Steroid-associated osteonecrosis animal model in rats

Area of Science:

• Biomedical research
• Preclinical disease modeling
• Osteonecrosis research

Background:

• Preclinical models are crucial for understanding disease mechanisms and testing interventions.
• Steroid-associated osteonecrosis (SAON) requires effective and economical animal models for study.
• Existing large animal models for SAON present challenges in cost and accessibility.

Purpose of the Study:

• To establish a unique, cost-effective preclinical rat model for steroid-associated osteonecrosis (SAON).
• To develop a detailed protocol for inducing and assessing SAON using pulsed lipopolysaccharide (LPS) and methylprednisolone (MPS) injections.
• To evaluate the efficacy of this model in simulating clinical and pathological features of SAON.

Main Methods:

• Induction of SAON in Sprague-Dawley rats via pulsed LPS and MPS injections.
• Assessment of SAON at 2 and 6 weeks post-induction using dual-energy X-ray absorptiometry (DXA), serum markers, angiography, and histopathology.
• Evaluation of bone turnover markers, tissue composition, vascularization, and hepatic changes.

Main Results:

• Successful induction of SAON with 100% incidence at 2 weeks and significant bone degradation by 6 weeks.
• Demonstrated alterations in body composition (increased fat, decreased lean mass) and reduced bone turnover markers.
• Revealed vascular changes, hepatic edema, and lipid accumulation, mimicking clinical SAON pathology.

Conclusions:

• The developed rat model effectively replicates the clinical and pathological features of SAON.
• This cost-effective small animal model provides a valuable tool for studying SAON's molecular mechanisms and testing therapeutic strategies.
• The established assessment protocols can be utilized in future SAON research.