Immunofluorescence staining against α-SMA was performed to detect vascular smooth muscle cells (26 (link)) and myofibroblasts (27 (link)), according to the manufacturer’s protocol. Briefly, after dewaxing, rehydration, and antigen retrieval, the sections were blocked with 2% bovine serum albumin in phosphate buffer saline (PBS) for 1 h. Sections were incubated with anti-α-SMA antibody (Arigo Biolaboratories, Taiwan, China) overnight at 4 °C and then with goat anti-mouse secondary antibody labeled with Alexa 488 (Molecular Probes, Invitrogen, Carlsbad, CA) for 1 h at 37 °C. At the end of the incubation period, the sections were washed with PBS and counterstained with DAPI (Life Technologies, CA, USA). Images were observed using fluorescence microscopy (IX53, Olympus) for further semiquantitative analysis. For each section of the intraosseous or intra-articular part, six random fields of view (FOV) around the graft were randomly selected, and α-SMA positive vessels and myofibroblasts were counted by two independent observers using Image-Pro Plus 6.0. (27 (link),28 (link)). The positive ellipse was an α-SMA-positive vessel, and the positive spindle cell was an α-SMA-positive myofibroblast.