Fig. 4

Fiber type grouping levels of GM, TFL, VL and RF in affected limb of HOA patients. a Representative images of fiber type grouping. Laminin staining is displayed in white, MyHC1 staining in green, MyHC2A in dark blue and MyHC2X in violet. Scale bars, 50 µm. Yellow arrowheads indicate grouped fibers. b Relative area occupied by grouped fibers. Data are presented as mean and standard deviation and were analyzed using repeated-measures one-way ANOVA and Dunnett’s post-hoc test. **** p < 0.0001 compared to the GM muscle. c Repeated-measures correlation between the relative fatty infiltrated area assessed by MRI and the fiber grouping levels. Values from each patient are displayed in one color, with corresponding lines to show the repeated-measures correlation fit for each patient. GM, gluteus minimus; HOA, hip osteoarthritis; RF, rectus femoris; TFL, tensor fascia latae; VL, vastus lateralis