X-ray analysis: visual indicators

Motion unit

two adjacent vertebrae, facet joints, disc, and all adjoining ligaments

Visual posteriority

1.) interruption in George’s line when comparing the posterior aspect of the vertebral body to the vertebral body below the segment below

2.) posteriority is when the superior segment is posterior to the segment below exhibited at one motion unit → acute condition

Stair stepping

1.) 3 or more adjacent vertebral bodies that exhibit visible posteriority

2.) list the lowest segment exhibiting visible posteriority, usually indicates chronic conditions

Stacking

1.) posterior aspect of the vertebral bodies of 3 or more consecutive segments are in a straight line → due to loss of normal curve

2.) most inferior segment in the stack will be listed posterior

Hour-glassing

1.) could be due to lateral tipping of the vertebra or may be caused by patient positioning and the diverging central rays

2.) it appears as an ellipse at the superior and/or inferior aspects of the endplates

Thin disc

1.) indicator of an involved motion unit, if one disc is seen to be thinner than disc above and below

2.) indicates chronic condition

Schmorl’s Node

1.) associated with fractures of the vertebral endplates

2.) nodes are seen as invagination of nuclear material into the body of the vertebra

3.) usually well-defined areas of radiolucency and indicate a chronic condition. vertebral segment that is on top of involved disc is listed

Eburnation

1.) conversion of a bone into an ivory like mass

2.) in osteoarthritis the thinning of the articular cartilage is due to disorganization and fragmentation of the superficial tissue and extension of degenerative change to the deeper part of the cartilage

3.) change results in exposure of the subchondral bone, which becomes denser while the surface area becomes worn

4.) increased density and will indicate chronic condition

Osteophytes

Spurring (exostosis / osteophytic changes)

IVF encroachment

1.) lateral projection of the spine due to the fact that the vertebral foramina are easily seen on this view

2.) comparison of the vertebral foramen to those above and below and observation for consistency in size is performed

3.) foramina that appear to be relatively narrower and may be an indicator of posteriority

4.) IVF may be acute or chronic condition

Reversed or increased disc wedge

if it is to the anterior aspect of the disc it is associated with chronic condition

Reverse wedge indicates acute condition