Figure 2. The bone-strengthening pill (BSP) reduces osteonecrotic changes in osteonecrosis of the femoral head (ONFH) in rats.

Histological observations of the femoral head are shown. (A) The surface of the femoral head is smooth and the cartilage cells show columnar growth pattern. (B) The surface of the femoral head is necrotic and shredded. Collapse and defectsare observed. (C) The surface of the femoral head is smooth and the cartilage cells show columnar growth pattern. (D) Curvature, disturbance, and rupture of bone trabecula are observed. (E) There is abundant distribution of bone trabecula, which has a normal structure. (F) Focal necrosis of marrow cells. (G) No necrosis of marrow cells is observed. (H) A few fat particles adhering to the surface of the cartilage cells were observed. (I) A large amount of fat particles are observed inside the cartilage cells. (J) A few fat particles adhering to the surface of the cartilage cells were observed. (K) Abundant capillaries with clear marginsare observed to form a capillary network and arcuate cup. (L) The capillaries were sparse inside the femoral head and the arcuate cupdisappeared. (M) There was a significant increase in capillaries inside the femoral head with clear margins, with recovery of the arcuate cup.