RD MSK formatted Flashcards
- A patient with a known Charcot foot has an ulcer with a red swollen foot, the clinicians ask your advice to identify osteomyelitis at 7-10 days after the onset of swelling?
a. MRI
b. bone scan
c. PET
d. Xray
e. CT
ANSWER a. MRI= T, but often difficulta. MRI= T, but often difficult
- A patient with a known Charcot foot has an ulcer with a red swollen foot, the clinicians ask your advice to identify osteomyelitis at 7-10 days after the onset of swelling (SK)?
a. MRI= T, but often difficulta. MRI= T, but often difficult
b. Bone scan= F = Charcot joint will likely be positive whether infected or not (best NM test is combined leucocyte and sulfur colloid marrow subtraction study)
c. PET= F = see below
d. Xray= F = would do, but low diagnostic yield
e. CT= FACR guidelines state do MRI + x-rays (both rate 9, N/M rates
4)StatDx
• Radiograph is appropriately the first-line test; relatively insensitive; MR is gold standard
• Even MR may be nonspecific for osteomyelitis in the presence of Charcot joint changes
• Recent meta-analysis suggests high accuracy of FDG PET to diagnose chronic osteomyelitis (but see below)J Nucl Med July 1, 2011 vol. 52 no. 7 1012-1019
• 18F-FDG PET/CT, even with sequential imaging, has a low diagnostic accuracy for osteomyelitis and cannot replace WBC scintigraphy in patients with diabetic foot.
- Runner with fusiform increased uptake on bone scan. Most likely:
a. Shin splints
b. Stress fracture
c. Tumour
d. Normal variant
ANSWER b. Stress fracture
- Runner with fusiform increased uptake on bone scan. Most likely:
a. Shin splints
b. Stress fracture
c. Tumour
d. Normal variant
Stress fracture (StatDx, Mettler)
• Tibia: typically proximal posterior cortex
• NM:
o Usually focal, fusiform or oval configuration of increased activity (more focal than shin splints)
o Typically positive on all 3 phases of bone scan
• MRI: highly specific
o T1 shows linear fracture line
o Fluid sensitive sequences: fracture line, surrounding marrow edema, & circumferential soft tissue signal
Shin splints (medial tibial stress syndrome) – spectrum of stress response to tibia (i.e periostitis – with no # formation yet)
• NM: Metter p273
o Normal blood flow & blood pool images
o On delayed images get linear increased activity along > one-third length of posteromedial tibial cortex at insertion of soleus muscle
• MRI: StatDx
o Linear hyperintense periosteal oedema/fluid in direct contact with medial tibial cortex (T2WI). Hyperintense edema/fluid extends anteromedial to posteromedial, and extends to orgin of soleus posteromedially (soleus bridge),
o Marrow hyperintensityMRI is the most sensitive test for stress injury, followed by NM.
- Runner with shin pain and transverse, linear uptake posteromedially on bone scan. Most likely:
a. Shin splints
b. Stress fracture
c. Tumour
d. Normal variant
*LW: possibly poor recall (transverse linear uptake, if stated vertical linear uptake, would favour shin splints, however based on stem I think stress fracture would be best option)
Shin splints show: Linear, superficial posterior medial tibial cortex, ≥ 1/3 of tibial length
Angiographic phase hyperemia absent/minimal.
Bone scan:
Normal blood flow & blood pool images
On delayed images get linear increased activity along > one-third length of posteromedial tibial cortex at insertion of soleus muscle
MRI:
Linear hyperintense periosteal oedema/fluid in direct contact with medial tibial cortex (T2WI). Hyperintense edema/fluid extends anteromedial to posteromedial, and extends to orgin of soleus posteromedially (soleus bridge),
Stress fracture / Fatigue Fracture:
Tibia: typically proximal posterior cortex
NM:
o Usually focal, fusiform or oval configuration of increased activity (more focal than shin splints)
o Typically positive on all 3 phases of bone scan
MRI:
o T1 shows linear fracture line
o Fluid sensitive sequences: fracture line, surrounding marrow edema, & circumferential soft tissue signal
ANSER:a. Shin splints T see above
- Runner with shin pain and transverse, linear uptake posteromedially on bone scan. (?? Transverse – maybe bad recall, meant longitudinal possibly)
a. Shin splints T see above
b. Stress fracture
c. Tumour
d. Normal variant
- A 60 year old man. Hot warm knee, swelling. Acute. Symmetrical loss of joint space with erosions on plain film. No other joints involved.
a. Trauma
b. Infection
c. Rheumatoid arthritis
d. Seronegative arthropathy
e. Gout
f. OA
ANSER:b. Infection= T (must be excluded)
- A 60 year old man. Hot warm knee, swelling. Acute. Symmetrical loss of joint space with erosions on plain film. No other joints involved.
a. Trauma= F
b. Infection= T (must be excluded)
c. Rheumatoid arthritis = F
d. Seronegative arthropathy = possible, but unlikely – the most common (AS) starts with sacroiliitis, and then tends to be a asymmetric polyarthropathy
e. Gout = F clinically possible, but a key feature is preservation of the joint space until relatively late
f. OA= F
Single joint = suspect infection;
DDx is crystal-deposition, PVNS, seronegative
Symmetric JS loss = inflammatory or crystal-deposition (although with gout often have partial preservation of JS); JS destruction in septic arthritis
Erosions = septic, inflammatory incl. seronegative, goutMust rule out infection
- Young man, acute pain in knee, afebrile, no other joints affected, no recent history. Imaging showed symmetrical jt narrowing and osteophytes. Most likely?
a. Trauma
b. Seronegative arthropathy
c. CPPD
d. Rheumatoid arthritis
ANSER:b. Seronegative arthropathy T most likely is reactive (Reiter) arthritis – men 20-40 years, uniform JS narrowing, erosive changes, osteophytes
*LW: agree this is most likely, however “no recent Hx” would semi argue against it, as would expect some form of Hx of a GI GU infection.
- Young man, acute pain in knee, afebrile, no other joints affected, no recent history. Imaging showed symmetrical jt narrowing and osteophytes. Most likely?
a. Trauma F if secondary to trauma would be asymmetric JS narrowing
b. Seronegative arthropathy T most likely is reactive (Reiter) arthritis – men 20-40 years, uniform JS narrowing, erosive changes, osteophytes
c. CPPD F occurs > 50 years
d. Rheumatoid arthritis F
- Melorrheostosis - NOT complicated by:
a. Malignant transformation
b. Muscle atrophy
c. Contractures (skin)
d. Sclerotomal distribution
ANSER:Probably Aa. Malignant transformation = ?F – isolated cases reported (bonetumor.org), not in Dahnert though
- Melorrheostosis - NOT complicated by:
a. Malignant transformation = ?F – isolated cases reported (bonetumor.org), not in Dahnert though
b. Muscle atrophy = T (present in some cases – F. Chew)
c. Contractures (skin) = T (flexion contractures)
d. Sclerotomal distribution = TDahnert, MSK Req p628, MSK Companion (F. Chew), StatDx & http://www.bonetumor.org/tumors-foot-and-ankle/melorheostosis
• Non-hereditary, idiopathic
• Assoc/ w/ osteopoikilosis, osteopathia striata, vascular malformations/tumours
• Monomelic in sclerotomal distribution
• Dense bone deposited along cortex (usually periosteal, but can be endosteal), usually involving only one side of the involved bone/s
• Candle-wax dripping
• May cross joint
• Flexion contractures
• Isolated cases of malignancy have been reported in association with melorheostosis, one osteosarcoma and one malignant fibrous histiocytoma.
StatDx says “Rarely associated with other bone malignancy such as giant cell tumor or osteosarcoma”.
• Bone scan: Increased blood flow on angiographic, blood pool, and delayed images
- 40 year old woman. Chronic pain, acutely worse. US shoulder shows anechoic region in thickened supraspinatus extending from humeral head surface to bursa
a. Partial tear at joint side
b. Full thickness tear
c. Partial tear bursal side
d. Calcific tendinitis
e. CPPD
anser: b. Full thickness tear
7. 40 year old woman. Chronic pain, acutely worse. US shoulder shows anechoic region in thickened supraspinatus extending from humeral head surface to bursa
a. Partial tear at joint side
b. Full thickness tear
c. Partial tear bursal side
d. Calcific tendinitis
e. CPPD
Terminology (MSK Req p92)
• Full thickness tear = perforation that extends from bursal to articular surfaces
• Complete tear = disruption of entire tendon
MSK cases – US criteria for full-thickness supraspinatus tear
• Nonvisualization of the tendon or focal tendon defect filled with fluid and debris, with loss of the normal outward convexity of the tendon and dipping of the deltoid muscle into the tendon gap.
• The uncovered cartilage sign or naked cartilage sign is the hyperechoic interface between the joint fluid and the cartilage covering the humeral head.
• Other US signs are bone irregularity of the greater tuberosity, joint effusion, and fluid in the subdeltoid bursa
- SCFE . Slippage of femoral head is:
a. Posterior and medial
b. Posterior and lateral
c. Anterior and medial
d. Anterior and lateral
a. Posterior and inferomedial
O For which condition is US NOT the best first best
a. rotator cuff tear
b. instability
c. adhesive capsulitis
d. impingement
e. bursitis
B
According to Imaging pathways (WA)
a. rotator cuff tear = T = US + XRs
b. instability = F = XR then MR arthrography or CT arthrography
c. adhesive capsulitis F = MR arthrography modality of choice
d. impingement = T = US + XRsE = T = US
e. bursitis likely true
Oblique spiral fibula fracture from joint level
Webber B???
SUFE a. rare diagnosed on AP B. usually 5-10 years of ages C. usually bilateral d. usually posteromedial slippage E. early slippage frog leg view is best
So D or E??
A = F, can be seen often B = F, typically 10-16 years (growth spurt), esp. obese, males & blacks C = F, bilateral in 25-33% D = T, epiphysis is rotated posteriorly & inferomedially E = T
Emedicine: The lateral radiograph demonstrates slippage earliest because the slippage begins with posterior displacement and progresses with medial rotation.
Which is a recognised feature of OA
a. subchondral sclerosis
b. osteopneia
c. subluxation
d. erosions
Probably A
A = T (subchondral sclerosis, asymmetric JS narrowing, osteophytes, subchondral cysts = OA)
B = F (inflammatory arthropathy)
C = T (can occur at 1st CMCJ, hip joint, patellofemoral joint, glenohumeral joint – StatDx)
D = ?F (erosions do not occur in the hand in pure OA, do occur in erosive OA – StatDx)
- Male, 50 year old patient, distal arthropathy including the (middle & index) PIPJ and DIPJ, soft tissue swelling, some erosions, most likely
a. Rheumatoid arthritis
b. Erosive arthritis
c. Seronegative arthritis
d. OA
ANSWER:c. Seronegative arthritis T – psoriasis most likely, but usually DIPJ predominance and asymmetric; against it is age & lack of ST swelling
- Male, 50 year old patient, distal arthropathy including the (middle & index) PIPJ and DIPJ, soft tissue swelling, some erosions, most likely
a. Rheumatoid arthritis Possibly T, but typically more proximal joints; 3x’s more common in females
b. Erosive arthritis ? T – gull-wing deformity (central erosions + peripheral osteophytes), soft tissue swelling, distal distribution; main negative is most commonly occurs in post-menopausal females (F»M 12:1, Statdx)
c. Seronegative arthritis T – psoriasis most likely, but usually DIPJ predominance and asymmetric; against it is age & lack of ST swelling
d. OA – F – productive only, no erosionse. ?
- 20 year old patient, knee pain, joint space narrowing (symmetric), some osteophyte formation, most correct
a. Previous trauma
b. Infection
c. Rheumatoid
d. OA
e. Seronegative
f. PVNS
- 20 year old patient, knee pain, joint space narrowing (? Symmetric), some osteophyte formation, most correct ANSWER: ? seronegative (*LW agrees)
Previous trauma ?T = possible, with secondary OA, common site; usually not symmetricg.
Infection = ?T = symmetric JS narrowing; usually no osteophytes until secondary OA occurs – may have been due to previous infection as a child?
h. Rheumatoid = JS narrowing that is uniform, erosions, effusion, osteopenia; but wrong demographic (usually women 40-70 years)
i. OA= asymmetric JS narrowing; older age
j. ? Seronegative = most likely is reactive (Reiter) arthritis – men 20-40 years, uniform JS narrowing, erosive changes, osteophytes
k. ? PVNS = no JS narrowing
- Soft tissue mass near the ankle, 30 year old female, High T2, peripheral enhancement, most correct
a. Synovial sarcoma
b. Myxoid sarcoma
c. Ganglion
d. Giant cell tumour
ANSWER: c. Ganglion – T2 very bright; can have thin enhancement of wall; usually about the wrist, also occur about knee & ankle
- Soft tissue mass near the ankle, 30 year old female, High T2, peripheral enhancement, most correct (StatDx)A
a. Synovial sarcoma – T2 heterogeneous hyperintensity; most common around knee & foot; age 16-36; marked heterogeneous enhancement
b. Myxoid sarcoma – most common in lower extremity, esp. in thigh; T2 intermediate-high signal (myxoid = high T2 signal in general); variable enhancement (myxoid tissue typically hypoenhancing)
c. Ganglion – T2 very bright; can have thin enhancement of wall; usually about the wrist, also occur about knee & ankle
d. Giant cell tumour- can involve tendon sheaths of ankle/foot (although favours hand & wrist); variable T2 hypo-hyperintensity (internal hypointensities due to haemorrhage); intense enhancement +/- heterogenous
- Child sustains a forearm injury, pain at the wrist with a deformity at the mid forearm, most likely?
a. Distal radius fracture with ulna bowing
b. Distal radius fracture with dislocation at the distal radial ulnar joint
c. Ulnar midshaft fracture with radial head dislocation
d. Fracture scaphoid
ANSWER:b. Distal radius fracture (?metaphysis) with dislocation at the distal radial ulnar joint
- Child sustains a forearm injury, pain at the wrist with a deformity at the mid forearm, most likely?
a. Distal radius fracture (?metaphysis) with ulnar bowing
b. Distal radius fracture (?metaphysis) with dislocation at the distal radial ulnar joint
c. Ulnar midshaft fracture with radial head dislocation
d. Fracture scaphoidReferring to Galeazzi fracture (see pic below) = fracture of radial shaft (mid-distal) with DRUJ subluxation
(FROG = fractured radius of galeazzi)c.f. Monteggia fracture = fracture of proximal ulnar shaft with radial head dislocation
- 41 year old runner presents with leg pain. Bone scan show linear uptake in the posteromedial tibia. Which is MOST likely?
a. Shin splint
b. Stress fracture
c. Normal variant
d. Primary bone tumour
e. Metastasis
B. shint splint
Stress fracture (StatDx, Mettler)
• Tibia: typically proximal posterior cortex
• NM:
o Usually focal, fusiform or oval configuration of increased activity (more focal than shin splints)
o Typically positive on all 3 phases of bone scan
• MRI: highly specific
o T1 shows linear fracture line
o Fluid sensitive sequences: fracture line, surrounding marrow edema, & circumferential soft tissue signal
Shin splints (medial tibial stress syndrome)
• NM: Metter p273
o Normal blood flow & blood pool images
o On delayed images get linear increased activity along > one-third length of posteromedial tibial cortex at insertion of soleus muscle
• MRI: StatDx
o Linear hyperintense periosteal oedema/fluid in direct contact with medial tibial cortex (T2WI). Hyperintense edema/fluid extends anteromedial to posteromedial, and extends to orgin of soleus posteromedially (soleus bridge),
o Marrow hyperintensityMRI is the most sensitive test for stress injury, followed by NM.
- Patient presents with shoulder pain. Plain x-ray is normal. Clinically subacromial bursitis is suspected. Which is the NEXT most appropriate investigation?
a. CT
b. MRI
c. USS
d. NM Bone Scan
e. Repeat x-ray in 7-10 days
Ultrasound. As per WA imaging guideline. Imaging, 2003 (UK)
The primary purpose of imaging in impingement is to demonstrate if there is a tear and to assess its size. The degree of atrophy of the rotator cuff muscle has been cited as an indicator of predicting the rate of rerupture but it is unclear whether this is an important consideration in the younger population with small or medium sized tears that make up the major of those patients who undergo surgery [7].
US and MRI are the two main tests used in impingement. US has the advantage of being a rapid and accurate method of diagnosing rotator cuff tears and is suitable for one-stop combined clinics with instant access to scanning.
MRI is also an accurate technique for tears and gives a broader overview of the shoulder. MRI is expensive, often disliked by patients and not amenable to providing an instant access service. If the question to be answered is “is there a rotator cuff tear” then US is the preferred technique. Bursal abnormalities, including dynamic signs of impingement, calcific deposits, and irregularity of the greater tuberosity are other common findings that are clearly identified on US.UTD, 2011 (USA)Magnetic resonance imaging — MRI is the preferred imaging study for patients with suspected impingement and rotator cuff injury. A normal MRI suggests that the likelihood of a rotator cuff tear is less than 10 percent [30-32]. On the other hand, MRI findings for rotator cuff tears are not highly specific, particularly in older patients [33]. The sensitivity and specificity of MRI for the diagnosis of impingement are approximately 93 and 87 percent, respectively [34]. MRI is also useful in the evaluation of avascular necrosis, biceps tendinopathy and rupture, inflammatory processes, and tumors [35].Ultrasonography — In the hands of skilled operators, the diagnostic accuracy of ultrasound has been found to be the equivalent of MRI in identifying rotator cuff tears, labral tears, and biceps tendon tears and dislocations [36-42]. Ultrasound is less expensive than MRI and preferred by patients [42,43].
- 20 yo. Round soft tissue mass around knee. CT shows lots of calc. Most likely
a. fibroma
b. desmoid
c. gouty tophus
d. synovial sarcoma
Probably Synovial sarcoma ( can calcify)
A – fibroma (?T) – possibly a fibroma of tendon sheath – low-intermediate T1, heterogenous low-high signal on T2, variable enhancement (StatDx); Dahnert says fibroma of soft tissue hypointense nodule on all MR sequences. Have seen one at PAH immediately above upper pole of patella which was T2 hypointense. However can’t find calcification in any reference.
B – desmoid = deep fibromatosis – T2 iso to muscle, T2 intermediate to hyperintense, no calcs
C – tophus = unlikely in 30 yo male; usually not calcified unless renal failure; gouty tophus low-intermediate T2 signal (Dahnert; StatDx says variable signal)
D = synovial sarcoma (?T) = best answer = 20’s to 40’s, most occur about knee or thigh; calcification in 30%; usually T2 heterogenously hyperintense though (hypointense components).Soft tissue lesion with calcification near a joint → think of SS.
- optimal position to image infrapsinatous on US.
b. internal rotation, arm behind back
c. internal rotation, touching opposite shoulder
*LW:
Radiopedia state hand on opposite shoulder
radiographics: start hand on lap supinated, and if required progress to hand on opposite shoulder.
Suprapinatus position: hand reaches to get wallet from back pocket position.
Biceps: Patient position: arm in neutral position, elbow flexed 90 degrees, forearm supinated (palm up).
Subscapularis: Patient position: arm in neutral position, elbow flexed 90 degrees, forearm supinated (palm up), and then externally rotated.
Probably C.
• Infraspinatus
o Back of hand placed behind the back (shoulder extended in IR) or forearm supinated & placed on thigh +/- slight IR (Radiology 2011) or place hand on opposite shoulder (ESR)
o From SST pan posteriorly to IST – tendons difficult to separate at US
o Can also image IST by moving transducer posteriorly, often aided by passive IR & ER
Production line worker. Shoulder pain. Suspect impingement. Xray normal. Next best test: A. US B. MRI C. CT D. Re-xray in 10 days
US- in train specialist these can be as effective as MRI
Fracture proximal fibula + talar shift =
maisonneuve.note. dupentures # - think of bimalleolar # with tibiofibular ligament rupture and talar shift
What is a toddler #
Toddler fracture: Clinically subtle lower extremity fracture in a toddler or young child that results in refusal to bear weight, gait disturbance, or inability to walk. Possible sites of toddler’s fractures are midshaft of tibia (spiral), proximal tibia, distal fibular metadiaphysis, cuboid, calcaneum, talus & metatarsals.
Woman with increasing pain in shoulder. US thickened supraspinatous. Echogenic stuff in bursa or tend? with some shadowing. Most likely A. CPPD. b. HADD. C. partial tear D. full tear
b. HADD (calcified tendinosis of supraspinatous tendon)
Woman with increasing pain in shoulder. US thickened supraspinatous. Echogenic stuff in bursa or tend? with some shadowing. Most likely A. CPPD. b. HADD. C. partial tear D. full tear
b. HADD (calcified tendinosis of supraspinatous tendon)
Definition of foot malformations
a. club foot is tailpipes equinovarus
b. def of pes.
c. valgus is foot turned medially
A = T B = ? (pes means foot) C = F (turned laterally)
• Pes: the foot
• Talipes: a congenital deformity in which the foot is twisted out of shape or position
• Hindfoot equinus: fixed plantarflexion of the calcaneus (distal end pointing down)
o Evaluated only on lateral WB film
o Decreased calcaneal pitch (< 200)
o Calcaneal-tibial angle > 90deg
• Hindfoot calcaneus: calcaneus excessively dorsiflexed (calcaneal-tibial angle < 60deg)
o Seen in cavus & spastic deformities
• Hindfoot varus: distal bone of hindfoot (calcaneum) is angled too far medially in relation to the more proximal bone of the hindfoot (talus)
o Assessed with DP & lateral WB films
o AP talocalcaneal angle < 150 (approaching parallelism of bones); talus will point lateral to MT1 (normally passes thru or just medial to MT1)
o Lateral talocalcaneal angle < 250 (bones approach parallelism)
• Hindfoot valgus: calcaneum angled too far laterally in relation to the taluso AP talocalcaneal angle > 40deg; talus will point medial to MT1 (normally bisects MT1)
o Lateral talocalcaneal angle > 45deg (talus has increased plantarflexion)
• Forefoot varus: forefoot angled medially relative to the hind/midfoot – forefoot is inverted & often slightly supinatedo Forefoot appears narrowed on DP radiograph, with increased convergence of the bases of the metatarsals
o On lateral view metatarsals have a ladder-like arrangement, with the 5th MT in the most plantar position
• Forefoot valgus: forefoot angled laterally relative to the hind/midfoot – forefoot is everted & often pronatedo Forefoot appears broadened on DP radiograph, with a decrease in overlap of bases of metatarsals
o On lateral view the metatarsals are more superimposed & the 1st MT becomes the most plantar (normally 5th MT is most plantar)
• CTEV consists of
o Hindfoot equinus
o Hindfoot varus
o Forefoot varus
o AKA “clubfoot”
RA
a. age of presentation is 20-40
b. effusion happens late
c. peri-articular osteopenia is a sign of early disease
ANSWER: c. hallmark (periarticular erosion = early disease)- age of presentation is 40-70- effusion is an early sign
**LJS - recent Robbins, age 20-50yr
*LW: RP states Onset is generally in adulthood, peaking in the 4th and 5th decades = 30s-40s, effusions happen EARLY, peri articular osteopenia is relatively early that progresses to more diffuse osteopenia…. so maybe question was which is false?
27) Dwarf. Low back pain radiating down both legs. Most likely cause:
i) Overexaggerated lordosis of sacrum
ii) Short pedicles
iii) Scalloping of vertebral bodies
iv) Scoliosis
v) Sacrosciatic action
ANSWER:ii) Short pedicles T – short pedicles with lumbar spinal canal stenosis and disc prolapse can result in severe neurologic deficits (Apley
)i) Overexaggerated lordosis of sacrum = F
ii) Short pedicles T – short pedicles with lumbar spinal canal stenosis and disc prolapse can result in severe neurologic deficits (Apley)
iii) Scalloping of vertebral bodies = F – this does occur, but doesn’t account for S&S
iv) Scoliosis = F
v) Sacrosciatic action= F, although small sacrosciatic notches are a feature
28) Chance fracture following MVA. Most relevant:
i) Almost universally has neurological deficit
ii) Vertebral disc distraction
iii) Spinal cord injury
iv) Flexion compression fracture of middle column
ANSWER:iii) Spinal cord injury T – cord injury can occur due to retropulsion of posterior vertebral body cortex (StatDx), but as above it is uncommon.
2) Chance fracture following MVA. Most relevant:
i) Almost universally has neurological deficit F neurologic damage is uncommon, although the injury is unstable (Apley). MSK CRS – acutely unstable – pure osseous fractures heal well with long-term stability likely, while pure ligamentous injuries have high risk of residual instability. Neurologic injury in 20% (Dahnert)
.ii) Vertebral disc distraction F anterior compression to disc/body (StatDx)
iii) Spinal cord injury T – cord injury can occur due to retropulsion of posterior vertebral body cortex (StatDx), but as above it is uncommon.
iv) Flexion compression fracture of middle column F - Compression injury of anterior column with distraction of middle & posterior columns (StatDx)15-80% (> 50%) have significant abdominal injuries (bowel & mesentery most common)
29) Spondyloepiphyseal dysplasia. NOT a feature:
i) Atlanto-occipital instability
ii) Kyphosis
iii) Normal sized hands and feet
iv) Coxa vara
v) Normal femoral head ossification
ANSWER:v) Normal femoral head ossification F epiphyseal dysplasia – ossification of epiphyses delayed, often being irregular & fragmented; early OA
3) Spondyloepiphyseal dysplasia. NOT a feature: MSK Req p636
i) Atlanto-occipital instability T C1-2 instability with dens hypoplasia
ii) Kyphosis T progressive kyphoscoliosis (Dahnert)
iii) Normal sized hands and feet T normal or slightly shortened limbs, with multiple accessory epiphyses in hands & feet
iv) Coxa vara T severe coxa vara + genu valgum
v) Normal femoral head ossification F epiphyseal dysplasia – ossification of epiphyses delayed, often being irregular & fragmented; early OA
30) 15yo male. Generalised bone pain. Cardiomegaly. Broad ribs. Flattened thoracic vertebrae. Most likely \:i) Glycogen storage disease ii) Sickle cell iii) Thalassemia iv) Fibrous dysplasia v) Mets
iii) Thallasaemia T get expansion of the marrow cavity, osteopaenia, crush fractures, H-shaped vertebra, anaemia leading to high output cardiac failure
31) Which is the most correct regarding a cortical desmoid?
i) Posteromedial condyle
ii) Lateromedial condyle
iii) Increased signal on STIR imaging
iv) Increased uptake on bone scan in 70%
v) Biopsy required for diagnosis
ANSWER:iii) Increased signal on STIR imaging T high T2/STIR signal at site
5) Which is the most correct regarding a cortical desmoid? (= distal femoral metaphyseal irregularity)
i) Posteromedial condyle F posteromedial femoral metaphysis just lateral to adductor tubercle
ii) Lateromedial condyle F
iii) Increased signal on STIR imaging T high T2/STIR signal at site
iv) Increased uptake on bone scan in 70% F normal or slightly increased uptake
v) Biopsy required for diagnosis F don’t touch lesion
Cortical desmoid is a benign shallow cortical irregularity seen in older children or adolescents. It is recognised at specific metaphyseal sites, the most common being the medial posterior aspect of the distal femoral metaphysis at the insertion of the adductor magnus aponeurosis. Other sites include the proximal tibia, medial aspect proximal humerus and distal radius. The sites generally coincide with muscle or tendon insertions and it has been suggested that the lesion may reflect a chronic avulsion injury. The lesions are 1 to 3 cm. in size, irregular, with areas of lucency and areas of sclerosis. There may be some mineralization within the lesion. The margin may be latent or active. Bone scan will show uptake due to the presence of reactive bone, then become “cold” as the lesion involutes. CT scan will differentiate this lesion from osteoid osteoma and show the complex nature of the lesion, with areas of cortical thinning and thickening, some possible small “cystic” araes, and the surrounding mild sclerotic bone reaction. MRI in general is helpful but can be confusing. Biopsy is not indicated or warranted. A lesion whose nature is in doubt should be referred by an orthopaedic oncologist.
32) 80yo man with rib pain. Bone scan shows fusiform increased posterolaterally in left 7th rib. Most likely:
i) Myeloma
ii) Met
iii) Fracture
iv) Osteoid osteoma
v) Infection
ANSWER:iii) Fracture T Usually focal (punctate foci of ↑ activity) rather than infiltrative or elongated. More likely if ≥ two consecutive ribs are involved.
6) 80yo man with rib pain. Bone scan shows fusiform increased posterolaterally in left 7th rib. Most likely:
i) Myeloma F Unlikely to be single; sensitivity for lesion detection 75-85%, but poor sensitivity for lytic/trabecular lesions
ii) Met ? T More linear-type increased uptake, usually multiple (single lesions less commonly neoplastic, however metastastic disease not excluded). Mettler – a single focus of increased activity in a rib is due to metastases in only 10% of cases. A key exception is single sternal focus in woman with breast cancer (80% chance of being a met).
iii) Fracture T Usually focal (punctate foci of ↑ activity) rather than infiltrative or elongated. More likely if ≥ two consecutive ribs are involved.
iv) Osteoid osteoma F
v) Infection F
33) 20yo jogger with left shin pain. Focused left lower limb bone scan shows increased uptake in the proximal fibula. Most likely:
i) Normal variant for age
ii) Osteoid Osteoma
iii) Shin Splints
iv) Stress fracture
v) Metastasis
vi) Primary bone tumour
ANSWER:iv) Stress fracture – StatDx NM: Usually focal, fusiform or oval configuration of increased activity; positive on all three phases. More focal/fusiform c.f. medial tibial stress syndrome. Fibular stress fracture usually distal third but can be in proximal third.
7) 20yo jogger with left shin pain. Focused left lower limb bone scan shows increased uptake in the proximal fibula. Most likely:A
i) Normal variant for age
ii) Osteoid Osteoma Typically have intense uptake on bone scan. Should have pain at the site, worse at night & relieved by aspirin/NSAIDs.
iii) Shin splint – F – Shin splint = medial tibial stress syndrome. StatDx: Radionuclide activity posteromedial border tibia on delayed images (involves ≥ 1/3 length of tibia), but normal blood flow & blood pool. MRI = Hyperintense edema/fluid signal (T2WI) medial tibial border. Often bilateral. See Mettler NM p270-. Occurs at insertion of soleus muscle
.iv) Stress fracture – StatDx NM: Usually focal, fusiform or oval configuration of increased activity; positive on all three phases. More focal/fusiform c.f. medial tibial stress syndrome. Fibular stress fracture usually distal third but can be in proximal third.
v) Metastasis - F
vi) Primary bone tumour - F
34) Least correct regarding osteoarthritis \:i) Reduced mineralization ii) Erosions iii) Unilateral / asymmetrical iv) Subluxation v) Osteophytes
ANSWER:i) Reduced mineralization F usually no osteopenia, usually have sclerosis
8) Least correct regarding osteoarthritis:
i) Reduced mineralization F usually no osteopenia, usually have sclerosis
ii) Erosions T/F can occur in erosive OA, subchondral cysts in conventional OA
iii) Unilateral / asymmetrical T
iv) Subluxation T – atypical, but can occur in SLAC wrist
v) Osteophytes T
35) A 7 y.o girl comes in with hip pain and fever. Normal x-ray. What would be the next most appropriate examination to perform?
i) Bone scan
ii) MR
Iiii) Repeat films in 7 - 10 days time
iv) Bilateral Hip US
ANSWER:iv) Bilateral Hip US
9) A 7 y.o girl comes in with hip pain and fever. Normal x-ray. What would be the next most appropriate examination to perform?
i) Bone scan Only if XR & US unhelpful & usually only if MRI not available
ii) MRI May be indicated, but not as next step
iii) Repeat films in 7 - 10 days time
iv) Bilateral Hip US
36) Elite rugby player with recurrent dislocations. GP rings wanting to know best assessment. You say \:i) US ii) Xray iii) CT iv) MRI v) Bone scan
ANSWER: MRI
10) Elite rugby player with recurrent dislocations. GP rings wanting to know best assessment. You say:
i) US
ii) Xray
iii) CT
iv) MRI
v) Bone scan
UTD 2011MR arthrography is the method of choice for imaging the labrocapsular structures. MR arthrography is the most accurate imaging modality for sports injuries of the shoulder and in evaluating instability.
37) MRI shoulder in young guy with shoulder pain. Area of high signal in supraspinatus tendon only visualised on T1 sequences.
i) Full thickness supraspinatus tear
ii) Magic angle
iii) Partial thickness supraspinatus tear
iv) Anisotropy of tendon
ANSWER: MAGIC ANGLE
Magic angle refers to spuriously increased signal intensity that may occur within any tissue containing highly structured collagen fibers (tendon, ligament, meniscus, labrum), depending on its position within the magnetic field. This magic angle effect is due to the orientation of the collagen bundles and occurs when the structure lies at an angle near 55 degrees to the main magnetic field. The resulting increased signal is seen on images obtained with a short TE (T1, proton density, and most gradient echo sequences), but disappears on long TE (T2W) images. This latter feature allows for differentiation from true tendon pathology. Other supportive signs include a lack of tendon enlargement or peritendinous edema.In the shoulder, this phenomenon occurs commonly about 1 cm proximal to the insertion of the supraspinatus tendon on the greater tuberosity, which is the hypovascular region of the tendon, also known as the critical zone.The intermediate signal intensity from the magic angle phenomenon disappears with long TE sequences, such as T2W images, making it possible to differentiate magic angle from an abnormal tendon. A good rule to distinguish the magic angle phenomenon from a tear on T2* images is that the signal intensity within the tendon is never higher than the signal intensity within the adjacent muscle if it is from the magic angle phenomenon (see Fig. 10-2), whereas with a tendon tear, the signal intensity is higher than that of muscle.
38) US shoulder in young guy with shoulder pain. Supraspinatus tendon normal morphology/thickness and no fluid in subdeltoid/subacromial bursa. Decreased echogenicity and no visualisation of internal fibres at insertion. Likely due to:
i) Full thickness supraspinatus tear
ii) Magic angle
iii) Partial thickness supraspinatus tear
iv) Anisotropy of tendon
ANSWER: ANISOTROPY OF TENDONAnisotropy is the property of tendons, nerves and muscles to vary in their ultrasound appearance depending on the angle of insonation of the incident ultrasound beam. Loss of reflectivity in tendons may also denote underlying disease. A lesion can only be confirmed if a poorly reflective area remains when the angle of insonation is perpendicular to the long axis of the tendon.
39) Morton’s neuroma
Morton neuroma (StatDx): • Best diagnostic clue: Soft tissue mass between ± distal to 3rd + 4th metatarsal heads (3rd intermetatarsal space) • Location: 3rd common digital branch of medial plantar nerve, plantar to deep transverse intermetatarsal ligament • Intermediate to hyperintense on FS PD FSE + STIR images • Effacement of plantar subcutaneous fat by convex border of teardrop-shaped mass
40) SLE arthopathy is NOT associated with:
a. Subluxations and soft tissue calcification
b. Bilateral and symmetrical distribution
c. Periarticular osteopaenia
d. Erosions
e. Osteonecrosis
f. Soft tissue swelling
ANSWER:d. Erosions
14) SLE arthopathy is NOT associated with:
a. Subluxations and soft tissue calcification – T Prominent MCPJ subluxations; 10% have SC calcifications
b. Bilateral and symmetrical distribution T
c. Periarticular osteopaenia T may be seen
d. Erosions F – no erosions, JS narrowing uncommon
e. Osteonecrosis T high incidence of AVN due to steroids & the vasculitis (acute necrotising vasculitis of small arteries)
f. ? Soft tissue swelling T
41) YOUNG MAN WITH RIB LESION. destruction and pleural effusion.
a) askin tumour
b) fibrous dysplasia
c) neuroblastoma metastasis
ANS = A = Askin tumour (StatDx):
• Primitive neuroectodermal tumor (PNET) arises in pleura or chest wall (i.e. related to Ewing & other PNET type tumours)
• Although rare, most common pleural tumor in teenagers & young adults (especially females)• Often large
• Involves rib 23-60% of time
42) Which of the following is not associated with melorheostosis…
a. Muscle atrophy
b. Contractures
c. Sclerotomal distribution
d. Juxta-articular
e. malignant transformation
f. Soft tissue calcification
e. Malignant transformation T/F – some case reports of this… (but not mentioned in Dahnert)
Which of the following is not associated with melorheostosis…
a. Muscle atrophy T common
b. Joint contractures T flexion contractures of hip & knee
c. Sclerotomal distribution T monomelic
d. Juxta-articular T predominantly affects the diaphysis, but may extend into epiphysis & even cross the joint
e. Malignant transformation T/F – some case reports of this… (but not mentioned in Dahnert)
f. Soft tissue calcification T para-articular soft tissue ossification is uncommon, but can occur in severe cases (Dahnert says ossified soft-tissue masses in 27%)
43) 40 yo man with painful arc. 30-60 yo. Most likely U/S finding
a. complete supraspinatous tendon tear
b. florid subacromial bursitis
c. partial thickness supraspinatous tear
d. HADD
*LW: Likely C, although B possible is felt less likely.
If was tendinosis as stated, this would be preferred option in absence of dynamic impingement manoeuvres.
(Long explanation sorry)
Clinical Hx is describing subacromial impingement.
“Subacromial impingement is a clinical syndrome of anterolateral shoulder and/or lateral upper arm pain that occurs during elevation of the arm as a mid‐range “painful arc” that, in lesions of the rotator cuff, is believed to reflect compression of the rotator cuff and/or subacromial‐subdeltoid (SA‐SD) bursa by the overlying coraco‐acromial arch.
This definition captures the key features of subacromial impingement:
■ The condition is a clinical syndrome of pain (not a static or dynamic grayscale ultrasound appearance)
■ The pain is felt in the shoulder and/or upper arm through an “arc” of mid‐range elevation of the arm
■ Pain is due to mechanical compression of the rotator cuff and/or SA‐SD bursa by the coraco‐acromial arch.
US diagnosis is usually achieved via dynamic impingement examinations, e.g. Needs test.
Additiona signs of subacromial impingement:
(a) “bunching” or fluid distension of the SA‐SD bursa lateral to the impingement point at coraco‐acromial arch
b) “bunching” of the supraspinatus tendon lateral to the impingement point at coraco‐acromial arch
(c) bulge of the coraco‐acromial ligament ;
(d) less commonly, complete “blocking” of supraspinatus tendon motion due to “migration of the humeral head upward to prevent its passage beneath the acromion”
Thus:
1) complete US tear is usually associated with chronic impingement, in the elderly.
2) Florid sub acromial bursitis is possible, but by itself is not specific.
3) Partial thickness supraspinatus tear, possible, especially according to Gartsman sub classification of Neer’s pathological class-action into Type 2B which shows partial tears in patients 25-40yrs.
4) HADD, different clinical presentation.
Previous Answer:
answer: C
A = F B = less likely C = T = partial thickness SST tear (partial tears are more painful than full thickness tears!) D = F = aching pain, not painful arc
Apley Ortho.
• Painful arc syndrome = subacute tendinosis: usually pain at 60-120 degrees of abduction
• Cuff disruption: when complete tear patient is unable to abduct the arm; when complete tear pain subsides over weeks but abduction remains absent
• Acute calcific tendinosis = aching pain
44) MRi shoulder. True
a. fluid in subldeltoid bursa is diagnostic of supraspinatous tear.
b. fluid in bicipital bursa means biceps pathology
c. magic angle affect more likely with long TE.
d. labral tear has high association with instability
ANSWER: D
A = F = a sign of SST tear, but also occurs in bursitis B = F = can occur in joint effusion C = F = less likely on longer TE sequences (T2) D = T = most labral tears occur in association with shoulder dislocation & instability
40 yo lady with 3m shoulder pain. U/S shoulder shows thickened hypo echoic supraspinatous tendon. Most likly
a. complete supraspinatous tendon tear
b. rheumatoid tendinopathy
c. partial thickness supraspinatous tear
d. traumatic tendinopathy
ANSWER: ?D. Traumatic tendinopathy ? ?? Tendon degeneration shows thickening & heterogenous echoes at US; at MRI increased signal on PD that does not increase on T2
- 40yr female with 3m shoulder pain. US shoulder shows thickened hypoechoic supraspinatus tendon. Most likely
A. Complete supraspinatus tendon tear F – defect in tendon, flattening or concavity of echogenic subdeltoid fat, subdeltoid bursal fluid, irregular GT, tendon retraction
B. Rheumatoid tendonopathy F cuff atrophy in RA
C. Paritial thickness supraspinatus tear ? F – focal thinning/defect in tendon; decreased echogenicity &thinning at tear site
D. Traumatic tendinopathy ? ?? Tendon degeneration shows thickening & heterogenous echoes at US; at MRI increased signal on PD that does not increase on T2
Rotator cuff tendinopathy
• Degenerative changes in SST• US = thickened hypoechoic tendon +/- tears• MR = thickened tendon of T1 intermediate & T2 increased signal
46) Regarding radiographs of the shoulder which is most correct?
a. Acromiohumeral distance is normally < 7mm
b. Calcification in the supraspinatus tendon are best seen in external rotation
c. Hill-Sachs lesion is best seen in external rotation
d. Rotator cuff calcification is the most common radiographic finding in impingement
ANSWER: b. Calcifications in the supraspinatus tendon are best seen in external rotation T
*LW agrees: Ca++ in supraspinatus best seen in profile over GT on AP in external rotation.
To assess infraspinatus and tires minor; internal rotation is best suited to bring the more posteriorly based muscles into profile.
- Regarding radiographs of the shoulder which is most correct?
a. Acromiohumeral distance is normally < 7mm F normally 7-14mm; if < 6mm suggests chronic rotator cuff tear
b. Calcifications in the supraspinatus tendon are best seen in external rotation T
c. Hill-Sachs lesion is best seen in external rotation F internal rotation – this defect is visualized on AP x-ray w/ arm in internal rotation & Stryker Notch view & may be missed on routine AP views (Wheeless)
d. Rotator cuff calcification is the most common radiographic finding in impingement F
Best views (radiographs)
• ER → supraspinatus +/- infraspinatus
• IR → subscapularis & teres minor +/- infraspinatus; Hill-Sachs lesion
47) AVN OF HIP, not a cause?
a. gaucher
b. SLE
c. untreated and spondylitis
d. pancreatitis
c. untreated and spondylitis
* LW: presume this means untreated ankylosing spondylitis
48) Radiation-induced bone malignancy
a. Chondrosarcoma most common radiation-induced tumour
b. 20-25 yrs average lag time of radiation-induced malignancy
c. Radiation osteitis & radiation-induced malignancy can be differentiated by change in pattern
d. Radiation osteoradionecrosis hot on bone scan
PROBABLY C:c. Radiation osteitis & radiation-induced malignancy can be differentiated by change in pattern ?F osteoradionecrosis can be extremely difficult to differentiate from recurrent tumour, although frank bone destruction in the radiation portal without a soft tissue mass is most suggestive of ORN (AJR 10). If an associated ST mass is seen, biopsy is needed. Key sign is new destructive osseous change in radiated field – can be difficult to recognise (StatDx)
- Radiation-induced bone injury/malignancy
a. Chondrosarcoma most common radiation-induced tumour F – most common benign XRT-induced tumour is osteochondroma; most common malignant tumours are osteosarcomas (90%) & fibrosarcomas/MFH, with one-third arising in pre-existing lesions (RG 1998; Dahnert)
b. 20-25 yrs average lag time of radiation-induced malignancy F average lag-time of 11-14 years, can occur from 4-42 years post XRT
c. Radiation osteitis & radiation-induced malignancy can be differentiated by change in pattern ?F osteoradionecrosis can be extremely difficult to differentiate from recurrent tumour, although frank bone destruction in the radiation portal without a soft tissue mass is most suggestive of ORN (AJR 10). If an associated ST mass is seen, biopsy is needed. Key sign is new destructive osseous change in radiated field – can be difficult to recognise (StatDx)
d. Radiation osteoradionecrosis hot on bone scan F - decreased uptake (Dahnert)Radiation necrosis is dose-dependant, with “radiation osteitis” seen at around 30 Gy and osteoradionecrosis assoicated with doses of 50 Gy or higher. Radiation osteitis is a term used to describe potentially reversible changes such as temporary cessation of growth, periostitis, bone sclerosis and increased fragility, ischemic necrosis and infection.
Radiographs will show bone which is mottled demonstrating both osteopenia and sclerosis and areas of coarse trabeculation. Some investigators and clinicians believe that radiation osteitis is the set-up for osteoradionecrosis and that a patient does not progress to necrosis unless infection is present. [http://uwmsk.org/residentprojects/radiationchanges.html].
49) MRI and ACL injuries, which is false:
a. Meniscocapsular separation of the posterior horn of the medial meniscus
b. Bone contusion of the posterolateral tibial plateau
c. Iliotibial band avulsion
d. Bone contusion anterior aspect of the medial femoral condyle
e. Posterior horn medial meniscus tear
ANSWER: d. Bone contusion anterior aspect of the medial femoral condyle . -> should be posterior aspect medial femoral condyle in countercoup injury.
*LW: Out of all options this is probably least correct.
a. Meniscocapsular separation of the posterior horn of the medial meniscus T meniscocapular separation assoc/ w/ ACL &/or MCL tears. Sagittal T2 shows widening of meniscocapsular interval ≥ 5mm. Most common at posterior horn MM (StatDx).
b. Bone contusion of the posterolateral tibial plateau T standard is posterolateral corner tibia, lateral femoral condyle +/- posteromedial tibial condyle
c. Iliotibial band avulsion T Gerdy tubercle avulsion (anterolateral tibial plateau), RG 08. Some say Segond fracture is ITB avulsion.
d. Bone contusion anterior aspect of the medial femoral condyle ?F usually lateral femoral condyle, but can occur in anterior condyles following hyperextension injury
e. Posterior horn medial meniscus tear ?T (LM torn > MM)
* LW: Still possible, so hence can be associated with ACL injury: In acute ACl injury lateral meniscal tear > > than medial, while in chronic ACL injury, both medial and lateral occur near similar frequency. Conversely, Lateral meniscal tear was commonly associated with acute ACL injury, while medial meniscal tear with chronic ACL injury. (https://www.ncbi.nlm.nih.gov/pubmed/26286641)
* O’Donoghue’s unhappy triad = ACL tear, MM tear and MCL tear. Agree with above comments regarding lateral being more common though (lateral joint gets squashed in pivot-shift)
f. ? Concavity of the anterior ligamentous border
Associated abnormalities – ACL tear (StatDx) • Marrow oedema/contusions: o Posterolateral corner tibia o Lateral femoral condyle o +/- posteromedial tibial condyle • Bone trabecular injuries or impaction fractures of the posterolateral tibia and weight-bearing surface of lateral femoral condyle (sulcus) • Meniscal tears (lateral greater than medial) • Posterolateral corner injuries o Lateral collateral ligament o Arcuate ligament o Popliteus tendon o Posterolateral capsule o Popliteofibular ligament
50) 30yo male with anterior right shoulder injury. MRI arthrogram shows a contrast cleft between the anteroinferior glenoid labrum and bony glenoid margin. MOST LIKELY explanation?
a. SLAP
b. Bankart
c. Sublabral foramen
d. Buford complex
e. Perthes
ANSWER: b. Bankart T = Tear of the anteroinferior glenoid labrum with torn anterior scapular periosteum. May have an associated fracture of the anteroinferior glenoid rim.
30yo male with anterior right shoulder injury. MRI arthrogram shows a contrast cleft between the anteroinferior glenoid labrum and bony glenoid margin. MOST LIKELY explanation?
a. SLAP = F = Superior labrum tear propagating anterior and posterior to the biceps anchor
b. Bankart T = Tear of the anteroinferior glenoid labrum with torn anterior scapular periosteum. May have an associated fracture of the anteroinferior glenoid rim
.c. Sublabral foramen F = absent fixation of labrum at 1-3 o’clock
d. Buford complex F = absent anterosuperior labrum with thickened MGHL
e. Perthes = F = Detached inferior glenohumeral ligamentous complex with intact scapular periosteum, which is stripped medially.
Minimally-displaced, avulsed anteroinferior labrum; IGHL is non-displaced in neural positioning, but will displace with ABER positioning (“non-displaced Bankart”). ⇒ NB another recalled “contrast cleft b/w anteroinferior labrum & glenoid cartilage” that was “not displaced” – in this case the answer would be E PERTHES lesion.
- MRI knee, which is false?
a. Normal ACL is perpendicular to Blumenstaadts line
b. Tears of the posterior horn of the MM are more common than the anterior horn
c. The lateral facet of the patella is typically larger than the medial facet
d. Normal PCL is subject to “magic angle” effect
e. MCL and ACL disruption are associated
ANSWER:a. Normal ACL is perpendicular to Blumenstaadts line F Parallel
- MRI knee, which is false?
a. Normal ACL is perpendicular to Blumenstaadts line F Parallela. Normal ACL is perpendicular to Blumenstaadts line F Parallel
b. Tears of the posterior horn of the MM are more common than the anterior horn T
c. The lateral facet of the patella is typically larger than the medial facet T
d. Normal PCL is subject to “magic angle” effect T In the magic angle phenomenon, increased signal intensity may be present on the upward sloping portion of the PCL on short TE images, mimicking a tear. It is present in anatomic components of the ligament oriented 55° to the main static magnetic field, along the long axis of the magnetic bore. The phenomenon can be distinguished from a true PCL tear using long TE-weighted imaging sequences. When using proton-density imaging, the artifact may persist if the TE is 20 milliseconds or less. If the abnormal signal focus persists on T2 (long TE), a true PCL abnormality is present. In knee can also occur in posterior horn of lateral meniscus
e. MCL and ACL disruption are associated T as part of O’Donoghue’s triad
- Which of the following statements regarding congenital tarsal coalition is FALSE?
a. Calcaneo-navicular coalition is readily detectable on oblique radiographs
b. The condition is bilateral in 50%
c. 90% include the talo-calcaneal or calcaneo-navicular joint
d. Talo-calcaneal coalition are best seen on axial CT
ANSWER:d. Talo-calcaneal coalition are best seen on axial CT F coronal.
- Which of the following statements regarding congenital tarsal coalition is FALSE?
a. Calcaneo-navicular coalition is readily detectable on oblique radiographs T best seen on oblique view as direct connection (bony coalition) or close proximity & irregularity of the joint margins (fibrous coalition)
b. The condition is bilateral in 50% T bilateral in 50%
c. 90% include the talo-calcaneal or calcaneo-navicular joint T
d. Talo-calcaneal coalition are best seen on axial CT F coronal.
e. Calc-nav coalition is best visualised on sagittal T2W MRI. T calcaneonavicular coalitions best visualized on sagittal & axial MRI imageshttp://radiographics.rsna.org/content/20/2/321.full (tarsal coalition RG 2000 – direct from)
- Which of the following statements regarding cortical desmoids is MOST correct?
a. Occur only on the posterior medial epicondyle of the femur
b. Occur only on the posterior lateral epicondyle of the femur
c. Occur on the posterior cortex of the
d. They do not exhibit periosteal new bone
e. Biopsy is the only certain method of diagnosis
Cortical desmoid is a benign shallow cortical irregularity seen in older children or adolescents. It is recognised at specific metaphyseal sites, the most common being the medial posterior aspect of the distal femoral metaphysis at the insertion of the adductor magnus aponeurosis.
- Pediatric foot, which of the following statements is incorrect?
a. ‘Talipes’ refers to congenital foot deformity
b. ‘Pes’ refers to acquired foot deformity
c. Valgus refers to distal foot angulation medially
d. ‘Equinus’ refers to plantar flexion of the calcaneus
e. ‘Clubfoot’ refers to Talipes equinovarus
ANSWER:c. Valgus refers to distal foot angulation medially F = valgus means lateral angulation
- Pediatric foot, which of the following statements is incorrect?
a. ‘Talipes’ refers to congenital foot deformity T
b. ‘Pes’ refers to acquired foot deformity ??T (pes = foot)
c. Valgus refers to distal foot angulation medially F = valgus means lateral angulation
d. ‘Equinus’ refers to plantar flexion of the calcaneus T
e. ‘Clubfoot’ refers to Talipes equinovarus T
- 8yo boy presents to DEM complaining of severe pain after a fall while playing soccer. On examination – marked pain and swelling over wrist. Xrays of wrist, which is the LEAST common expected radiographic finding?
a. Fracture of the scaphoid waist
b. Fracture of the ulnar styloid process
c. Salter Harris 2 fracture of the distal radius
d. Dislocation of the distal radio-ulnar joint
ANSWER:a. Fracture of the scaphoid waist F uncommon at this age.
- 8yo boy presents to DEM complaining of severe pain after a fall while playing soccer. On examination – marked pain and swelling over wrist. Xrays of wrist, which is the least common expected radiographic finding?
a. Fracture of the scaphoid waist F uncommon at this age.
b. Fracture of the ulnar styloid process
c. Salter Harris 2 fracture of the distal radius
d. Dislocation of the distal radio-ulnar joint
Paediatric fractures about the wrist (Donnelly & Handbook of Fractures)
• Most common fracture site in children
• Most fractures of the distal forearm are buckle or transverse fractures of the distal radial metaphysis +/- fracture of the distal ulnar metaphysis
• The distal radius is the most common area of physeal (SH) fracture (28% of physeal injuries occur in the distal radius)
• Carpal injuries are very rare before the teenage years (injury force transmitted to distal radial physis rather than carpus). Injuries to the scaphoid are extremely rare in the 1st decade.Rule of thumb – wrist fractures
• 5 years = torus
• 15 years = Salter-Harris of DR
• 25 years = scaphoid #
• 45 years = Colles #
- Which of the following is LEAST LIKELY to be present in association with lateral patella dislocation?
a. Patella alta
b. Posterolateral corner injury
c. Bone oedema in the lateral femoral condyle
d. Bone oedema in the medipatella
e. Hemarthrosis
b. Posterolateral corner injury
- A 64 yo woman sees her GP with an 8 month history of bony pain. Investigations indicate hyperparathyroidism. The GP contacts you for advice regarding the next most appropriate investigation?
a. US and sestamibi scan
b. Thyroid and neck US
c. Parathyroid sestamibi
d. Surgical neck exploration
e. CT neck and chest
ANSWER:a. US and sestamibi scan T if primary hyperparathyroidism & minimally-invasive surgery considered.
- A 64yo woman sees her GP with an 8 month history of bony pain. Investigations indicate hyperparathyroidism. The GP contacts you for advice regarding the next most appropriate investigation?ANSWER:
a. US and sestamibi scan T if primary hyperparathyroidism & minimally-invasive surgery considered
b. Thyroid and neck US
c. Parathyroid sestamibi
d. Surgical neck exploration T if minimally-invasive surgery not being considered
e. CT neck and chest
WA Imaging Pathways
• Imaging for pre-operative localisation of the parathyroid glands remains controversial although it is generally recommended for minimally invasive or unilateral neck surgery.
• Ultrasound and Sestamibi scans are sensitive methods used as first line investigations, frequently in combination.
• CT and MRI have the advantage of superior anatomical localisation but are usually reserved for equivocal or negative ultrasound and nuclear medicine studies
.• Preoperative imaging is required for recurrent or persistent hyperparathyroidism to minimise the risks of repeat surgery and to maximise the chances of succesful treatment.
- 65yo female. Acute onset knee pain after walking dog. MRI obtained within 1 week later demonstrates intense marrow oedema in the medial femoral condyle. Which of the following is the MOST LIKELY associated MRI finding?
a. Displaced bucket handle tear of the medial meniscus
b. Medial collateral ligament tear
c. Radial tear medial meniscus
d. Large chondral defect
e. Intra-articular loose body
ANSWER: NOT SURE PROBABLY D:
Large chondral defect ?T with subchondral insufficiency fracture (SONK), however with this condition the overlying articular cartilage is often intact
- 65yo female. Acute onset knee pain after walking dog. MRI obtained within 1 week later demonstrates intense marrow oedema in the medial femoral condyle. Which of the following is the MOST LIKELY associated MRI finding?
a. Displaced bucket handle tear of the medial meniscus F usually adolescents & young active adults
b. Medial collateral ligament tear F would cause lateral knee contusions
c. Radial tear medial meniscus ?T middle-aged to older adult; often caused by acute trauma with axial loading; large radial tears may be a/w marrow oedema
d. Large chondral defect ?T with subchondral insufficiency fracture (SONK), however with this condition the overlying articular cartilage is often intact
e. Intra-articular loose body
- Which of the following is NOT associated with ACL tears?
a. Bone contusion postero-lat tibial plateau
b. Bone contusion at anterior aspect of med femoral condyle
c. Meniscocapsular separation of the posterior horn of MM
d. MCL injury
e. Ilio-tibial band avulsion
ANSWER:b. Bone contusion anterior aspect of the medial femoral condyle ?F usually lateral femoral condyle; bone contusions can occur in anterior condyles following hyperextension injury
- Which of the following is NOT associated with ACL tears?
a. Bone contusion of the posterolateral tibial plateau T standard is posterolateral corner tibia, lateral femoral condyle +/- posteromedial tibial condyle
b. Bone contusion anterior aspect of the medial femoral condyle ?F usually lateral femoral condyle; bone contusions can occur in anterior condyles following hyperextension injury
c. Meniscocapsular separation of the posterior horn of the medial meniscus T meniscocapular separation assoc/ w/ ACL &/or MCL tears (StatDx)
d. MCL injury T (although LM torn > MM)
e. Ilio-tibial band avulsion T Gerdy tubercle avulsion (anterolateral tibial plateau), RG 08.
Some say Segond fracture is ITB avulsion – StatDx says Segond fracture is avulsion of lateral capsular ligament at lateral tibial rim cortex, which can involve ITB more anteriorly.
Associated abnormalities – ACL tear (StatDx )• Marrow oedema/contusions: o Posterolateral corner tibia o Lateral femoral condyle o +/- posteromedial tibial condyle • Bone trabecular injuries or impaction fractures of the posterolateral tibia and weight-bearing surface of lateral femoral condyle (sulcus) • Meniscal tears (lateral greater than medial) • Posterolateral corner injuries o Lateral collateral ligament o Arcuate ligament o Popliteus tendon o Posterolateral capsule o Popliteofibular ligament
Imaging 2003
There are a number of associated injuries involving other structures which are quite specific for ACL tear. At the time of injury there is usually valgus strain, external rotation and anterior translation of the tibia relative to the femoral condyle which frequently results in an impaction injury of the posterior lip of the lateral tibial plateau against the femoral condyle [7]. The typical appearance of this injury on MRI is oedema in the posterior portion of the plateau, occasionally accompanied by a small fracture of the posterior lip, and a focal osteochondral impaction fracture of the mid portion of the lateral femoral condyle (Figure 13 ). The latter may result in a loose body. The combination of these two injuries is diagnostic of ACL tear. Similar bony impaction may be seen on the medial side which is thought to be as result of rebound from the valgus force [8]. There are often associated meniscal tears, the most characteristic of which is a vertical circumferential tear of the posterior third of the lateral meniscus.
- Which of the following findings best correlates with osteomyelitis in the setting of Charcot foot?
a. Intraarticular bodies
b. Sinus tract in bone
c. Subchondral cysts
d. Thin rim of enhancement in relation to joint effusion
e. Joint effusion
b. Sinus tract in bone T
- Which is not a feature of rickets?
a. Scoliosis
b. Fraying and cupping of metaphyses
c. Dental abnormalities
d. Premature closure of anterior fontanels
e. Genu valgus
ANSWER:d. Premature closure of anterior fontanels F (often delayed closure), JAOA 2002
- Which is not a feature of rickets?
a. Scoliosis T
b. Fraying and cupping of metaphyses T
c. Dental abnormalities T
d. Premature closure of anterior fontanels F (often delayed closure), JAOA 2002
e. Genu valgus T usually genu varus (bow legs) but can be genu valgus (esp. in hypophosphataemic rickets – Wheeless, orthonet)
- 80yo female with Hx left THR 5yo ago. Left hip pain for 10 months. Mildly increased CRP / ESR. Xray shows periprosthetic sclerosis and lucency. Bone scan shows increased tracer uptake around femoral component of prosthesis. Infection vs loosening, best investigation is?
a. Repeat bone scan 3/12 following antibiotic therapy
b. Left hip arthrography and aspiration
c. Contrast enhanced hip MRI
d. CT hip
e. Radioisotope labelled white cell scan or Gallium scan.
ANSWER:b. Left hip arthrography and aspiration T
Most diagnostic
**LJS - aspiration yes but ?not arthogram. Would be USS guided aspiration only, without imaging of joint I think
Orthobullets says aspiration is diagnostic, if can’t dx on aspiration or bloods = NM scan
In-111 labelled WBC scan combined with suphur colloid is the investigation of choice in this scenario.
**expert orthopaedic SMO opinion - aspiration, but increasing evidence for NM studies (*A pre-part 2 ortho reg also agrees with this)
ADDIITIONAL INFO
e. Radioisotope labeled white cell scan or Gallium scan. F Mettler: generalized ↑ activity around hip prosthesis on MDP bone scan may be indicative of OM. A normal Gallium scan effectively excludes OM. If the Galium & MDP bone scan distributions are spatially incongruent, or if they are spatially congruent but gallium activity exceeds technetium activity, OM should be considered. An infected joint replacement is more specifically diagnosed by comparing an 111-Indium or 99mTc labeled leucocyte images with a technetium colloid marrow (substraction) scan – when there is periprosthetic leucocyte accumulation without corresponding marrow activity on the colloid images, the study is positive for infection.
- 24yo athlete. Worsening hip pain and groin pain, brought on by running, relieved by rest. Now limiting her running. GP verifies a ‘click’ over right greater trochanter on clinical examination and appropriate stress maneuvers. Plain radiographs normal. MOST LIKELY?
a. Snapping gluteus maximum
b. Femoral head AVM
c. Trochanteric bursitis
d. Osteochondritis dessicans
e. Rectus femoris tear
ANSWER:a. Snapping gluteus maximus T (see below)a. Snapping gluteus maximus T (see below)
- 24yo athelete. Worsening hip pain and groin pain, brought on by running, relieved by rest. Now limiting her running. GP verifies a ‘click’ over right greater trochanter on clinical examination and appropriate stress maneuvers. Plain radiographs normal. MOST LIKELY?
a. Snapping gluteus maximus T (see below)
b. Femoral head AVM F – no snapping
c. Trochanteric bursitis F but can occur with/as a result of the snapping hip
d. Osteochondritis dessicans F
e. Rectus femoris tear F
Apley Orthopaedics‘Snapping hip’ is a disorder in which the patient (usually a young woman) complains of the hip ‘jumping out of place, or ‘catching’, during walking. The snapping is caused by a thickened band in the gluteus maximus aponeurosis flipping over the greater trochanter. EmedicineSnapping hip syndrome is characterized by an audible snap or click that occurs in or around the hip. This syndrome is well recognized but poorly understood. Snapping hip syndrome may be due to an external cause (eg, snapping of the iliotibial band or gluteus maximus over the greater trochanter) or an internal cause (eg, snapping of the iliopsoas tendon over the iliopectineal eminence, acetabular labral tear, intra-articular loose body). Acetabular labral tears and intra-articular loose bodies are relatively uncommon causes of internal snapping hip syndrome
- 30yo male with anterior right shoulder pain. MRI arthrogram shows a contrast cleft between the anteriosuperior glenoid labrum and bony glenoid margin. MOST LIKELY explanation?
a. Buford complex
b. Labral tear
c. Sublabral foramen
d. SLAP tear
c. Sublabral foramen sublabral sulcus/recess at 12 o’clock at site of biceps tendon attachment; sublabral foramen (= sublabral hole) 2 o’clock position ⇒ the two may co-exist
- AVN of femoral head, which is TRUE?
a. Posterior position of femoral head more commonly affected than anterior portion
b. Bone changes on both side of joint occur in the majority
c. Early loss of articular cartilage
d. Subchondral lucent line in femoral head is early sign on plain radiographs
e. MRI is more sensitive for the Dx than Tc99m scintigraphy
ANSWER:e. MRI is more sensitive for the Dx than Tc99m scintigraphy T MRI 98% sensitive & 85% specific; bone scan with SPECT is 85% sensitive
- AVN of femoral head, which is TRUE?
a. Posterior position of femoral head more commonly affected than anterior portion F anterior weight bearing portion of femoral head early
b. Bone changes on both side of joint occur in the majority F AVN is not a primary articular process – joint remains intact until secondary OA occurs
c. Early loss of articular cartilage F cartilage intact until late (secondary OA
d. Subchondral lucent line in femoral head is early sign on plain radiographs F early sign is relative sclerosis of femoral head; intermediate timing for subchondral fracture line (crescent sign)
e. MRI is more sensitive for the Dx than Tc99m scintigraphy T MRI 98% sensitive & 85% specific; bone scan with SPECT is 85% sensitive
- Regarding erosive osteoarthritis, FALSE?
a. Distribution tends to be symmetrical
b. Condition characterised by synovitis superimposed on changes of degeneration
c. Tends to be hereditary
d. Predominantly affects middle aged women
e. MCP joints are most frequently affected
ANSWER:e. MCP joints are most frequently affected F identical distribution to non-inflammatory OA (distal > proximal joints, i.e. DIPJs & PIPJs)
- Regarding erosive osteoarthritis, FALSE?
a. Distribution tends to be symmetrical T
b. Condition characterised by synovitis superimposed on changes of degeneration T
c. Tends to be hereditary T some evidence in general for a role in OA
d. Predominantly affects middle aged women T? post-menopausal women (Dahnert)
e. MCP joints are most frequently affected F identical distribution to non-inflammatory OA (distal > proximal joints, i.e. DIPJs & PIPJs)
The anatomic distribution of involvement in primary osteoarthritis and erosive osteoarthritis is the same: DIP, PIP, and first CMC joints, generally with sparing of the other joints of the hand and wrist. This pattern of distribution is characteristic and, in well-established disease, differentiates osteoarthritis from inflammatory forms of arthritis such as rheumatoid arthritis, psoriatic arthritis,” and septic arthritis and from crystal-mediated forms of arthritis such as pyrophosphate arthropathy and gouty arthritis.
67.64 year old male presents with worsening back pain. Otherwise well. Normal examination. Sclerotic lesion T8 vertebral body without loss in height. The most appropriate next investigation is:
- Skeletal survey
- CT T-spine
- MRI T-spine
- Bone scan
- No further investigation required at this stage
- Bone scan - T - would evaluate if solitary / multifocal, and if active.
- 64 year old male presents with worsening back pain. Otherwise well. Normal examination. Sclerotic lesion T8 vertebral body without loss in height. The most appropriate next investigation is: (GC) answer:
- Skeletal survey - F
- CT T-spine - F - need to image whole spine, whereby MRI would give more information regarding discs etc. as other potential causes for back pain.
- MRI T-spine - F - need to image whole spine.
- Bone scan - T - would evaluate if solitary / multifocal, and if active.
- No further investigation required at this stage - F - at least check PSA.
Bone tumours favouring vertebral bodies:
CALL HOME
Chordoma, ABC, Leukaemia, Lymphoma, Haemangioma, Osteoid osteoma/Osteoblastoma, Myeloma/Mets, EG.
DDx Ivory vertebra (sclerotic vertebra)
• Infection (↓ disc space height & endplate changes)
• Metastasis (blastic) – breast, prostate, carcinoid
• Lymphoma (Hodgkin>NHL; paraspinal mass)
• Paget disease (trabeculated)
• Mastocytosis (small bowel thickening; hepatosplenomegaly)
• Haemangioma (trabeculated)
• Vertebroplasty
Ddx widespread sclerotic lesions: metastases - prostate, (breast), lung, bladder, pancreas, stomach, colon, carcinoid, brain Paget's disease sarcoma myelofibrosis mastocytosis [Dahnert]
- Multiple crush fractures in a patient with known osteopenia. Pain. The fractures at T8 and T11 levels are hot on a bone scan. Which of the following is the most correct explanation
- Acute or malunited fractures
- Metastases
- Lymphoma
- Myeloma
- Healed fractures
- Acute or malunited fractures - hot on all 3 phases
- Multiple crush fractures in a patient with known osteopenia. Pain. The fractures at T8 and T11 levels are hot on a bone scan. Which of the following is the most correct explanation (TW/SK) answer:
- Acute or malunited fractures - hot on all 3 phases
- Metastases – could be pathologic fractures; most mets show increased uptake
- Lymphoma – lymphoma does have increased uptake +/- central necrosis causing photopenia
- Myeloma – F – positive in 75% of patients & 24-55% of sites (Dahnert)
- Healed fractures
Hot bone lesions:: Infection, Neoplasm, Trauma, autoimmune Arthropathy (e.g. Charcot), , Aseptic Necrosis
Fracture on bone scan (Mettler p270)
• Hot at 1-3 days
• Returns to normal usually by 1 year, may take 3 years
Emedicine: Myeloma is a disease that results in overactivity of osteoclasts, with resultant liberation of bone and suppression of osteoblasts. Nuclear medicine bone scans rely on osteoblastic activity (bone formation) for diagnosis. As such, standard technetium-99m (99m Tc) bone scans have underestimated the extent and severity of disease and should not be used routinely.[20]
- Which of the following is false regarding SLE?
- Erosions
- Calcification of the periarticular soft tissues
- Subluxation
- Juxta-articular osteoporosis
- Osteonecrosis
answer: 1.Erosions - F - subluxation and/or dislocation without erosive disease is the hallmark of SLE
3. Which of the following is false regarding SLE? (TW)
1. Erosions - F - subluxation and/or dislocation without erosive disease is the hallmark of SLE
2. Calcification of the periarticular soft tissues - T - calcification may be present in the subcutaneous tissue in SLE. (MSK Req – 10%, linear/streaky/nodular/amorphous)
3. Subluxation - T - see 1.
4. Juxta-articular osteoporosis - T
5. Osteonecrosis - T - said to occur in 6-40% of pts with SLE. Usually occurs bilaterally and asymetrically. Femoral heads, humeral heads, femoral condyles, and tibial plateaus, and tali are most common sites.
70.Which of the following is false regarding chordomas?
- Spinal metastases
- Destructive lesion with soft tissue
- Less than 30 years old
- Occurs in both ends of the spine
*LW:
Assuming spinal means osseous spine mets, then preferred answer is C - less than 30yrs old, given the majority occur in patients 30-70yrs
Previous answer:
answer:1.Spinal metastases – T - metastases (in 5-43%) to liver, lung, bone, regional lymph node, peritoneum, skin (late) heart.SK – depends what “spinal means” – with chordoma can get intradural extramedullary & bony metastases, but spinal cord metastases extremely rare
- Which of the following is false regarding chordomas? (TW/SK) answer:
- Spinal metastases – T - metastases (in 5-43%) to liver, lung, bone, regional lymph node, peritoneum, skin (late) heart.SK – depends what “spinal means” – with chordoma can get intradural extramedullary & bony metastases, but spinal cord metastases extremely rare
- Destructive lesion with soft tissue - T - lobulated tumor contained within pseudocapsule. Most frequent radiographic appearance of chordoma is that of a destructuve lesion of a vertebral body centered in the midline, with a large, associated soft tissue mass. SK lytic, destructive lesion – may involve disc, contiguous vertebrae, epidural space, etc.
- Less than 30 years old – F?? - can occur at any age, but mainly 30-70yo (mean 50yo). M>F 2:1. SK – StatDx = generally > 30 years, extremely rare in patients < 20 yrs; < 5% of chordomas present in childhood; young patients tend to occur in clivus
- Occurs in both ends of the spine - T - 50% in sacrum, 35% in clivus, 15% in vertebrae. Chordoma is the most common primary malignant tumor of the spine in adults excluding lymphproliferative neoplasms. Originates from embryonic remnants of notochord / ectopi cordal foci (Hensens node / primitive knot). Histo - cords & clusters of large bubblelike vacuolated (physaliferous) cells.
71.Which of the following is more suggestive of tuberculous rather than pyogenic infection of the spine?
- Multifocal
- Low signal on T1 and T2
- Disc space narrowing
- Subligamentous spread
- Normal chest xray rules it out
answer: 4.Subligamentous spread - T - infection spreads beneath the ALL or PLL to adjacent vertebrae; may see skip lesions. Pyogenic infection spreads contiguously involving disc and subchondral bone; begins in disc in kids (highly vascularised); in adults begins in endplate with secondary disc invovlement.
5. Which of the following is more suggestive of tuberculous rather than pyogenic infection of the spine? (GC) Primer p586, MSK Req p558
1. Multifocal - F - In TB there is typically more than one (up to 5-10) vertebrae involved due to subligamentous spread; upper lumber + lower thoracic (L1 most common). Pyogenic infection may involve multiple levels in 20% (esp. immunocompromised).
2. Low signal on T1 and T2 - F - non discriminating feature of spondylitis - low SI of marrow on T1, contrast enhancement of marrow +/- disc, high SI of disc (+/- marrow) on T2.
3. Disc space narrowing - F - relative preservation of disc space because TB lacks proteolytic enzymes; disc itself is preserved but fragmented (cf. rapid destruction in pyogenic infection).
4. Subligamentous spread - T - infection spreads beneath the ALL or PLL to adjacent vertebrae; may see skip lesions. Pyogenic infection spreads contiguously involving disc and subchondral bone; begins in disc in kids (highly vascularised); in adults begins in endplate with secondary disc invovlement.
5. Normal chest xray rules it out - F - no pulmonary lesions in 50%. Other features of TB spondylitis: almost always bone destruction evident at the time of imaging, rather than just marrow oedema gibbus deformity due to preferential anterior involvement in adults posterior elements often involvedepidural and paraspinous abscesses are common and large at time of presentation; psoas abscess may be calcified absence of reactive sclerosis or periosteal reaction vertebra plana in kids; vertebra within a vertebra, ivory vertebra [Dahnert; Kaplan; Castillo’s notes] Changed option 3 from “disc space narrowing/involvement late” so only one true answer.
- Regarding a destructive sacral lesion, the least likely cause would be:
- Osteoblastoma
- Giant cell tumour
- Chordoma
- Chondrosarcarcoma
answer:
- Osteoblastoma - rarely found in sacrum (Dahnert – very rare). May be blastic (large osteoid osteoma) or expansile & lytic (similar to ABC). Tends involve the posterior vertebral elements.
* LW statDx states 15-20% osteoblastomas in sacrum, tend to be young 2nd-3rd decade, thus if age was in question stem this would likely confirm this as the least likely cause. - Regarding a destructive sacral lesion, the least likely cause would be: (GC)
- Osteoblastoma - rarely found in sacrum (Dahnert – very rare). May be blastic (large osteoid osteoma) or expansile & lytic (similar to ABC). Tends involve the posterior vertebral elements.
- Giant cell tumour - T - only 7% of GCTs involve the spine, but with respect to spinal involvement, the sacrum is the most common site. 2nd-4th decade. Locally aggressive, eccentric; involves subchondral bone, may grow across SIJ. 5-10% are malignant. SK – usually no mineralisation (purely lytic); heterogeneous due to haemorrhage, necrosis and fibrous tissue.; 2nd most common primary sacral tumour after chordoma; locally aggressive;
- Chordoma - T - arise from notochordal rests, therefore always midline/paramedian in relation to spine. Most common primary sacral malignancy (excl. lymphoproliferative), mostly 4th-7th decades, 50-60% in sacrum (35% in clivus). Locally aggressive, amorphous calcifications, may cross SIJ. SK - most common primary sacral malignancy; > 70% have intratumoural calcification; T1 & T2 hetero; 70% in sacrum have T2 low signal foci of haemosiderin.
- Chondrosarcoma - T - lytic lesion with assocd soft tissue mass and calcifications; adults. Will have chondroid matrix calcification.
- Plasmacytoma - T lytic, destructive lesions
Differential for destructive sacral lesion:- tumour: -> chordoma (1st), GCT (2nd), –> met, myeloma, lymphoma, leukaemia-> ewing, neuroblastoma- infection
- Which of the following is the least specific regarding atlanto-occipital instability?
- Occipital condyle fracture
- > 12mm basion dens distance
- > 12mm distance from basion to posterior axial line
- Extradural haemorrhae along the anterior aspect of the spinal canal
- Flexion/extension views and survival of the fittest!
- LW: per same question with LJS detailed logic, in the setting of trauma, flexion extension views are least specific.
answer: 4.Extradural haemorrhae along the anterior aspect of the spinal canal
7. Which of the following is the least specific regarding atlanto-occipital instability? (GC)
1. Occipital condylar fracture - T - classified as impaction fractures, extensions of occipital skull fractures or avulsion fractures at the insertion of the alar ligaments. The latter are potentially unstable fractures, esp. if displaced, and when assocd with tectorial memebrane injury can result in gross atlanto-occipital discontinuity. May be unilateral or bilateral, may extend in a ringlike pattern around the foramen magnum, and are extemely difficult to identify on xray. May have a lower CN palsy (most commonly CNXII due to fracture extension into hypoglossal canal).
2. >12mm basion-dens distance - T
3. >12mm distance from basion to posterior axial line - T - anteriorly, see below.
4. Extradural haemorrhage along the anterior aspect of the spinal canal - non specific.
5. Flexion / extension views and survival of the fittest! - T
Normal dimensions of the CC junction at lateral xray:
Basion-dens interval <12mm
Basion-posterior axial line interval <12mm posterior to basion; <4mm anterior to basion
Prevertebral soft tissues <6mm at C2, flat or concave
Anterior atlanto-dens interval <2mm
Lateral atlanto-dens interval <2-3mm side-to-side difference
Atlanto-occipital articulation 1-2mm
Atlantoaxial articulation 2-3mm
[Radiologic spectrum of CC distraction injuries, RG 2000]
- 40 year old male with lower back pain. Xray shows a destructive sacral lesion. Which of the following is the least correct possibility?
- Chordoma
- Plasmacytoma
- Giant cell tumour
- Chondrosarcoma
- Osteoblastoma
- 40 year old male with lower back pain. Xray shows a destructive sacral lesion. Which of the following is the least correct possibility? (GC) see question 33.
- Chordoma - T
- Plasmacytoma - T
- Giant cell tumour - T
- Chondrosarcoma - T
- Osteoblastoma - F - rarely found in sacrum.
* LW: 15-20% of osteoblastomas occur in sacrum, however 90% occurr in teenagers - 20s, thus wrong age group.
Sacral destructive lesion- chordoma, GCT- met myeloma lymphoma- infection
- Which of the following is the most correct regarding rheumatoid arthritis?
- 20-40 peak age
- Osteopenia early in the course of the disease
- Pleural effusion late in the course of the disease
- Synovial tendon sheath spared
- Plain xray superior to MRI for detection of erosion defects
ANSWER:2.Osteopenia early in the course of the disease - T - early xray signs include fusiform soft tissue swelling, periarticular osteopaenia, widened joint space, subcortical cysts. Earliest changes are seen in MCP 2+3 and PIP 3; first erosion is classically the base of the proximal 4th phalanx (bare area).
- Which of the following is the most correct regarding rheumatoid arthritis? (GC)
- 20-40 peak age - F - affects 1% of population; 40-70yo. (5th to 8th decade). Females 3:1 if <40yo. (after 40, M=F).
- Osteopenia early in the course of the disease - T - early xray signs include fusiform soft tissue swelling, periarticular osteopaenia, widened joint space, subcortical cysts. Earliest changes are seen in MCP 2+3 and PIP 3; first erosion is classically the base of the proximal 4th phalanx (bare area).
- Pleural effusion late in the course of the disease - F - mostly unilateral, without change for months, usually not assocd with parenchymal disease.
- Synovial tendon sheath spared - F - tenosynovitis causes subluxations and rupture.
- Plain xray superior to MRI for detection of erosion defects - F - MR & US are the methods of choice in detecting early RA: synovial hyperaemia, synovial swelling, pannus, pre-erosive subcortical cysts, joint effusion, marrow oedema.
- Which of the following is more suggestive of a Charcot joint than osteomyelitis?
- Intraarticular loose body
- Sinus tract to bone
- Subchondral cyst
- Joint effusion
- Thin rim enhancement of fluid collection
ANSWER:1.Intraarticular loose body - T - six D’s: dense, degeneration, destruction, deformity, debris, dislocation. Loose bodies due to fragmentation of eburnated subchondral bone. Extensive osseous fragmentation is not an expected imaging finding in typical bacterial vertebral OM. The only thing that could potentially resemble a loose body in OM would be a sequestrum that may have fallen out of its cloaca…?
- Which of the following is more suggestive of a Charcot joint than osteomyelitis? (GC, TW)
- Intraarticular loose body - T - six D’s: dense, degeneration, destruction, deformity, debris, dislocation. Loose bodies due to fragmentation of eburnated subchondral bone. Extensive osseous fragmentation is not an expected imaging finding in typical bacterial vertebral OM. The only thing that could potentially resemble a loose body in OM would be a sequestrum that may have fallen out of its cloaca…?
- Sinus tract to bone - F - suggests OM.
- Subchondral cyst - F
- Joint effusion - T (but prob not most correct) - a persistent joint effusion is often the first sign of Charcot’s; joint distension may later occur due to fluid, hypertrophic synovitis, osteophytes, subluxation. Joint effusion can be seen in OM if infection spreads to joint (septic arthritis); usually involves a single joint.
- Thin rim enhancement of fluid collection - F - abscess, non-specific.
- Which of the following is the least correct regarding osteoarthritis?
- Reduced mineralization
- Erosions
- Unilateral / asymmetrical
- Subluxation
- Osteophytes
ANSWER:1.Reduced mineralization - F - bone density preserved; others include psoriasis, charcot’s, gout/pseudogout, sarcoidosis.
- Which of the following is the least correct regarding osteoarthritis? (GC/SK)
- Reduced mineralization - F - bone density preserved; others include psoriasis, charcot’s, gout/pseudogout, sarcoidosis.
- Erosions - T - may see erosions of SIJ, AC, TMJ, symphysis pubis (“SATS”). SK: Erosions occur in erosive OA. Erosions can occur in the “letter joints”, i.e. TMJ, AC & SI joints + the symph (Helms).
- Unilateral / asymmetrical - T - unilateral and/or bilateral asymmetrical distribution.
- Subluxation - T - eg. radial subluxation of 1st MC base, superolateral subluxation of femoral head (Dahnert)
- Osteophytes - T - at articular margin / non stressed area. Other OA features: nonuniform loss of joint space; subchondral sclerosis and cysts; distribution in hands, feet, knees, and hips; sparing of shoulders and elbows.[B&H, pg1133]
78.Regarding lumbar discs, which is the most correct?
- Annular tear is secondary to trauma
- Focal herniation < 25% of the disc
- Broad-based herniation >50% of the disc
- Far lateral disc at L4/5 level affects L5 nerve
- Posterolateral disc (paracentral) at L3/4 level affects L3 nerve
ANSWER:2.Focal herniation < 25% - T - localised herniation in the axial plane can be focal, ie less than 25% of the disk circumference or broad-based, meaning between 25 and 50% of the circumference. If it is >50% it is considered bulging, not herniation
- Regarding lumbar discs, which is the most correct? (JS)
- Annular tear is secondary to trauma - F - Disruption of concentric collagenous fibers comprising the anulus fibrosus. Abnormal signal focus (HIZ) at posterior disc margin on MRI. Direct association with disc degeneration, often due to repetitive trauma.
- Focal herniation < 25% - T - localised herniation in the axial plane can be focal, ie less than 25% of the disk circumference or broad-based, meaning between 25 and 50% of the circumference. If it is >50% it is considered bulging, not herniation
- Broad-based herniation >50% - F - see above
- Far lateral disc at L4/5 level affects L5 nerve - F - affects the L4 nerve which has already exited
- Posterolateral disc at L3/4 level affects L3 nerve - F - affects the L4 nerve root in the lateral recess
79.Male with anterior shoulder pain. MR arthrogram shows cleft between anterior superior labrum and bony glenoid margin. Which of the following is the most correct?
- Buford complex
- Bankart lesion
- SLAP lesion
- Superior labral foramen
- Perthe’s
*LW:
Based on stem info, i.e. just anterosuperior labrum cleft, and not stating extension posteriorly (beyond biceps insertion), I would favor this to represent a Superior labral foramen normal variant.
**LJS agree. *AJL also agree
Previous answer
SLAP LESION
- Male with anterior shoulder pain. MR arthrogram shows cleft between anterior superior labrum and bony glenoid margin. Which of the following is the most correct? (JS)
- Buford complex - Anatomical variant with absent anterosuperior labrum associated with a thickened cord like middle glenohumeral ligament. Seen in about 3% of the population.
- Bankart lesion - Refers to a complete labral tear at the origin of the inferior GH ligament, resulting in disruption of the scapular periosteum and detachment of the labrum from the glenoid rim. An osseous bankart lesion indicates an osteochondral fracture at this site
- SLAP lesion - Superior labrum anterior to posterior = seen in throwing athletes secondary to the pull of the long head of biceps which inserts into the superior labrum. A SLAP is best seen on the oblique coronal view and is irregular and extends sueriorly or laterally (cf sublabral recess which is thin and smooth and extends medially)
- Superior labral foramen - Anatomical variant which is a opening beneath the anterior superior labrum and bony glenoid that mimics a detachment. Seen in up to 20% of the population. SK: sublabral sulcus/recess at 12 o’clock at site of biceps tendon attachment; sublabral foramen (= sublabral hole) 2 o’clock position ⇒ the two may co-exist
- Perthe’s - Similar to Bankart where the inferior labral-ligamentous complex remains attached to the scapular periosteum which is stripped medially on the glenoid neck
