H&E staining of samples from each experimental group.

Normal control group (A): Intact, dense, full trabecular bone, clearly visible bone cells in the trabecular bone (arrow), isolated and scattered empty lacunae, abundant bone marrow hematopoietic cells, relatively few fat cells and normal morphology. Model control group (D): Fractured trabecular bone with fragments, an absence of bone cells from some bone lacunae (→), an increased number of empty lacunae, disorganized or absent bone marrow structure and necrosis of a large number of bone marrow cells. Core decompression group, week 4 (B): New capillaries and a small number of ossification centers around a tunnel (→), swelling of the bone marrow compared with the normal control group, an increased number of fat cells, thinning and fractured trabecular bone, a slight increase in the number of empty lacunae and nuclear condensation of a small number of cells. Core decompression group, week 8 (C): An increased number of bone cells in the trabecular bone, an increased number of bone marrow hematopoietic cells (→) and a decreased number of empty lacunae. Negative pressure group, week 4 (E): Disarranged new trabecular bone and a large number of surrounding osteoblasts (→); trabecular bone fracture and necrotic bone marrow cells remain. Negative pressure group, week 8 (F): Intact trabecular bone, clearly visible bone cells in the trabecular bone (→), abundant bone marrow hematopoietic cells, relatively few fat cells and normal morphology resembling normal bone tissue.