A clear understanding of the pathophysiology of anterior knee pain is inhibited by the use of imprecise, poorly defined, and often interchanged words, such as malalignment, patellar alignment, maltracking, subluxation, dislocation, and congruence. The literature is filled with articles regarding the diagnosis, "malalignment of the patella," most of which give no precise diagnosis. This article presents a definition of malalignment and a plea for rational descriptive and scientific analysis. Much of what is described is based on theory, not facts. These ideas are supported by clinical experience and logical analysis, but very little in the way of scientific data. Most of the data involve radiographic images, which present only one piece of the puzzle.