Histological findings at 1 week after tendon-to-bone repair. (A) Repair only. (B) Repair + CS. (C) Repair + P407 (hematoxylin and eosin; magnification, ×100, insets × 400). The inflammatory reaction was more marked in the repair + CS specimens. Arrows indicate angiogenesis, and dashed arrow indicates inflammatory cells. Scale bars, 100 μm. (D) Repair only. (E) Repair + CS. (F) Repair + P407 (immunohistochemical staining with rabbit monoclonal anti-CD34, ×200). Vascular endothelium was stained with a brown color. Capillary proliferation was observed less in the repair + CS specimens than in the repair only and repair + P407 specimens. Scale bars, 200 μm.