Fig. 6

Results of immunohistochemical analysis for the two groups: MMP-13 (CON group: a–c; PI Group: A’ –C’ ); Collagen X (control group: d-f; PI Group: D’ –F’ ); TNF-ɑ (control group: g–i; PI Group: G’ –I’ ); NF-κB (control group: j-l; PI Group: J’ –L’ ). Higher expression of MMP-13 (A’ –C’ ), Collagen X (D’ –F’ ), TNF-ɑ (G’ –I’), and NF-κB( J’ –L’) were observed in the PI Group at 4, 8, and 12 weeks after surgery. The black arrows in (A’-L’) indicate positive expression and cell cluster formation. A brown color indicates positive staining. Scale bar: 50 µm (CON Group, control group; PI Group, patellar instability group)