-
What are the characteristic radiographic findings in osteoarthritis?
Osteophytes
Sclerosis
Joint Space Narrowing
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What disorder is associated with osteophytes but no joint space narrowing or sclerosis?
DISH (Diffuse Idiopathic Skeletal Hyperostosis)
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What are the characteristic radiographic findings of rheumatoid arthritis?
Any synovial lined joint in the body:
Osteoporosis
Marginal erosions
Soft tissue swelling
Joint space narrowing
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In what direction does the joint space narrowing occur in rheumatoid arthritis in the femoral head vs osteoarthritis
Rheumatoid arthritis - In an axial direction
Osteoarthritis - superior direction (towards weight bearing)
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Syndesmophyte
Syndesmophytes run vertically while osteophytes run horizontally
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Which spondyloarthropathies tend to have syndesmophytes which are MARGINAL and SYMMETRIC?
Ankylosing Spondylosis
Inflammatory Bowel Disease
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Which spondyloarthopathies tend to have syndesmophytes which are NONMARGINAL and ASYMMETRIC?
Psoriatic arthritis
Reiter's syndrome
-
Symmetric/bilateral SI joint involvement
Ankylosing spondylitis
Inflammatory Bowel Disease
-
Unilateral/asymmetric SI joint involvement
Psoriatic arthritis
Reiter syndrome
-
What is the classic pattern of arthropathy seen in psoriatic small joint involvement?
Distal joints
Proliferative erosions
Soft tissue swelling
Periostitis
-
How long does it take for gout to manifest itself radiographically?
Takes 4 to 6 years for gout to cause radiographically evident disease
-
Erosions with SCLEROTIC margins
- Classic gout finding
-
What is the classic triad in CPPD (pseudogout)?
Pain
Cartilage calcification
Joint destruction
-
What are the classic locations for cartilage calcification (chondrocalcinosis)?
Knee (medial and lateral compartments)
Wrist (triangular fibrocartilage)
Symphysis pubis
-
What is the differential for soft tissue calcification of the rotator cuff of the shoulder?
CPPD (pseudogout)
CHA (HAD) (Hydroxyapatite deposition)
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What is the main difference between the joint destruction found in DJD versus CPPD (pseudogout)?
CPPD has a proclivity for the upper extremity
-
What disorders are highly associated with CPPD (pseudogout)?
Gout
Hyperparathyroidism
Hemachromatosis
-
What are the characteristic radiographic findings in collagen vascular diseases?
Osteoporosis
Soft tissue wasting
-
What types of hand findings are noted in patients with lupus (SLE)?
Severe ulnar deviation
-
What types of radiographic changes are found in hemachromatosis?
- Findings of DJD (joint space narrowing, sclerosis, osteophytes)
- CPPD (pseudogout)
-
What disease do these bony findings suggest?
Hemochromatosis
"Drooping" osteophytes
"Squaring" of the metacarpal heads due to large osteophytes
-
What is the most commonly seen location of a Charcot joint?
Diabetic foot
First and second tarsometatarsal joint
-
What are the classic findings for Juvenile Rheumatoid arthritis and hemophilia?
Overgrowth of the ends of bones (epiphyseal enlargement)
-
What is the pathogenesis of synovial osteochondromatosis?
Metaplasia of the synovium with deposition of foci in joint cartilage
-
What is the difference in pathophysiology between primary and secondary synovial osteochondromatosis?
Secondary synovial osteochondromatosis - small bits of cartilage shed into joint at different times, grow as they are nourished by synovial fluid > loose bodies of different sizes
-
What is pigmented villonodular synovitis?
Chronic inflammation of the synovium that causes synovial proliferation
-
What is another consideration on the differential if the deposits of cartilate do not ossify in the joint?
Noncalcified synovial osteochondromatosis
Pigmented villonodular synovitis
-
What is the most reliable radiographic sign of a knee effusion?
Distance between suprapatellar fat pad and the anterior femoral fat pad (> 10 mm)
-
What are the radiographic stages of avascular necrosis?
1. Joint effusion
2. Patchy/mottled increase in density
3. Subchondral lucency along articular surface
4. Collapse of articular surface
-
What is a smaller and more focal form of avascular necrosis?
Osteochondritis dissecans
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- Madelung deformity
- - Positive ulnar variance
- - Lateral/dorsal bowing of radius
Congenital or traumatic distubrance of distal ulnar side of epiphyseal growth plate leading to shortening of the radius and overgrowth of the ulna
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What is the mnemonic for benign lytic bone lesions?
- FEGNOMASHIC
- F - Fibrous dysplasia
- E - Enchondroma/Eosinophilic Granuloma
- G - Giant Cell Tumor
- N - Nonossifying Fibroma
- O - Osteoblastoma
- M - Metastatic disease
- A - Aneurysmal Bone Cyst
- S - Solitary Bone Cyst
- H - Hyperparathyroidism
- I - Infection
- C - Chondroblastoma/Chondromyxoid fibroma
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How can one rule out fibrous dysplasia?
Fibrous dysplasia will not have periostitis
Fibrous dysplasia looks like almost anything
Often "ground glass" appearance
-
Where does one typically find fibrous dysplasia?
Pelvis (proximal femur invariably)
Ribs
Skull
-
What else should you consider if you are considering fibrous dysplasia in the tibia?
Adamantinoma (malignant tumor)
-
What is the syndrome if one notes polyostotic (affecting more than one bone) lesions in conjunction with cafe au lait spots and precocious puberty?
McCune-Albright syndrome
-
What is the most common benign cystic lesion of the phalanges?
Enchondroma
-
What are the typical findings in an enchondroma?
Calcified chondroid matrix (except in phalanges)
No periostitis
-
- Bone infarct -
- well defined, serpentiginous, densely sclerotic border
- No endosteal scalloping
-
How to differentiate enchondroma vs Chondrosarcoma?
Pain is more commonly associated with chondrosarcoma
-
What syndrome is associated with multiple enchondromas?
Ollier's disease
-
What syndrome is associated with multiple enchondromas and soft tissue hemangiomas?
Maffucci's syndrome
-
What entities have been described to have bony sequestra?
Eosinophilic granuloma
Osteomyelitis
Lymphoma
Fibrosarcoma
-
What is the approximate age cutoff for patients with eosinophilic granuloma?
EG is much more rare in patients above 30
-
1. Closed epiphyses
2. Epiphyseal lesion abutting articular surface
3. Eccentric location
4. Sharp, non-sclerotic border
-
What is the difference between a fibrous cortical defect and a non-ossifying fibroma?
Fibrous cortical defects are typically shorter than 2 cm in length
-
What is the differential diagnosis for expansile, lytic lesions in posterior aspect of spine?
Osteoblastoma
Aneurysmal Bone Cyst
Tuberculosis
-
What types of cancers can cause expansile, lytic metastases?
Thyroid CA
Renal CA
-
Aneurysmal bone cyst - multiple fluid-fluid levels
-
What is the typical age range of an aneurysmal bone cyst?
Less than 30 years old
-
Unicameral(solitary) bone cyst
Fallen fragment sign (from fracture)
- Central location
- Proximal humerus and femur often
-
Hyperparathyroidism
Subperiosteal bone resorption - resorption of radial(lateral) aspects of proximal/middle phalanges (often 2nd/3rd)
Can also be seen in distal clavicles
-
What is the differential diagnosis for a lytic lesion in the EPIPHYSIS in a patient under age 30?
- 1. Infection (osteo)
- 2. Chondroblastoma
- 3. Giant Cell Tumor
-
What rare lesion can mimic a non-ossifying fibroma?
Chondromyxoid fibroma
-
What disease is eosinophilic granuloma a benign form of?
Langerhans Cell Histiocytosis
-
How do thalassemias affect bone?
Cause extramedullary hematopoeisis > hairy skull, thickened bone
-
-
What is the mechanism of a Jefferson fracture?
Axial loan injury leading to burst fracture of C1 (atlas) ring
-
What is the most common type of dens fracture?
Type II - fracture through base of odontoid process
-
What can structures can be injured with an MVA in which the chin hits the dashboard and causes hyperextension?
Bilateral pars interarticularis fracture
-
What is the name of the fracture in which chin strikes dashboard leading to bilateral pars interarticularis fractures?
Hangman's fracture
-
What structures can get injured with a hyperflexion injury?
Anterior compression fracture
Disruption of posterior ligament
-
What is the name of the fracture associated with severe hyperflexion injury?
Flexion teardrop fracture
-
What can be fractured with hyperflexion of the neck associated with shoveling against fixed resistance?
Spinous process
-
What is the fracture called in which the spinous process is fractured associated with hyperflexion of the neck during shoveling against fixed resistance?
Clay Shoveler's fracture
-
What is the difference in mechanism between unilateral and bilateral facet joint dislocations?
Unilateral - rotational injury
Bilateral - extreme hyperflexion
-
What fracture can occur a motor vehicle accident in which someone's back hyperflexes with a lap belt in place?
Horizontal splitting of posterior elements extending anteriorly
-
What is the difference between spondylolysis and spondylolisthesis?
Spondylolysis - defect or fracture of pars interarticularis
Spondylolisthesis - Anterior displacement of the involved vertebral body with respect to inferior vertebral body
-
What is grade II spondylolisthesis?
Displacement of 25 to 50% of the vertebral body's AP dimension
-
Jaccoud/lupus arthropathy
Non erosive
Marked ulnar subluxation at MCP joints
-
What is the major complication of multiple hereditary exostoses?
Chondrosarcoma
-
What are the characteristic imaging findings in multiple hereditary exostoses?
Widening of metaphyses
Sessile or pedunculated exostoses
-
What are characteristic MSK findings of neurofibromatosis type I?
- S-shaped scoliosis
- Posterior vertebral body scalloping
- Ribbon Ribs
- Severe bowign
- Pseudoarthroses

-
What is the primary defect in osteopetrosis?
Defective osteoclast activity
-
Sever disease - Inflammation/sclerosis of calcaneal apophyses
Often seen in young children (jumping) and is self limited
-
What is the difference between lunate and perilunate dislocation?
Perilunate dislocation > lunate maintains normal position with respect to distal radius
-
What is the difference between a trans-scaphoid perilunate dislocation and a perilunate dislocation?
Transcaphoid perilunate dislocation > includes fracture of the scaphoid
-
What are the most common tarsal bone coalitions?
Calcaneus and navicular (most common)
Talus and calcaneus
-
What nerves and muslces are typically involved in Parsonage-Turner syndrome?
Suprascapular nerve
 - Supraspinatus and infraspinatus
-
What nerves and muscles are involved with quadrilateral space syndrome?
Axillary nerve
Deltoid and teres minor
-
Particle disease -
- Multifocal lucencies
- Do not conform to prosthesis
- No associated sclerotic reaction
-
Double PCL sign - band anterior to intact PCL
Suggests bucket handle meniscal tear
-
Eccentric
Metadiaphyseal lesion
Lytic lesion, sclerotic, scalloped
Non-ossifying fibroma
-
Myositis Ossificans - peripheral calcifications in patient with history of trauma
-
What is the difference between gigantism and acromegaly?
Gigantism - stimulation of endochondral ossification before growth plate closure
Acromegaly - growth hormone hypersecretion in the skeletally mature patient leading to intramembranous bone formation resulting in periosteal new bone formation and widening of osseous structures
-
Blount disease - lack of growth of the medial proximal tibial physis
-
What is typically the first ligament to be injured in an ankle inversion?
Anterior talofibular ligament (ATFL)
-
Tug lesion - minimal smooth periosteal thickening at medial aspect of distal femur (most likely secondary to vastus medialis insertion)
-
Humeral pseudocyst - area of decreased cancellous bone in the greater tuberosity due to disuse or osteoporosis
Not a lytic lesion
-
Supracondylar process of the humerus
-
Bipartite patella
Accessory ossification center at superolateral aspect of patella
-
Os odontoideum
Unrecognized fracture through growth plate before age 6 - lack of fusion of dens
Abnormal mobility of the dens with respect to C2
-
Dysplasia Epiphysealis Hemimelica (Trevor's disease)
Osteochondromas arising from the epiphysis
-
What is the differential diagnosis for a cystic lesion of the TERMINAL phalanx?
Epidermal inclusion cyst (associated with history of trauma)
Glomus tumor
Enchondroma (rare)
-
Teenager pitcher with shoulder pain
- Little league shoulder - Salter 1 injury with widened proximal humeral lateral physis

-
Where do labral variants tend to occur?
- At the 11 to 3 o'clock position -
- Sublabral foramen
- Sublabral recess
- Buford complex
-
Luxatio erecta (inferior shoulder dislocation)
Arm appears held upward or behind head in fixed abduction.
-
Macrodystrophia lipomatosa - localized form of giantism
Usually affects 2nd or 3rd digit of hand or foot
-
Peroneus brevis split tear
C-shaped appearance around peroneus longus
-
Nail patella syndrome (Fong disease)
-
Iliotibial band syndrome
Ill-defined signal abnormality interposed between the iliotibial band and femoral condyle (low T1, high T2)
-
Jumper's knee -
Injury of proximal patellar tendon where it inserts onto inferior pole of the patella
- Pediatric form - similar to:
- Sinding-Larsen-Johansson disease
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