Figure 2 A–E.

No difference of muscle fibrosis between MMP-13 knockout (KO) and wildtype (WT) mice. Sections of supraspinatus muscle from all mice groups (n=4) were analyzed for collagenous connective tissue using Masson Trichrome staining and photographed at 20×. Groups were separated into: A) wild-type sham side, B) wild-type surgery side, C) knockout sham side, and D) knockout surgery side, showing increased accumulation of collagen deposition in supraspinatus muscle at surgery side in both MMP-13 knockout and wildtype mice. However, no difference was seen in between MMP-13 knockout and wildtype mice (E) (p=0.61).