Microsphere-based gradient implants for osteochondral regeneration: a long-term study in sheep.

Abstract

The microfracture technique for cartilage repair has limited ability to regenerate hyaline cartilage. The current study made a direct comparison between microfracture and an osteochondral approach with microsphere-based gradient plugs. The PLGA-based scaffolds had opposing gradients of chondroitin sulfate and β-tricalcium phosphate. A 1-year repair study in sheep was conducted. The repair tissues in the microfracture were mostly fibrous and had scattered fissures with degenerative changes. Cartilage regenerated with the gradient plugs had equal or superior mechanical properties; had lacunated cells and stable matrix as in hyaline cartilage. This first report of gradient scaffolds in a long-term, large animal, osteochondral defect demonstrated potential for equal or better cartilage repair than microfracture.