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
- 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 scaphoid
Referring 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.
- triple sign on T2 sequences
- 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)