*4.8. Terminal Deoxynucleotidyl Transferase dUTP Nick End Labeling (TUNEL) Assay*

TUNEL assay was performed on proximal tibia tissue sections to detect chondrocyte apoptosis (12156792910, Roche, Branchburg, NJ, USA). The percentages of TUNEL-positive cells in chondrocytes relative to 4 ,6-diamidino-2-phenylindole (DAPI)-stained cells were calculated and an analysis was conducted using a Leica immunofluorescence system (Leica MicroImaging). Photographs from three independent experiments were conducted and calculated for each experimental group.
