Osteoporosis Preclinical Research: A Systematic Review on Comparative Studies Using Ovariectomized Sheep

Area of Science:

• Orthopedics
• Metabolic Bone Diseases
• Animal Models

Background:

• Ovariectomy (OVX) in sheep is crucial for osteoporosis research.
• Variability in breed, age, and diet impacts OVX model reliability.
• Comparative studies are essential for robust osteoporosis research in sheep.

Purpose of the Study:

• To systematically review the last decade of OVX sheep studies for osteoporosis research.
• To identify key variables and methodologies in established OVX sheep models.
• To assess the characterization of bone remodeling in OVX sheep models.

Main Methods:

• Systematic review of PubMed, Scopus, and Web of Knowledge (last 10 years).
• Inclusion criteria: Studies on OVX sheep with a control group.
• Analysis of 18 selected studies.

Main Results:

• Merino sheep (5-6 years old) are predominantly used.
• Ventral midline laparotomy is the common surgical approach.
• OVX combined with steroid therapy is a widely adopted osteoporosis model.
• Significant bone mineral density and microarchitectural decline observed 12 months post-OVX.
• Bone alterations are site-specific (lumbar vertebra, femoral neck, ribs).
• Early changes (3-5 months) noted with steroid-induced osteoporosis.

Conclusions:

• OVX in sheep effectively mimics human osteoporosis, inducing systemic bone loss and structural deterioration.
• Standardized methodologies and control groups are vital for reliable osteoporosis research in OVX sheep.
• Adherence to 3Rs principles and ARRIVE guidelines ensures ethical and scientifically sound animal research.