues; LOSS of low cortex signal.
T1 C+ : enhancement of soft tissue, endplates, and periphery of abscess.
DWI : hyperintense in acute stage; hypointense in chronic stage.
What is Potts disease
TB of the spine
Potts disease (tuberculous spondylodiscitis) patterns on MRI (not signal).
spare the disc space
multi level thoracic skip involvement
Large paraspinal abscess
calcified psoas abscess
gibbusdeformity
What can mimic TB in the spine?
Brucellosis (unpasterized milk)
how quickly can septic arthritis destroy a joint
48 hours
Risk factors for necrotizing fasciits
HIV
transplant
diabetics
alcoholics
what bug causes nec fas
polymicrobial
or
group A strep
What is nec fasc called in the scrotum
Fournier Gangrene
what are rice bodies
Small loose intra-articular bodies seen on MRI that resemble rice grains
sloughed, infarcted synovium seen in end stage RA and TB infection of joints.
What is TB dactylitis?
kids more than adults.
short tubular bones of hands and feet.
periosteal reaction.
diaphyseal expansile lesion
what are the most common primary osseous malignancies?
myeloma / plasmacytoma
osteosarcoma
chondrosarcoma
Subtypes of osteosarcoma
conventional intramedullary
parosteal
periosteal
telanciectactic
feature of all osteasarcomas is that they produce
bone/osteoid from neoplastic cells
Conventional intramedullary osteosarcoma affects
who?
where?
Appearance of lesion ?
young (10-20)
femur
sunburst
codman triangle
lamellated
where does osteosarcoma met to
lungs
Type of lesions that risks of pathological fracture?
Lytic lesions
lesions over 3cm
lesions involving more than 50% of the cortex
Paraosteal ostesarcoma main features
size
marrow
grade
Bulky and big
marrow extension
low grade
Paraosteal osteosarcoma radiolucent line seperating bulky tumour from the cortex is called the
string sign
Periosteal osteosarcoma features
age
location
prognosis
worse prognosis than parosteal
(15-25)
occurs in diaphyseal regions like medial distal femur
telangiectatic osteosarcoma - main feautures on mRI
Fluid - fluid levels on MRI is classic.
High T1 from methemoglobin
what are the differentials for Fluid fluid levels in bones
Telangiectactic osteosarcoma
aneurysnal bone cyst
Giant cell tumour
Chondrosarcoma - main features
who
grade type
location
older adults
male more than female
mostly low grade
intramedullary or peripheral
risk factors for chondrosarcoma
pagets or anything affecting the cartilage
Permeative lesion in the diaphysis of a child - diagnosis is…
Ewings
What is a similar feature of ewings and osteosarcoma?
Ewings scleroses (bone only)
Osteosarcoma will lay down osteoid
can mimic
chordoma is seen in what age group
30 - 60
chordoma most common location is
sacrum
MRI feature of chordoma is that they are
very bright on T2
Midline bone tumour think… .
chordoma
List some aggressive soft tissue lesions
Fibrosarcoma
pleomorphic undifferentiated sarcoma
Synovial sarcoma
liposarcoma
Fibrosarcoma - on MRI they are
NOT T2 Bright (most other tumours are)V
Fibrosarcoma appear as
lytic
moth eaten / permeative
Pleomorphic undifferentiated sarcoma “PUS” / MFH (malignant fibrous histiocytoma) (same thing)
to note will look the same as
radiologically look the same sas fibrosarcoma
synovial sarcoma is seen where and what age group
lower extremities of those aged 20 - 40
mostly dont involve the joint
bunch of grapes sign?
synovial sarcoma
ball like tumour in the extremity of a young aduly think
synovial sarcoma
fatty mass in the retroperitoneum think
liposarcoma
liposarcoma affects what age group
middle aged
Myxoid liposarcoma MRI appearance
T2 bright but T1 dark
don’t mix with a cystic lesion
how to treat osteosarcoma
chemo then wide excisiton
how to treat ewings
chemo and radiation then wide excision
how to treat chondrosarcoma
wide excision
GCT how to treat
arthroplasty as often extends into the articular surface
what does Myositis ossificans look liek?
circumferential calcifications with lucent center
Corticol desmoid appearance
can be hot on bone scan
posterior medial epicondyle of the distal femur
What is the mnemonic for cystic bone lesions
FOGMACHINES
Cystic bone lesions by age
under 30
EG
ABC
NOF
Chondroblastoma and SOlitary bone cysts
cystic bone lession by age
over 40
Mets and myeloma
they say
malignant epiphyseal you sa
Clear cell chondrosarcoma
Epiphyseal bone cyst lesions
AIG C
ABC
Infection
GCT
Chondroblastoma
cystic bone lesions in the metaphysis
most of them
due to good blood supply especially bone mets and infeciton
what is fibrous dysplaia?
skeletal developmental anomaly of osteoblasts
failure of normal maturation and differentiation
What can fibrous dysplasia look like?
anything
McCune albright facts to know
precocious puberty
cafe au laits spots
girls
polyostotic fibrous dusplasia
Mazabraud facts to know
Polyostotic fibrous dysplasia
women
soft tissue myxomas
increased osseous malignant transformation
what is an adamantinoma
tibial lesion that resembles fibrous dysplasia. Potentially malignant.
Enchondroma is found where
medullary cavity - composed of hyaline cartilage
apperance of an enchondroma
lytic lesion with irregularly speckled clacification of chondroid matrix.
ARCS AND RINGS
though not found in fingers and toes
how to differentiate enchondroma vs low grade chondrosarcoma
history of pain
All the Ms of Maffucci relates to what
MORE .haemangiomas than enchondromas.
Malignant potential
Eosinophilic Granuloma (EG) classic apperance
vertebra plan in a kid
skull with beveled edge lesion
floating tooth with lytic lesion in alveolar ridg
Ddx for vertebra plana
MELT
Mets
EG
Lymphoma
Trauma/ TB
DDx for osseous sequestrum
OM
Lymphoma
fibrosarcoma
EG
Osteoid osteoma can mimic
What must the physis be in GCT
closed
Features of GCT
non sclerotic border
abut an articular surface
GCT most common in age
20 - 30
relationship of GCT and ABC
ABC can turn into GCT
Non ossifying fibroma seen in
children
Non ossifying fibroma classically found in
the knee
border feature of Non ossifying fibroma
sclerotic thin border
(GCT are thin walled)
what is a non ossifying fibroma called when less than 2cm?
fibrous cortical defect
NOF and fibrous corticl defects can also be called together
fibroxanthoma
what is Jaffe Campanacci syndrome
multiple NOF, cafe au laits mental retardation, hypogonadism and cardiac malforamations
night pain relieved by aspirin
osteoid osteoma
osteoid osteoma is found where
meta/diaphyiss of long bones.
spine
lots of oedema around a lesion
think osteoid osteoma
associations of osteoid osteoma
painful scoliosis
growth deformity
synovitis
arthritis
what is an osteblastoma
osteoid osteoma greater than 2cm
classically bone lytic metastases
RCC and thyroid
classic blastic lesions for bone mets
prostate
carcinoid
medulloblastoma
What is Multiple myeloma ?
Plasma cell proliferation increases surrounding osteolytic activity
appearance of MM in spine
Vertebral body destruction with sparing of the posterior elements
what is a plasmacytoma ?
discrete solitaroy neoplastic monclonal plasma cells in bone or soft tussues
counterpart to MM
Mini brain appearance
plasmacytoma in vertebral body
ABC are what?
aneurysma lesions, thin walled and blood filled.
(fluid fluid level on MRI)
can develop following trauma
think tibia
normally young patients
fallen fragment sign think
solitary bone cyst
Brown tumour is ax with what condition
hyperparathyroidism
what is a brown tumour
accumulation of giant cells and fibrous tissue
features of chondroblastoma
kids
thin sclerotic rim
extends across physeal plate
periostitis
NOT T2 BRIGHT
chondromyxoid fibroma
least common benign lesion of cartilage
patients young than 30
osteolytic typically,
elongated in shape
eccentrically located
metaphyseal lesion with corticol expansion
hip intertrochanteric region
ddx
lipoma
solitary bone cyst
monostotic fibrous dysplasia
benign lesion differentials for no pain / periostitis
fibrous dysplasia
enchondroma
NF
Solitary bone cyst
Multiple benign lesions differentials
Fibrous dysplasia
EG
Enchondroma
Mets/ Myeloma
hyperparathyroidism
liposclerosing myxofibroma location at the
intertrochanteric region of the femur
geographic lytic lesion with a sclerotic margin.
10% undergo malignant transofrmaiton
Osteochondroma associated with what treatment
radiation
Multiple osteochondroma - condition
multiple hereditoary exostosis
Trevor disease is also called
Dysplasia epiphysealis hemimelica
what is trevor disease?
oseochondromas in an epihpysis, serious joint deformity . O
Osteochondroma vs Supracondylar spurr?V
Osteochondroma points away from the joint
Periosteal chondroma
found where and what age group
lesion in the finger of a kid
What is osteofibrous dysplasia
what is appearnace
who does it affect
benign lesion found in tibia or fibula of children
anterior tibial bowing
Tibial bowing ax with NF1
NF1 antierior with fibular pseduoarthrosis
three categories of arthritis
Degenerative (OA, Neuropathic)
inflammatory (RA, Variants)
Metabolic (Gout, CPPD)
most common degenerative arthritis is
osteoarthritis
surgical like marings with arthritis think
neuropathic joint
gullwing in post menopaual women at the DIP joints
erosive osteoarthritis
Features of rheumatoid arthritis?
osteoporosis
soft tissue swelling
marginal erosision
unifrom joint space narrowing
bilateral and symmetric
spares the DUP joints
features of felty syndrome
RA for >10 years
splenomegaly
neutropenia
caplan syndrome
RA and pneumoconiosis
RA vs OA of th hip
OA is up and medial
RA is at an angle (10pM)
List some rheumatoid variants
Psoriatic arthritis
reisters syndrome (reactive arthritis)
Ank Spond
Inflammatory bowel disease
Psoriatic arthritis affects which joints
IP joint more than MCP joints
starts in the margins
ank spond in the hand, Pencil in cup, mouse ears all describe
Psoriatic arthritis of the phalanges
features of psoritatic arthritis
Asymmetric
distal IP joints
no osteoporosis
bone proliferation
causes mutilans if severe
features of RA
symmetric
proximal MCP
osteoporosis
no bone proliferation
causes mutilans if severe
reactive arthritis is similar to psotiatic arthritis except
found in feet
SI joints and ank spond
widens initially and then narrows
hits SI joints first!
in ank spond worry about any trauma always do
the CT spine
unilateral abnormal SI joints think
infeciton
asymmetric but both abnormal SI joints think
Psoriasis or reactive arthritis
symmetric both wrong SI joints think
INflammatory bowel or Ank Spond
Gout earliest sign
joint effusion
Gout has erosions located where?
juxta articular.
spares joint space until late in disease
phrases for gout
punched out lytic lesions
overhanging edges
soft tissue tophi
Gout on MR
juxta articular soft tissue mass low on T2
tophys will normally enhance
Gout mimickers what are they
RAASH
Amyloid
RA
reticular histocytosis
sarcoid
hyperlipidaemia
what does CPPD (pseudo gout) stand for
Clacium pyrophsophate disease
what is pseudogout in relation to CPPD
CPPD + synovitis is pseudo gout
CPPD favourited joints
TFC of wrist
peri odontoid tissue
intervertebral disks
what is a Milawaukee shoulder
destroyed shoulder due to hydroxyapatite crystals in the shoulder
how does haemochromatosis link to calcium pyrophsophate deposition
iron overload causes the deposition of CPPD
get chondrocalcinosis .
superiosteal bone resoroption on radial side of fingers think….
hyperparathyroidism
rugger jersey spine think
hyperparathyroidism
brown tumours assocaited with
hyperparathyroidism
terminal tuft erosions think
hyperparathyroidism
scleroderma
psoritatic arthritis
JPA
RA
Initial consideration of hand XR as to whether inflamatory or degenerative?
Inflamatory will be symmetric joint space norrowing with erosions
degenerative will be asymetric and osteophytes
if hand pathology is though to be inflammatory what does one joint vs multiple mean?
one joint means likely infeciton
multiple then think is there bony proliferation and what is the distribution
Erosion, multiple joints, proximal distribution
no bony proliferation
RA
Erosion, multiple joints
distal distribution and bony proliferation ddx are
AS
psoriasis
reactive arthritis
inflammatory bowel related
if asymmetric joint space narrowing
osteophytes
how to seperate types of degenerative
Typical joints - OA
Atypical joints / age - Post truama, gout/CPPD, hemophilia
Severe destruction - neuropathic
flowing syndesmophytes think
Ank SPond
Diffuse paravertebral ossifications think
DISH
focal lateral paravertebral ossification
psortiatic arthritis
Which conditions erode the dens
CPPD and RA
which condition gives bad Kyphosis
NF1
appearance of reducible deformity without erosions
SLE
what is Jaccoud arthropathy
Similar to SLE, non erosive arthropathy with ulnar devition of 2-5 mcp.
post rheumatic fever
what does DISH stand for
Diffuse idiopathic skeletal hyperostosis
What is DISH image features
anterior longitudinal ligament ossificaiotn more than 4 levels.
What is OPPL stand for
Ossficiation of the psoterior longidutindal ligament
who does destructive spondylarthropathy affect and where does it impact
those on dialysis
C spine
considered due to amyloid deposition
appearance of Juvenile idiopathic arthritis
wash out hand with proximal distribution (carpals buggered)
under 16
6 weeks duration
systemic onset - Stills - salmon pink rasdh and fever
Amyloid arthropathy appears as what
severe pattern of destruction
bilateral involvement of shoulder, hips, carpals, knees.
get carpal tunnel syndrome
post total hip athroplasty what is particle disease?
macrophages eat any particles (metal) spew enzymes everyhwere
What is stress shielding?
stress stransferred through the metallic stem, so bone is not loaded.
Wolffs Law.
Unloaded bone gets resorbed.
In who does stress shielding occur moer in ?
uncemented arthroplasty
stress shielding can cause
increase risk of fracture
is polyethylene wear normal
no
superior lateral to athroplasty, not normal
Heterotopic ossifications
what does it cause
stiff hip
Three components that exist in marrow
Trabecular
Red - making RBC
yellow - fat
what happens to red marrow as we grow up
replaced by yellow marrow.
can get some perisiting in femoral and humeral heads
What replaces marrow in osteoporosis
yellow marrow
How to differentiate red marrow from yellow
MRI
T1 fat bright for yellow. Red is darker
order of marrow conversion
epihpyses convert after ossification
then diaphysis then metaphysis
What happens in leukaemia?
proliferation of leukemic cells results in replacement of red marrow
marrow looks darker than muscle on T1.
which marrow diseases are not diffuse?
Waldenstroms macrolglobulinemia (infarcts)
Multiple myeloma ( focal deposits)
name a calcium hydroxyapatite deposition disease
calcific tendonitis
common location for calcium hydroxyapatite deposition disease
shoulder
supraspinatus tendon at insertion by the greater tuberosity
what is Osteopoikilosis?
bone islands
usually in epiphyses
inherited or sporadic
benign
How to differentiate between metastases and osteopoikilosis?
Osteopoikilosis will be joint centred. Sclerotic mets will be all over the place
Osteopathia striata is what>
In metaphysis of long bones.
linear, parallel and longitudinal lines
What is engelmanns disease?
progressive diaphyseal dysplasia or PDD.
Fusiform bony enlargement with sclerosis of the long bones.
bilateral or symmetric
long bones
hot on bone scan
can cause optic compression
Why does hip in acromegaly develop osteoarthritis
grows and out strips it blood supply .
What is pigmented villonodular synovities (PVNS)
uncommon benign neoplastic process
may involve synovium of the joint diffusely or focally.
can also affect the tendon sheath
PVNS of the tendon is called what
Giant cell tumour of the tendon sheath
Giatn cell tumour of the tendon sheath can cause what to underlying bone
erosion
Giant cell tumour of tendon sheath on MRI
T1 and T2 dark
Glomus tumour on MRI
T1 dark
T2 bright
Primary synovial chondromatosis what type are there
primary and secondary types
Primary synovial chondromatosis
secondary causes
degenerative causes
Primary synovial chondromatosis
primary causes
metaplastic / true neoplastic process forming
- multiple cartilagenous nodules in the synovium of joints, tendon sheaths and bursa
Benign neoplasia
Associated haemarthrosis
never calcifies
is it
Synovial chondromatosis or is it PVNS
PVNS
Bengin neoplasia
NOTE ax with haemarthrosis
may calcify
synovial chondromatosis
Diabetic myonecrosis
what is it, who does it affect
infected muscle
poor T1DM control
soft tissue hemangioma can enalrge during
pregnancy
soft tissue haemnagioma on CT
intralesion fat
Lipoma arborescens
what is it and buzzword
synovial lining of joints and bursa affected.
frond like depositions of fatty tissue
Lipoma arborescens affects who
50s and 70a
Lipoma arborescens seen in normal knee but also in
OA
chronic RA
prior trauma
Lipoma arborescens MRI features
T1 and T2 bright
What are the names of the signs for AVN of the hip
Double line sign
Rim sign
Crescent sign
AVN hip - what is the double line sign
T2, inner bright line of granulation tissue.
outer dark line of sclerotic bone.
AVN hip RIM sign
T2, signal line sandwiched between two low signal lines.
represents fluid between sclerotic borders of osteochondral fragment
(implies instability)
AVN hip crescent sign
seen on XR.
suchondral lucency, indicated imminent collapse
What are the stages of osteonecrosis
0 - normal
1 - normal xr, oedema on MR
2 - mixed lytic / sclerotic
3 - crescent sign
4 - secondary osteoarthritis.
Thalassemia is a defect in what
haemoglobin chain
What happens to sinuses in Thalassemia
obliterates
wide bones with thick trabecula think
Pagets
Three stages of pagets are
lytic to mixed to sclerotic
Pagets sign
Blade of grass sign
lucent leading edge in long bone
Pagets sign
Osteoprosis circumscripta
blade of grass in skull
Picture frame vertebra.
Pagets sign
all sides thickened
Pagets sign
cooton wool bone
thick disorganized trabeculae
Banana fracture
Pagets sign
insufficency fracture of a bowed bone
Pagets sign
Tam O’shanter sign
thick skull
xPagets sign
Saber shin
bowing of the tibia
Ivory vertebra.
Pagets sign
ddx include mets.
Pagets will be expansile
Complication of pagets
most common
deafness
pagets complications
general
spinal stenosis
cortical stress fracture
cranial nerve paresis
CHF
second hyperparathyroidism
Which tumour can pagets turn into
common
Osteosarcoma
what does pagets involve in the pelvis?
always incolves the iliopectineal line
thickness of plantar fascia is greater than 4mm
with loss of usual fibrillar pattern
fascitiis
split brevis happens in
inversion injury
outward convexity of the retroalleolar groove pushes into the PB. split it
who gets tear of posterior tibial tendon
old fat diabetic woman on chronic steroids
if lose posterior tibial what is the next
spring ligament
if that goes then los arch of the foot
Is there meatn to be fat in the sinus tarsi
yes
what causes sinus tarsi syndrome
dysfunction of the stability in the joint
common cause of acl reconstruction failure
missed posterolateral corner injury
oedeam in the fibular head think
is there a posterolateral corner injury
double PCL sign
bucket handle meniscus tear
shows the acl must be intact. . in order for it to flip like that
discoid minuscus
always lateral
high risk of tears
Wrisburg is most high risk
lipoma arborsecns
frond like shrub
sinovium gfull of fat from chronic inflammation
celery stick acl
mucoid degeneration
mimic an acl tear.
sublime tubercle of elbow
where UCL attaches and can tear from in valgus overload
who gets AVN
steroids
truama
sickle cell
alcoholic
double line sign
AVN
tip of the iceberg fracture on greter trochanter femur - next step
MRI to see the extent of the fracture
buford complex
Quadrant
anterior superior
middle GH ligament attaches too superiorly.
absent labrum
sublabral recess location where
superior
SLAP tear located where
superior
Sublabral foramen located
anterior superior
bankart exist where
anterior inerior
shoulder degenerative chnage happens to which structure
labrum
SLAP tears happen to who
overhead movements
Types of SLAP tears
1 - 4
4 - extension in to biceps anchor
most common SLAP
t2
anterior and /or psoterior extension
SLAP tear t3
bucket handle
spares the biceps tendon anchor
T4 SLAP tear
bieps short head attaches corocoid, long head 12 o clock positoin.
tearing extends in to the bicep.
Bankarts
glenoid
Hillsachs on
humerus
True bankart is damage to
BONE as well as periosteum
Aren’t you glad its a
GLAD
most mild
scraped cartilage off only
HAGL
avulsion of the glenohumerla ligament at the humerus
