Fig. 1.

Lacunocanalicular networks are disrupted in human OA subchondral bone. a Control cadaveric and OA specimens stained with Safranin-O/Fast Green and imaged at 0.5x (top) or 2x (bottom, scale bars: 400 μm) magnification displayed differences in articular cartilage and subchondral bone morphology on the lateral and medial sides of the tibial plateau. Subsequent analyses compared the indicated regions of interest (black boxes on top row) between control and OA specimens, and between the less affected lateral side with the more severely degraded medial side. b These identified regions of interest in Ploton silver-stained sections were evaluated at low (4x, top, scale bars: 200 μm) and high (100x, bottom, scale bars: 20 μm) magnification to visualize the lacunocanalicular network of subchondral bone. c, d Quantification of the lacunocanalicular area normalized to the bone area (c) and canalicular length (d) revealed significant OA-dependent reductions in both parameters (n = 5). Graphs show mean ± SEM. *P < 0.05 compared with respective regions of control specimens, ^⋄P < 0.05 between regions by Holm–Sidak post hoc tests