[The status of the direct magnifying x-ray technique in orthopedics]

22 patients suffering from different orthopaedic disease patterns were x-rayed with direct x-ray magnification with focus diameters between 0.012 and 0.100 mm. This yielded improved resolution of detail structures, especially in tumours and aseptic bone necroses. Due to the relatively low efficiency of the x-ray tube (conditioned by the physics of the x-ray equipment), however, exposure times of several seconds were required, and the voltage had to be higher than in conventional x-ray procedure. This resulted in lack of sharpness due to movement and to a loss in contrast. Hence, the clinical use of focus diameters below 0.1 mm does not seem to be meaningful.