A skyline-view imaging technique for axial projection of the patella: a clinical study.

Our purpose in this study was to evaluate the clinical usefulness of a new skyline-view imaging technique for axial projection of the patella with use of the anterior border of the patella and tibial tuberosity as position indicators. Our database consisted of pairs of axial images of the patella of the same patients, obtained with use of conventional and new techniques for the radiographic diagnosis of knee-joint diseases. A total of 118 pairs of knee images were obtained from 103 patients ranging in age from 16 to 86 years (mean age 49.7 years). The patellar axial positioning errors were determined in each of the images obtained with the two techniques. The relative error according to the patellar tilt was determined from each of the axial images of the patellas of the same patients obtained with the conventional and new techniques for the radiographic diagnosis of knee-joint diseases. The patellar axial positioning error was 0.40 with the conventional technique, whereas that with the new technique was significantly different at 0.30. This clinical study confirmed that the new skyline-view imaging technique, which uses the anterior border of the patella and the tibial tuberosity as position markers that can be confirmed by palpation, provides more accurate axial images than the conventional imaging technique.