Fig. 3

Fiber type composition of GM, TFL, VL and RF in affected limb of HOA patients. a Representative images of fiber type immunofluorescence. Laminin staining is displayed in white, MyHC1 staining in green (type 1), MyHC2A (type 2a) in dark blue and MyHC2X (type 2b) in violet. Scale bars, 50 µm. b Relative fiber type content assessed in the muscle biopsies. c Fiber size according to type. d–f Repeated-measures correlations between Type 1 fiber content and relative fatty infiltrated area assessed by magnetic resonance imaging (MRI) (d) or adipocyte area in the biopsies (e), and between type 2X fiber content and relative fatty infiltrated area assessed by MRI (f). Values from each patient are displayed in one color, with corresponding lines to show the repeated-measures correlation fit for each patient. b, c Data presented as mean and standard deviation. Data were analyzed using repeated-measures one-way ANOVA and Dunnett’s post-hoc test (b, type 1 fibers), Friedman tests and Dunn’s post-hoc (b, type 2A and 2X fibers), mixed model followed by Dunnett’s post-hoc to assess differences between the GM and other muscles, or by Tukey’s post-hoc to assess differences between fiber types (c) or repeated-measures correlation (d-f). * p < 0.05, ** p < 0.005, *** p < 0.0005, **** p < 0.0001 compared to the GM. GM, gluteus minimus; HOA, hip osteoarthritis; RF, rectus femoris; TFL, tensor fascia latae; VL, vastus lateralis