Background: The microfracture technique for cartilage repair has limited ability to regenerate hyaline cartilage.
Aim: The current study made a direct comparison between microfracture and an osteochondral approach with microsphere-based gradient plugs.
Materials & methods: The PLGA-based scaffolds had opposing gradients of chondroitin sulfate and β-tricalcium phosphate. A 1-year repair study in sheep was conducted.
Results: 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.
Conclusion: This first report of gradient scaffolds in a long-term, large animal, osteochondral defect demonstrated potential for equal or better cartilage repair than microfracture.
Keywords: cartilage regeneration; chondroitin sulfate; gradients of signals; microfracture; microsphere-based scaffold; osteochondral tissue engineering.