The Role of 99mTc-Annexin V Apoptosis Scintigraphy in Visualizing Early Stage Glucocorticoid-Induced Femoral Head Osteonecrosis in the Rabbit

Abstract EN

Objective.

To validate the ability of 99mTc-Annexin V to visualize early stage of glucocorticoid-induced femoral head necrosis by comparing with 99mTc-MDP bone scanning.

Methods.

Femoral head necrosis was induced in adult New Zealand white rabbits by intramuscular injection of methylprednisolone.

99mTc-Annexin scintigraphy and 99mTc-MDP scans were performed before and 5, 6, and 8 weeks after methylprednisolone administration.

Rabbits were sacrificed at various time points and conducted for TUNEL and H&E staining.

Results.

All methylprednisolone treated animals developed femoral head necrosis; at 8 weeks postinjection, destruction of bone structure was evident in H&E staining, and apoptosis was confirmed by the TUNEL assay.

This was matched by 99mTc-Annexin V images, which showed a significant increase in signal over baseline.

Serial 99mTc-Annexin V scans revealed that increased 99mTc-Annexin V uptake could be observed in 5 weeks.

In contrast, there was no effect on 99mTc-MDP signal until 8 weeks.

The TUNEL assay revealed that bone cell apoptosis occurred at 5 weeks.

Conclusion.

99mTc-Annexin V is superior to 99mTc-MDP for the early detection of glucocorticoid-induced femoral head necrosis in the rabbit and may be a better strategy for the early detection of glucocorticoid-induced femoral head necrosis in patients.