Fig. 2

Collagen analysis of intraarticular fibrosis scar tissues treated with 0.2 mg/ml, 0.1 mg/ml HHT and saline. a As the sections were stained with Masson’s trichrome, intraarticular collagen tissues appeared blue. And the magnification was × 200. HHT suppressed epidural collagen synthesis and fibrosis in a dose-dependent manner. b Under polarized light microscopy (× 400), type I collagen was red or yellow, and type III collagen was green. With the increase of drug concentration, the content of type I collagen fibers in intra-articular fibrosis decreased significantly. c Intraarticular collagen optical density value of each group. *P < 0.05 compared with the value in control group. d HPC was expressed

as μg/mg. The amount of hydroxyproline was decreased with the rising concentration of HHT