Fig. 2

Representative images of cruciate ligament changes with OA development in Str/ort mice. a Toluidine blue, Collagen type II (Col2) and Sox9 immunolabelling in healthy CBA mouse cruciate ligaments, with high magnification of insertion site into the tibia. b, c Cruciate ligaments from Str/ort mouse knee joints with OA grades of 2 (mild) and 5 (severe). Toluidine blue staining showed increased staining at the insertion site (high mag for panels b and c) and within the ligament body (high mag for panel c), with hypertrophy of local cells. Col2 deposition and sox-9 positive cells were also increased, especially in severe diseased joints. Low mag = low magnification, scale bar = 100 μm; High mag = high magnification, scale bar = 50 μm. For orientation: femur at top of picture, tibia bottom