Chondromalacia induced by patellar subluxation: Morphological and morphometrical aspects in rabbits

Abstract

The purpose of this study was to describe morphologically and quantify the changes of the articular cartilage in chondromalacia, concerning both the chondrocytes and extracellular matrix. Eight rabbits were submitted daily to patellar subluxation, causing chondromalacia after two weeks. The knee fragments obtained were processed by decalcification followed by routine histological techniques and quantitation of the chondrocyte number and sizes. These experimental conditions caused degenerative alterations of the articular cartilage, varying from a slight decrease of proteoglycans, to fibrillar changes, clefts, and horizontal splitting. The results showed a significantly increased number of chondrocytes (p < 0.000139), although smaller in size (p < 0.000109). The immobilization for 2 weeks and the intermittent passive daily motion afterwards for a period of 2 weeks, was effective to cause patellar chrondomalacia in rabbits.