Figure 3. Morphology and proliferation rate of chondrocytes from OA and fractured patients in vitro. (A) Phase contrast micrographs of human chondrocytes in culture from articular cartilage of fractured and OA patients (F-HACs and OA-HACs). (B) Growth curve of F-HACs and OA-HACs in culture. (C) Representative images of Ki67 and p21 immunocytochemistry on F-HACs and OA-HACs. Bar graphs show the percentage of Ki67+ and p21+ cells. Data are expressed as mean values ± SEM of three independent experiments. Abbreviation: F-HACs, fractured patient human articular chondrocytes; OA-HACs, OA-Human articular chondrocytes. Student’s t-test: *P < 0.05, **P < 0.001, ***P < 0.0001.