Radiology - Conditions (Subscribe)  

arachnodactyly
* Marfan syndrome
* homocystinuria

Arthritis may, at times, present a mystifying appearance to the radiologist. However, even complex cases will usually yield to a logical and systematic approach. My personal approach involves consideration of each of the following five principles in turn:
1. Sutton's law
2. Radiographic hallmarks
...

arthritic
congenital
infectious
traumatic

# incidence: 4% of cervical spine injuries
# site: * posterior arch * anterior arch * massa lateralis * Jefferson fracture

In the appendicular skeleton, one is mostly concerned with the diarthrodial synovial joints. While this type of joint is also found in the axial skeleton (the facet (a.k.a. aphophyseal) joints and portions of the sacroiliac joints), there are also many amphiarthrodial joints which are not synovial (the intervertebral disc joints)....

* incidence: 6% of cervical spine injuries
* associated with atlas fractures in 8%
* hyperflexion injury: odontoid fracture
* hyperextension injury: hangman's fracture

intra-articular fracture of distal radius
* dorsal displacement of separated fragment
* due to fall on outstretched hand

# small, intramedullary island of compact bone
# usually (-) on bone scan
# shaggy, slightly stellate border

Sensitivity . . 98%
* False negatives:
o multiple myeloma
o thyroid Ca
o small, purely lytic lesions
...

* rhabdomyosarcoma
* neuroblastoma
* histiocytosis X
would add Ewing's (OWL editor)

Subacute osteomyelitis
* distal end of long bones
* well-defined, lytic
* +/- sclerotic rim
* tx: open abscess, curette, pack with bone chips
* prognosis: excellent after tx

There is an expanding lesion of the upper metaphysis of the right humerus. It thins the cortex from below and appears multiloculate. There is a thin zone of transition between the lesion and normal bone.

manifestations can occur singly or in any combination
* pseudogout
* arthropathy
* chondrocalcinosis

Clinical presentation: A 60 year old man with increasing weakness in the legs.
The contrast views are oblique views of the cervical spine. The contrast is asymmetrical in the left hand image. The cord is displaced by a lesion, which is compressing the contrast in the sub-arachnoid space. The appearance is of...

* posterior elements
o JRA
* vertebral bodies
o block vertebrae
o Klippel-Feil