Distribution pattern of OA scores, senescence levels, and telomere lengths around the central eroded area of the medial and lateral plateau. OA grade (A), senescence level (B), and telomere length (C, D) were determined in biopsies taken close to and away from the central eroded area (yellow) in four orthogonal directions (as shown in Figure 1): towards the back and the front (pink bars) and towards the lateral and the medial sides (blue bars). Telomere length was assessed through Universal STELA (C) and Q-FISH (D). OA grades are expressed as Mankin scores, SAHF evaluation of senescence is shown in percentage of cells positive for SAHF per total cell number, Universal STELA data are presented as the number of telomeres below a length of 1,500 bp per genome equivalent of template DNA, and Q-FISH data are shown in arbitrary units reflecting the relative mean telomere length. Missing measurements are due to biopsies inappropriate for analysis due to too low levels of DNA or too damaged tissue. bp, base pair; OA, osteoarthritis; Q-FISH, quantitative fluorescence in situ hybridization; SAHF, senescence-associated heterochromatin foci; STELA, single telomere length assay.