Radiographs (A, B), histology (C, D, mineralized tissue identified with arrows), and micro-CT (E) of A6 scaffolds 3 weeks after intramuscular implantation alone (A, C) or when loaded with BMP-2 (B, D, E). Ectopic mineralized tissue formation was only evident in samples that contained BMP-2 and the tissue formed a porous structure that templated the implanted scaffolds.