Assessment of lumbosacral fusion mass by angled radiography - Technical notes

Study Design. Lumbosacral fusion masses were assessed by angled radiography. Objectives. To introduce the use of the angled anteroposterior radiograph in the evaluation of the fusion mass at the lumbosacral region. Summary of Background Data. Determination of the presence and progress of the fusion mass at the lumbosacral junction may be difficult clinically and radiologically. Few studies regarding the use of the angled anteroposterior view of plain radiographs in evaluating L5-S1 fusion are available. Methods. The patient was placed in the supine position, and an angled view of the lumbosacral junction was obtained. Radiography of the angled anteroposterior view was performed with the x-ray beam oriented toward the cranial portion at 50 degrees to 55 degrees relative to the x-ray table. Results. The use of the angled view of the lumbosacral junction eliminates the superimposition of the L5 transverse process on the posterior part of the superior ala of the sacrum, widens the L5-S1 intertransverse space, and enhances direct visualization. Conclusions. The use of the angled anteroposterior view on plain radiographs is recommended in the evaluation of the fusion status at L5-S1.