Figure 1

Animals that were used for micro–computed tomography were also used for histological analysis. (A) Hematoxylin and eosin (H&E)–stained sections of control and surgically treated knees from wild-type (WT) and inactivated mitogen-inducible gene 6 (Mig-6^−/−) mice at 2 weeks after surgery (original magnification, 4×). Boxed regions are shown at higher magnification (original magnification, 20×). (B) Pentachrome-stained sagittal sections of control and surgically treated knees from WT and Mig-6^−/−mice at the 2-week time point. The black arrows point to joint space narrowing, the yellow arrows point to cartilage degradation and fibrous tissue is outlined in blue. Muscle is stained red, cartilage blue, fibrin bright red, and reticular yellow. Fibrous tissue area was quantified using ImageJ software (data are mean ± SE). (C) H&E-stained sections of control and surgically treated knees from WT and Mig-6^−/−mice at 4 weeks (original magnification, 4×). Boxed regions are shown at higher magnification (original magnification, 20×). (D) Pentachrome-stained sagittal sections of control and surgically treated knees from WT and Mig-6^−/−mice at the 4-week time point. The black arrow points to joint space narrowing. Yellow arrows point to cartilage degradation. Fibrous tissue within the joint space of Mig-6^−/−surgically treated knees is shown at 20× and 40× original magnification and was quantified using ImageJ software (mean ± SE).