Different changes of microarchitectures of cortical and cancellous bones in sheep femoral head after long-term glucocorticoid interventions

Abstract

This study investigatedthe different effects of long-term glucocorticoid (GC) interventions on the microarchitectures of cortical and cancellous bones of the femoral head. Eighteen female skeletal mature sheep were randomly allocated into 3 groups, 6 each. Group 1 received prednisolone interventions (0.60 mg/kg/day, 5 times weekly) for 7 months. Group 2 received the same interventions as Group 1 and then further observed 3 months without interventions. Control Group was left nonintervention. After killing the animals, all femoral heads were scanned by micro-CT to determine their microstructural properties. In cancellous bone of femoral head, GC interventions led to significant decrease of bone volume fraction, trabecular thickness, trabecular separation, but increase of structure model index and bone surface density (p < 0.05). While in cortical bone, there were no differences between the Group 1 and in microstructural properties (p > 0.05) except greater trabecular thickness in the control group. In addition, three months after cessation of glucocorticoid interventions, most microstructural properties of cancellous bone were significant reversed, but not cortical thickness of femoral head. In contrast to cancellous bone, the microarchitectures of cortical bone were not changed obviously after long-term GC interventions.

Figure 1

Microarchitectural properties of cancellous bone in femoral head. (A–C) BV/TV, TB.TH and TB.SP of cancellous bone in different groups. *P < 0.05, **P < 0.01. BV/TV, bone volume fraction; TB.TH, trabecular thickness; TB.SP, trabecular separation.

Figure 2

Microarchitectural properties of cortical bone in femoral head. (A–C) pore size, CortTH and porosity of cortical bone in different groups. *P < 0.05, **P < 0.01. CortTH, Cortical thickness.