FRCR

Question 1

Intraosseous lipoma

Answer 1

Central calcification, possibly fat necrosis
4th and 5th decades
Intertrochanteric femur (34%), tibia (13%), fibula (10%), calcaneus (8%), ilium (8%)
Long bone involvement is usually metaphyseal
Abscence of calcification raised possibility of UBC
Treat with curettage

Question 2

Frieberg’s infraction

Answer 2

Usually 2nd metatarsal head
Unlike other AVN, not associated with normal causes - thought to be traumatic
Female 5x male, in contrast to other AVNs which have male predominance

Question 3

Pagets location and complications

Answer 3

Femur, tibia, pelvis.
In long bones, osteolysis starts subchondrally - blade of grass
OA, fracture, spinal stenosis, conduction deafness, sarcomas
Skull base - sensorineural deafness, optic atrophy, hydrocephalus (secondary to platybasia)

Question 4

Discoid meniscus - side?

Answer 4

Lateral much more common
Bilateral in 20%
May dispose to tearing
Wrisberg variant hypermobile as meniscus not attached to meniscofemoral ligament of Wrisberg

Question 5

Double line sign

Answer 5

Sign of AVN / bone infarct.

High T2 signal granulation tissue surrounded by low T2 signal sclerotic bone

Question 6

Bone infarct v AVN

Answer 6

AVN preferred for subchondral, infarct for metaphyseal and diaphyseal disease

Question 7

Bone infarct complications

Answer 7

Malignant degeneration, OA, osteochondral lesions (would tend to be called AVN for the latter ones)

Question 8

H-vertebra

Answer 8

Sickle cell, possibly also Gauchers. Represents microvascular endplate infarction (Picture frame is Pagets, Sandwich is osteopetrosis and sharper definition and denser than Rugger-Jersey spine, HPT)

Question 9

Discitis organisms and anatomy of spread

Answer 9

Adults starts in endplates, children in vascular discs, from haematogenous spread
Staph
TB - Potts
Strep viridans in IVDU, immunocompromised
E coli
Fungal and other

Typically children or >50

Question 10

Calcinosis universalis

Answer 10

Scleroderma, SLE, dermatomysositis, polymyositis, idiopathic

Long bands of symmetric calcification subcut along fascial planes

Question 11

Calcinosis circumscripta

Answer 11

Fine clustered calc, hands and feet

Raynauds, scleroderma, dermatomyostisi

Question 12

Tumoral calcinosis

Answer 12

AD familial painless periarticular calcific masses

Disordered phosphate regulation

Question 13

Beak-like osteophytes

Answer 13

From Radial heads of metacarpals. 2nd and 3rd in CPPD, 2-5 more common in haemochromatosis.
Beak like osteophytes may also occur in hip and shoulder
Chondrocalcinosis occurs in 30% of haemachromatosis patients.

Question 14

Lipoma v liposarcoma

Answer 14

Retroperitoneal is sarc til proven otherwise
Fat interdigitating with muscle is a sign of benignity
Lipoma:liposarcoma 100:1
Thin septa may be seen in lipoma
Thick septa, enhancement, nodules, incomplete fat suppression are signs of liposarcoma
Lipomas are multiple in 15%

Question 15

Haemophiliac arthropathy

Answer 15

Suspect if degenerative changes in non-weight bearing joint, or widening of intracondylar notch of the knee.

Question 16

Duchenne muscular dystrophy

Answer 16

X-linked recessive
1/3 sporadic
Pseudohypertrophy of soleus - muscles are replaced by fat
Contractures common

Question 17

Brown tumour locations

Answer 17

Facial bones, pelvis, ribs, femur

May be cortical or medullary

Question 18

HPT

Answer 18

Bone resorption
2nd and 3rd finger proximal and middle phalanges radial aspect
Rugger jersey spine
Salt and pepper skull
Brown tumours
Osteopaenia
Chondrocalcinosis
Acro-osteolysis
Subchondral bone resporption - distal clavicles, symph pub, SIJ
Subligamentous bone resorption - ischial tuberosity, trochanters, inferior calcaneus and clavicle

Question 19

Metastatic calcification

Answer 19

Most common in renal failure, but also in other conditions that raise Calcium
HPT, sarcoid, myeloma, osteolytic mets

Question 20

Gout v pseudogout, birefringence

Answer 20

Gout negatively (needle shaped crystals)
Pseudo postively (rhomboid shaped crystals)

Question 21

Hyperuricaemia

Answer 21

Primary (idiopathic) or secondary to renal disease, endocrine disease (hypothyroidism), other (Glycogen storage disease, lymphomproliferative disease)

Question 22

Gout

Answer 22

Intraosseous tophi cause the erosions

Joint spaces and bone density preserved until late

Question 23

Primary synovial osteocondromatosis

Answer 23

Stage 1 is nodules in synovium, ossify in 30%
Stage 2 is loose bodies
Stage 3 is inactive disease
Men 2:1
Tends to be monoarticular - poly in 5%
May have marginal erosions from pressure
Small risk of chondrosacromatous degeneration
May have “secondary” disease to trauma, charcot, OA.
Benign disease, synovial metaplasia, 4th-5th decade
Knee, hip, elbow, shoulder common

Question 24

PVNS, lipoma arborescens, myositis ossificans? - differential for this, and for fluid-fluid levels

Answer 24

.

Question 25

PVNS of tendon

Answer 25

= GCT of tendon sheath

Question 26

PVNS

Answer 26

``` Benign synovial neoplasm Synovial proliferation and haemosiderin deposition Erosion may occur from pressure Calcification rare Knee, hip, ankle Mostly monoartiular Vilous and nodular synovial projections - lobuted margins Low haemosiderin signal, blooming Variable enhancement 3-5 decade ```

Question 27

Up to case 18

Answer 27

.