Effect of ofloxacin on the cartilage of the knee joint of juvenile rats

Ofloxacin is one of fluoroquinolones derivatives, which has a broad spectrum bacterial activity. It is contraindicated in children and adolescents because of its potential chondotoxicity in juveniles. However, fluoroquinolones continue to be prescribed as a drug of choice for treatment of some life threatening diseases in pediatrics. This study was conducted to examine the effect of ofloxacin on cartilage of juvenile rats by light and electron microscopes. Twenty newborn albino rats were treated with an oral dose of 900 mg/kg/day of ofloxacin for 28 days. The animals were sacrificed after the completion of the administration and the knee joints were prepared for light and electron microscopic examination. Morphometric study and statistical analysis of the results were also performed. The lesions were demonstrated in the articular cartilage of all the animals. Fissures, chondrtocyte clusters and wide area of matrix devoid of cells in the intermediate zone were observed. The surface of the premature articular cartilage of the femur was irregular. The matrix of the articular cartilage showed less staining with toluidine blue and masson trichrome. Electron microscopic results showed separation between chondrocyte cell membrane and the matrix. The chondrocytes were necrotic with pyknotic nuclei and vacuolation of their cytoplasm. There were electron dense aggregates on the cell membrane and inside the cells. The thickness of the premature articular cartilage and epiphyseal plate cartilage were significantly decreased. The numbers of chondrocytes of the premature articular cartilage and epiphyseal plate cartilage were significantly decreased. The numbers of chondrocytes of the premature articular cartilage and epiphyseal plate cartilage were significantly decreased