Levodopa attenuates cellular apoptosis in steroid-associated necrosis of the femoral head

Xi, Hongbo; Tao, Weijian; Jian, Zhengguang; Sun, Xuefeng; Gong, Xiaohong; Huang, Lixin; Dong, Tianhua

Histopathologic examination. Six or eight weeks later, the rabbits of the three groups were sacrificed via air embolism, then their bilateral femoral heads were harvested, split in half along the central coronal plane, placed in 10% neutral formalin solution for 24-h fixation and decalcified in 5% dilute nitric acid for one week. Following dehydration in an alcohol series the femoral heads were embedded in paraffin, cut into 4-µm-thick slices, dewaxed and hydrated prior to staining with hematoxylin for 5 min. Following staining, the slices were hydrated for 10 min, eosin-stained for 2 min, dehydrated, hyalinized and turpentine-mounted before the bone trabecular structure and changes in the bone cells and bone marrow fats were observed under a light microscope. Femoral head necrosis was determined according to the pathological features of empty bone lacuna numbers and surrounding necrotic bone marrow tissues. Any region in the slice that was found to exhibit one sign of osteonecrosis was considered to be positive for SANFH. Pathological changes in bone cellular necrosis were expressed as the percentage of empty bone lacunae. At x100 magnification in 10 randomly selected high-power fields, the number of empty bone lacunae out of 50 bone lacunae in each field were counted to calculate the percentage of empty bone lacunae.