MORPHOMETRIC STUDY OF THE FEMOROPATELLAR JOINT ON LATERAL X-RAYS

Purpose of the study The goal of this study was to specify criteria of femoro-patellar joint normality on lateral view. Material This study was based on radiological examination of 102 knees in 51 adults (avera ge age 26.1 years). It concerned 29 women and 22 men that had never su ffered from their knee and were supposed healthy. Methods The radiolog ical protocol was the following : a lateral view at 45 degrees of flex ion, two lateral views in extension, with and without quadriceps contr action. The analysis was focused on patellar surface aspect, its heigh t, its depth and covering measurement. Results We found 83.7 per cent of so-called ''normal'' patellar surface, and 12.7 per cent of ''abnor mal'' patellar surface (dysplasia) in the absence of pain. Discussion We have confirmed figures advanced in others series of the literature concerning patellar height and patellar surface, as well as patellar s urface depth and covering. We have underlined the interest of lateral views; in extension with quadriceps contracted and relaxed. Finally, w e have defined a trochleo-patellar sign that allows to correlate patel lar height to patellar surface height (ITP = 0.35 to 0.84). Conclusion This study insists on the interest of radiological lateral views of t he knee and determin criteria for normalities.