Abaloparatide Enhances Fusion and Bone Formation in a Rabbit Spinal Arthrodesis Model.

Area of Science:

• Orthopedics and Spine Surgery
• Pharmacology and Drug Development
• Biomedical Engineering

Background:

• Pseudarthrosis remains a significant complication following spine fusion surgery.
• Abaloparatide, a parathyroid hormone-related peptide analog, has shown promise in preclinical models for enhancing bone fusion.
• The efficacy of abaloparatide in larger animal models for spinal fusion was previously unknown.

Purpose of the Study:

• To evaluate the effect of daily subcutaneous abaloparatide injections on intervertebral fusion rates.
• To assess abaloparatide's impact in a rabbit posterolateral spinal fusion model.

Main Methods:

• A prospective, randomized, placebo-controlled animal trial was conducted.
• 24 rabbits underwent posterolateral spine fusion and were randomized to receive either abaloparatide or saline.
• Fusion was assessed manually, radiographically (X-ray, high-resolution peripheral quantitative CT), and biomechanically.

Main Results:

• Abaloparatide treatment resulted in a 100% fusion rate compared to 45% in controls (P <0.02).
• Radiographic analysis showed significantly higher fusion scores and bone volume in the abaloparatide group (P <0.001).
• Abaloparatide increased bone formation metrics but did not affect biomechanical stability in this model.

Conclusions:

• Abaloparatide significantly improves intervertebral fusion rates in a rabbit posterolateral fusion model.
• The drug demonstrated marked increases in radiographic fusion assessment.
• Abaloparatide represents a potential therapeutic agent for enhancing spinal fusion outcomes.