[Double-contrast arthrography in chondropathia patellae--clinical and experimental study on pathogenesis and diagnosis (author's transl)].

This study is based on the evaluation of 250 arthrographies of the patellofemoral joint ("défilé" arthrographs in Ficat's terminology) which were performed because of clinical suspicion of chondropathia patellae and which could be controlled intraoperatively in 30 cases, as well as on examinations employing an etching paste as used in metallurgy and performed on 20 knee-joints of corpses. 46% of the arthrographies showed a ridge-shaped cartilaginous thickening which was not pre-modelled in the osseous structure and which separated the medial facette into a paramedian and a marginal segment and correlated with chondromalacia to a greater degree than patellar dysplasias or secondary osseous changes. This variant, which could not be detected by plain roentgenography, must be considered as a pre-arthrotic deformity on account of the high point-shaped pressure load on the ridge. The findings were fully confirmed by macroscopic examination of the postmortem material.