Radiographs and histological aspect of hind limbs at Day 21 after the onset of arthritis. Experiments were performed in controls rats (A, D), AIA rats (B, E) and nor-NOHA treated rats (C, F). On radiographs, both AIA and treated AIA rats exhibited a thickening of the soft tissues of the ankle and foot as well as a joint destruction and periosteal tissue neoformation. Histological slices were stained with HES (enlargement × 20). A severe joint destruction associated to synovial proliferation was present in AIA and treated AIA rats.