2. Aneurysmal Bone Cyst Findings:
expansile lytic lesion of the distal ulnar metaphysis
well-defined margins
internal septations
No periostitis
A result of trauma or tumor induced process
ddx:
Giant cell tumor
Chondroblastoma
Osteoblastoma
Fibrous Dysplasia
lytic met

4. Osteopetrosis (Marble bones, Albers- Schoenberg)
Findings:
generalized increased bone density
rare bone dysplasia
Trabecular --> compact
Anemia w/extramedullary hematopoiesis
ddx: (children)
pyknodysostosis
renal osteodystrophy
vit A, D
Lead
Fluorosis

6. Paget’s Disease Findings:
Enlargement of the right femoral head with course and thickend trabecula
Asymmetric lucency of the right superior acetabulum
ddx:
NONE!
This is an Aunt Minnie!

10. Brown Tumor Findings: expansile, lytic rib lesion
lytic lesion of 2nd PP
subperiosteal bone resorption
arterial Ca2+
Usually secondary to CRF but may be primary
check for PT adenoma
if on dialysis, check wrist for amyloid arthropathy (cysts in carpal bones)
ddx:
metastases
multiple myeloma

13. Bucket-Handle Tear Findings:
“double PCL sign” - torn meniscus BELOW normal PCL on sag view
Above ACL on cor view
Truncation of medial meniscus
Joint effusion
Medial = 3x lateral
Locked knee
ddx:
torn ACL, PCL
torn meniscus

15. Ankylosing Spondylitis
Findings:
fused SI joints
right hip erosions
lumbar syndesmophytes
Sero-negative chronic inflammatory disease
Starts in the low back and progesses upward
ddx (sacroilitis)
bilateral
ank spond
IBD
Unilateral
Reiter’s
psoriasis

18. Femoral Head AVN Findings: bilateral femoral head AVN w/o collapse
right pelvic renal tx

21. Hill-Sachs Deformity and Osseous Bankart Lesion
Findings:
Impaction fracture of the posterolateral humeral margin (Hill-Sachs)
Fracture of the osseous glenoid rim (Bankart)
secondary osteoarthritis
Related to repeated anterior dislocations (shoulder instability)
Bankart lesion is typically only of the cartilaginous labrum, best seen on MRI

24. Lateral Patellar Dislocation
Findings:
bone bruise of lateral femoral condyle and medial patella
injury of the patellar retinaculum
joint effusion
Patella usually dislocates lateral (medial facet more acute angle)
Look for constellation of findings

26. Metastatic Renal Cell Findings:
expansile lytic lesion of the distal ulnar metaphysis
well-defined margins
internal septations
No periostitis
Don’t forget about mets!
ddx:
ABC
Giant cell tumor
Chondroblastoma
Osteoblastoma
Fibrous Dysplasia

28. Homolateral Lisfranc farcture/dislocation
Findings
lateral subluxation of the second through fifth metatarsals
dislocation is relative to the cuneiforms:
homolateral
divergent (1st MT medial)
can be due to trauma or in patients with diabetic neuropathy

30. Osteochondritis Dissecans
Findings:
defect in the medial talar dome representing an osteochondral fracture
Unknown etiology but most common causes are:
trauma
osteonecrosis
Do MRI w/ or w/o arthro to look for free fragment

32. Pellegrini-Stieda disease
Findings:
Linear ossific density adjacent to the medial femoral condyle
Calcification or ossification of the MCL at its insertion site
Sequela of previous injury
NOT acute, usually not the site of pain

35. Bilateral SCFE Findings:
posteromedial displacement of femoral epiphyses
Most common cause of limp in adolescents
SH-I shearing fx
high incidence in black, overweight pubertal males
75% uni, 25% bi
Look for line along lateral femoral neck to transect 1/6th of epiphysis
Must be pinned or fixed

38. Synovial Sarcoma Findings: Dense soft tissue mass no bony involvement
heterogeneous T1
Rare soft tissue tumor of children
May show calcification
Internal hemorrhage and necrosis are common
Found close to joints
Prone to metastases
ddx: (plain film only)
hematoma

40. Unicameral Bone Cyst Findings:
lytic, slightly expansile lesion of the proximal metaphysis with a thin sclerotic margin and fracture
a.k.a. simple bone cyst
fluid-filled cavity
common lesion of children, unknown etiology
asymptomatic unless fracture (“fallen fragment sign”)

42. Melorheostosis Findings:
Peripheral hyperostosis of the tibia producing a wavy sclerotic diaphyseal contour
Rare bone disorder of childhood
“candle wax” dripping down the bone appearance
presents with PAIN and joint swelling
ddx:
Paget’s
myelofibrosis
renal osteodystrophy
sclerotic mets

44. Congenital Reubella w/patent ductus arteriosis
Findings:
cardiomegaly, enlarged pulm arteries
longitudinal striations of sclerotic and radiolucent areas at the metaphyses (“celery stalk” appearance)
epiphyseal center not seen
dense, irregular metaphyseal bands
most common viral infxn w/bone changes (also CMV)
IUGR, TTP, cataracts, sensorineural hearing loss, PDA, pulm art and Ao stenoses

47. Aneurysmal bone cyst Findings:
Lucent end of bone lesion in the proximal tibia
Slightly expansile, mild periosteal reaction
Fluid-fluid level on MRI
ddx:
Giant cell tumor
Unicameral bone cyst
Fibrous dysplasia
Chondroblastoma (rare)

49. Inferior shoulder dislocation
Findings:
Inferior dislocation of humeral head and a deep cleft in the superior portion
ddx:
Anterior dislocation

51. Dens metastasis C1-2 subluxation
Findings:
8mm anterior subluxation of C1 on C2 with flexion
Conventional tomogram shows C2/dens lytic lesion and pathologic fracture
ddx:
Rheumatoid
Dens fracture

53. C3 vertebra plana (multiple myeloma)
Findings:
Complete compression of C3 (look at the vertebral bodies and their corresponding posterior elements!)
ddx:
Metastasis
Kommel’s disease (if see gas and collapse) EG

55. Calcaneal stress fracture
Findings:
Patchy linear and arc-like sclerosis in the posterior calcaneous
ddx:
NONE!
This is an Aunt Minnie!

57. Enchondroma Findings:
Patchy sclerotic intramedullay lesion in the proximal tibial metadiaphysis
“Rings and arcs” calcification
ddx:
Enchondroma with chondrosarcomatous degeneration
Bone infarct

59. Cleidocranial dysplasia
Findings:
Absent central portion of clavicle with rudimentary medial and lateral portions
Congenital coxa vara
Widened appearance of pubis (due to delayed ossification)
ddx:
NONE!
This is an Aunt Minnie!

61. Cystercercosis Findings:
Innumerable round and oval soft tissue calcifications
ddx:
Diffuse dystrophic or metastatic calcifications

63. Giant cell tumor Findings:
Expansile lucent lesion in the fibular head containing multiple thin septa
ddx:
Aneurysmal bone cyst
Fibrous dysplasia
Lytic metastasis
Brown tumor
Chondroblastoma (rare)

65. Hypertrophic Osteoarthritis
Findings:
Diffuse symmetrical periosteal reaction of the distal radius, ulna, and tibia
ddx:
Adults
Pulmonary
Pachydermoperiostitis
Vascular insufficiency
Thyroid acropachy
Fluorosis
Peds
Caffey disease
Leukemia
Rickets
Hypervitaminosis A

67. Hyperparathyroidism Findings: “salt and pepper” skull
Osteopenia with course trabecula
Subperiosteal resorption
ddx:
NONE!
This is an Aunt Minnie!

69. Tumoral Calcinosis Findings:
Multiple dense calcifications around the joints of the fingers and wrists
ddx: (soft tissue Ca2+)
Renal osteodystrophy
Heterotopic ossification
Metastatic Ca2+
Milk-alkali syndrome
Hypervitaminosis D
Scleroderma
Dermatomyositis

71. Lymphoma Findings: Permeative lytic lesion of the humeral diaphysis
Periosteal reaction and soft tissue swelling
ddx:
Osteomyelitis
Metastasis
Ewing’s Sarcoma EG

73. Osteomalacia w/ Looser’s zone
Findings:
Osteopenia
Horizontal linear lucency in the medial femoral metaphysis
Causes:
Renal osteodystrophy
Hyperparathyroidism
Vit D deficiency
ddx:
NONE!
This is an Aunt Minnie!

75. Knee fracture Findings: Lipohemarthrosis
No visible fracture but one is definitely present
ddx:
NONE!
This is an Aunt Minnie!

77. Osteochondromatosis Findings:
Flared metaphyses due to multiple bony outgrowths = exostoses
Contiguous with cortex and medulla
Point away from joint
Look for pain (after bony maturation) – check cartilagenous cap = >2cm, risk of chondrosarcoma
ddx:
NONE!
This is an Aunt Minnie!

79. Paget’s Disease w/ sarcomatous degeneration
Findings:
Cortical thickening with mixed lytic and sclerotic trabecular pattern and bony enlargement
Large lytic lesion of the right ilium and sacral ala
ddx:
Diffuse sclerotic and lytic mets

81. Rickets Findings: Cupped and frayed metaphyses
Wide physes (increased osteoid)
Long bone bowing
Decreased bone density
ddx:
NONE!
This is an Aunt Minnie!

83. Bilateral perched lumbar facets
Findings:
Mild anterolisthesis of L4 on L5
Inferior L4 facets perched on superior L5 facets
ddx:
NONE!
This is an Aunt Minnie!

85. Rheumatoid arthritis Findings:
Destruction of the dens and the anterior C1 arch by a soft tissue mass
Impression of the anterior thecal sac with slight deformation of the cervical cord
ddx:
Infection
Metastasis

87. Septic Arthritis Findings:
Lytic and sclerotic destruction of the great toe MTP joint
Joint space narrowing
Periosteal reaction
Soft tissue swelling
ddx:
Charcot joint
Metastasis with pathologic fractures

90. Potts Disease Findings:
Complete collapse of L4 and cauda equina compression
Subligamentous soft tissue extension to L3 body
ddx:
Staph aurius
Gram negatives (IVDA)

92. Enchondroma Findings:
Lucent, slightly expansile lesion of the fifth MC
ddx:
Giant cell tumor
UBC
Fibrous dysplasia

94. Discitis
Findings:
T12-L1 disc space narrowing with endplate destruction
CT demonstrates presence of gas
ddx:
NONE!
This is an Aunt Minnie!

96. Right hip synovitis Findings:
Asymmetric teardrop distance (greater on right)
Normal joint space
ddx:
Infection
Rheumatoid

98. Osteogenesis Imperfecta Type II
Findings:
multiple fractures, bowing and short ribbon-like bones
Type II - lethal - “ribbon bones” and fractures too numerous to count
Disturbances in type I collagen
lack of normal collagen
osteoperosis
fractures
blue sclera
ddx:
NONE!
This is an Aunt Minnie!

100. Polyostotic fibrous dysplasia
Findings:
Multiple lucent and expansile lesions
“ground glass matrix”
May be seen on precocious puberty – McCune Albright syndrom
ddx:
Multiple enchondromas

102. Renal osteodystrophy Findings: Osteopenia Prominent trabecular pattern
“rugger jersey” spine
ddx:
NONE!
This is an Aunt Minnie!

104. Eosinophilic Granuloma
Findings:
Well-defined lytic lesion in the frontal skull crossing the diploic space
Overlying scalp swelling
Positive bone scan
ddx:
Osteomyelitis
Metastasis

106. Prostate metastases Findings: Diffuse sclerosis ddx: Breat, GI mets
myelofibrosis
renal osteodystrophy
osteopetrosis
multiple myeloma

108. Surpacondylar Process of the Humerus
Findings:
large osseous projection originating from mid humerus and extending inferiorly into the arm
Normal anatomic variant
May cause median nerve compression
ddx:
NONE!
This is an Aunt Minnie!