Fig 4. Control 40% (A, C) and 50% (B, D) defects three months post-operation.

(A, B), whole mounts stained with methylene blue/alizarin red. C, D, H & E-stained sections. No regeneration has taken place. In the sections, muscle and connective tissue have filled the defect space (arrows). T = tibia. Bars = 400 μm.