COLLAGEN CROSS-LINKS IN CHONDROMALACIA OF THE PATELLA

The aim of the study was to determine collagen concentration and colla gen crosslinks in cartilage samples from chondromalacia of the patella . To study the extracellular matrix alterations associated to chondrom alacia, we determined the concentration of collagen (hydroxyproline) a nd its hydroxylysylpyridinoline and lysylpyridinoline crosslinks from chondromalacia foci of the patellae in 12 patients and 7 controls from apparently normal cadavers. The structure of the collagen network in 8 samples of grades II-IV chondromalacia was examined under polarized light microscopy. The full-thickness cartilage samples taken with a su rgical knife from chondromalacia lesions did not show changes in colla gen, hydroxylysylpyridinoline and lysylpyridinoline concentration as c ompared with the controls. Polarized light microscopy showed decreased birefringence in the superficial cartilage of chondromalacia lesions, indicating disorganization or disappearance of collagen fibers in thi s zone. It is concluded that the collagen network shows gradual disorg anization with the severity of chondromalacia lesion of the patella wi thout changes in the concentration or crosslinks of collagen.