[Radiography scale in rheumatology. State of the art and consequences for clinical practice]

Realize a "state of the art" of numerization and reduction or magnification scale of musculoskeletal radiography. Looking for the factors associated with this scale variation. How do they influence rheumatology practice.

The study recenced all the numerized (RN) and conventional radiography (RC) of one hundred consecutive patients consulting a rheumatologist practitioner. The scale was read directly or on gradations on the side of the radio. All the measure was made with a graduated magnifying glass.

This study confirms that RN gradually replace RC in musculoskeletal radiology (0% before 1994, 65% in 1999). It also confirms that reducing scale is more frequent (50% in 1994, 82% in 1999). The scale of reduction is significantly different depending on some anatomic area, some diagnosis and some geographical provinces. These scale modifications disturb some recommended measures in rheumatology practice. The significant correlation between reducing scale and joint space (r=-0,32; p=0, 009; n=67) tend to show that scale reduction provide an overestimation of joint space.

Given the perturbation induced in rheumatology practice it would be better to keep the scale of 100% until relevance of reducing scale has been demonstrated.