Cyst-Like Osteolytic Formations in Recombinant Human Bone Morphogenetic Protein-2 (rhBMP-2) Augmented Sheep Spinal...

Area of Science:

• Orthopedics
• Biomaterials Science
• Regenerative Medicine

Background:

• Recombinant human bone morphogenetic protein-2 (rhBMP-2) is used to promote bone healing and spinal fusion.
• Clinical reports suggest complications associated with rhBMP-2, but local adverse effects are not well-documented.

Purpose of the Study:

• To investigate the local adverse structural and biomechanical effects of rhBMP-2 in sheep undergoing anterior lumbar interbody fusion.

Main Methods:

• Anterior lumbar interbody fusion was performed in sheep with varying doses of rhBMP-2.
• Conventional and micro-computed tomography (CT) were used to assess bone fusion and structure.
• Bone mineral density, biomechanical strength, and histological changes (adiponectin, cathepsin K) were analyzed.

Main Results:

• rhBMP-2 successfully promoted lumbar spinal fusion.
• Cyst-like osteolytic formations and bone voids were observed in peri-implant areas with rhBMP-2 use.
• These voids showed decreased bone mineral density and a 32% reduction in biomechanical strength.
• Histology revealed increased fatty marrow and specific cell markers in affected areas.

Conclusions:

• While rhBMP-2 facilitates spinal fusion, it can induce detrimental local osteolytic changes in trabecular bone.
• These adverse structural alterations may compromise the bone's biomechanical integrity.
• Careful consideration of these risks is warranted for clinical rhBMP-2 applications.