Radiology Notes

My notes during radiology residency, fellowship, and beyond…

Archive for June 2008

Don’t Touch Lesions

leave a comment »

Postraumatic

  • myositis ossificans
  • avulsion injury
  • cortical desmoid
  • degenerative geodes
  • discoid vertebral sclerosis
  • healing fracture callus
  • pseudodislocation of the humerous (fracture and hemarthrosis)

Normal Variants

  • dorsal (articular) lucent defect of patella
  • pseudocyst of humerus
  • os odontoideum

Benign Lesions

  • Nonossifying fibroma
  • bone islands
  • unicameral bone cyst
  • bone infarction

Written by lmwong

June 20, 2008 at 4:15 pm

Posted in bone, differential, msk

Bowing deformity

leave a comment »

  • traumatic injury to radius and ulna without fracture
  • if untreated, pronation and supination reduced
  • must be broken and reset

Written by lmwong

June 19, 2008 at 2:47 pm

Galeazzi’s fracture

leave a comment »

fractured distal RADIUS with dislocation of distal ulna

Written by lmwong

June 19, 2008 at 2:45 pm

Posted in bone, fracture, msk, wrist

Monteggia’s fracture

leave a comment »

fracture of ULNA with dislocation of radial head

Written by lmwong

June 19, 2008 at 2:43 pm

Posted in bone, elbow, fracture, msk

Barton’s fracture

with 2 comments

  • intra-articular radial fracture
  • dorsal angulation
  • plus radiocarpal dislocation
  • see Colles’ fracture

Written by lmwong

June 19, 2008 at 2:40 pm

Posted in bone, fracture, msk, wrist

Smith fracture

leave a comment »

Written by lmwong

June 19, 2008 at 2:38 pm

Posted in bone, fracture, msk, wrist

Colles’ fracture

leave a comment »

  • fall on outstretched hand
  • fracture of distal radius and ulna with dorsal angulation
  • metaphyseal, epiphyseal region
  • see Frykman classification
  • opposite of Smith fracture
  • see Barton’s fracture (+dislocation)

Written by lmwong

June 19, 2008 at 2:34 pm

Posted in bone, fracture, msk, wrist

Triquetrial fracture

leave a comment »

Avulsed fragment on lateral view

Written by lmwong

June 19, 2008 at 2:28 pm

Posted in bone, fracture, msk, wrist

Fracture of scaphoid

leave a comment »

  • High potential for AVN to the proximal fragement (blood supply begins distally)
  • Trauma with pain over the snuff box
  • If high clinical suspicion and negative film, cast and refilm in 1 week:
  1. Diffuse osteopenia and hyperemia around the fracture site
  2. Or just get MRI
  • AVN = increased density of proximal pole of scaphoid

Written by lmwong

June 19, 2008 at 2:26 pm

Posted in bone, fracture, msk, wrist

Rotary subluxation of the scaphoid

leave a comment »

  • rupture of scapholunate ligaments causing scaphoid to rotate dorsally
  • AP view = Terry Thomas sign (David Letterman sign)

Written by lmwong

June 19, 2008 at 2:11 pm

Posted in bone, msk, wrist

Hook of the Hamate fracture

leave a comment »

  • Fall on outstretched hand, athletes who hold bats or rackets that lever off hook
  • Very rare, requires carpal tunnel view to see
  • Bony protruberance off the hamate on the ulnar aspect of the carpal tunnel
  • Do CT if strong clinical suspicion and plain film negative

Written by lmwong

June 19, 2008 at 2:06 pm

Posted in bone, fracture, msk, wrist

Lunate and Perilunate dislocation

leave a comment »

  • best seen on lateral wrist view
  • fall on outstretched hand

Written by lmwong

June 19, 2008 at 2:04 pm

Posted in bone, msk, wrist

Gamekeeper’s thumb

leave a comment »

  • avulsion on the ulnar aspect of the first MCP
  • torn ulnar collateral ligament
  • requires ortho consult, internal fixation

Written by lmwong

June 19, 2008 at 2:02 pm

Posted in bone, fracture, hand, msk

Mallet finger fracture

leave a comment »

  • baseball finger
  • avulsion at base of distal phalynx

Written by lmwong

June 19, 2008 at 2:00 pm

Posted in bone, fracture, hand, msk

Bennett’s Fracture

leave a comment »

  • intra-articular, dislocation fracture¬†at base of the first metacarpal/thumb, into CMC joint
  • unstable; requires internal fixation, rec ortho consult
  • fragment is being pulled by APL
  • Rolando’s fracture = comminuted Bennett’s Fracture

Written by lmwong

June 19, 2008 at 1:58 pm

Posted in bone, fracture, hand, msk

Frykman classification

leave a comment »

describing Colles’ radial and ulnar fractures
Type 1 = R, extra-articular
Type 2 = R + U, extra-articular
Type 3 = R, intra-articular radiocarpal
Type 4 = R + U, intra-articular radiocarpal
Type 5 = R, intra-articular distal radioulnar joint
Type 6 = R + U, intra-articular distal radioulnar joint
Type 7 = R, intra-articular both radiocarpal and radioulnar joints
Type 8 = = R + U, intra-articular both radiocarpal and radioulnar joints

Written by lmwong

June 19, 2008 at 1:52 pm

Medial Collateral Ligament

leave a comment »

“wavy” appearance on MR
prevents valgus angulation
2 layers separated by small bursa:

  1. tibiocollateral ligament (superficial)
  2. meniscofemoral and meniscotibial ligaments (deep)

grade 1

  • surrounding edema

grade 2

  • thickening
  • partial rupture

grade 3

  • complete rupture
  • loss of ligament continuity

Pellegrini-Stieda = post-traumatic calcification around MCL origin related to prior trauma

Written by lmwong

June 19, 2008 at 12:31 pm

Posted in bone, msk

Brodie’s Abscess

leave a comment »

  • infection becomes chronic
  • radiolucent, well-defined geographic lesion with surrounding diffuse sclerosis
  • 2/3 in metaphysis, 1/3 in diaphysis

Written by lmwong

June 19, 2008 at 2:49 am

Posted in bone, msk

AC joint separation

leave a comment »

  • complicaitons
  • hepterotopic calcifaction-ossification
  • posttraumatic osteolysis of distal clavical
  • secondary osteoarthritis
  • get weight bearing views, and comparison with other shoulder

Types
I = Sprain

  • stretching of the AC ligament
  • AC joint is stable
  • CC ligament intact
  • only seen on stress views, widening of AC joint

II = Subluxation

  • partial or complete rupture of AC ligament
  • partial disruption of CC ligament
  • widened AC (less than 5 mm or 50%), normal CC
  • arthroplasty may be needed

III

  • disruption of both AC and CC (more than 5 mm or 50%)
  • widening of AC and CC on routine film

IV = posterior

  • AC and CC ligaments disrupted
  • Coracoacromial ligament intact
  • distal end of clavical inferior and posterior to acromion (axillary views)

V = superior

  • Type IV plus sternoclavicular separation
  • marked widening of AC and CC, sternoclavicular dislocation

VI = inferior

  • distal end of clavicle displaced inferiorly and lodges in biceps and coracobrachialis muscles
  • distal end of clavicle lies inferior to acromion

link

Written by lmwong

June 19, 2008 at 1:57 am

Posted in bone, msk, trauma

Simple Bone Cyst

leave a comment »

  • unicameral bone cyst; simple bone cyst
  • fluid-filled cavity
  • fallen fragment sign: detached fragment of bone in dependent portion of cyst
  • males:females 2:1
  • calcaneus, long bones (esp children)
  • lucent, well-demarcated, geographic
  • long axis parallel to long bone
  • broader toward metaphysis than diaphysis
  • pathological fractures

Written by lmwong

June 19, 2008 at 1:47 am

Posted in bone, cystic, msk