Skip to main content
. 2018 Feb 27;232(6):908–918. doi: 10.1111/joa.12795

Figure 1.

Figure 1

(A, B) Selected histological healing parameters in SNU samples: cell density, gap. (A) Connective tissue with densely packed cell nuclei (purple, arrows) and collagen fibres (pink) indicating highly active tissue; HE stain. (B) Less dense filled gap with fewer cell nuclei (red, arrows) and collagen fibres (blue) representing less active tissue; AZAN stain. Scale bars: 50 μm. (C, D) Selected histological healing parameters in SNU samples: trabecular spikes/thickening. (C) Trabecula formed by secreted extracellular matrix (red) and embedded osteocytes in typical spike formation; HE stain. (D) Osteoblasts (arrows) on the trabecular surface indicate trabecular thickening; HE stain. Scale bars: 50 μm (C), 20 μm (D). (E, F) Selected histological healing parameters in SNU samples: osteoid formation. (E) Cartilage calcification in the transition zone (2, arrows). Cartilage (1) transforms gradually into bone (3) with osteoid formation (red); HE stain. (F) Same sample with collagen 2 (brown) being present in the cartilage (1) and the transition zone (2), but not in bone (3); collagen 2. Scale bars: 50 μm. (G) Selected histological healing parameters in SNU samples: cell lines (osteoblasts). Lines of osteoblasts (purple, arrow) on the trabecular surface (red); HE stain. Scale bar:  10 μm. (H, I) Selected histological healing parameters in SNU samples: blood cells/vessels. Blood cells and blood vessels supply the tissue with nutrients, oxygen and precursor cells and are a prerequisite for healing. (H) Blood vessel (dashed line) next to a trabecula (asterisk); AZAN stain. (I) Blood cells (red, arrows) next to collagen fibres (blue); AZAN stain. Scale bars:  20 μm (H), 10 μm (I). (J,K) Selected histological healing parameters in SNU samples: collagen 1 (typical for bone) and collagen 2 (typical for cartilage), gap. The presence of both collagens was observed in some cases of SNU degradation. Predominance of collagen 2 next to the gap indicates formation of late SNU. (J) Collagen 1 (brown) is found in bone (dashed line, 1) and next to the gap (3) with unspecific cartilage stain in the middle portion (2); collagen 1. (K) The same sample shows collagen 2 (brown) in the middle portion (2) and next to the gap (3); collagen 2. Scale bars:  100 μm (J, K). (L) Selected histological healing parameters in SNU samples: cartilage formation, gap. Cartilage in the gap is a sign of encapsulation and SNU. Glycosaminoglycans (purple) and cell nuclei (blue) indicate the formation of cartilage; Toluidine stain. Scale bar: 20 μm. (M, N) Selected histological healing parameters in SNU samples: osteoclasts/foam deposits. High abundance of osteoclasts as well as foam deposits are a clear negative sign of bone healing capacity. (M) Osteoclasts (red, 1) next to a trabecula (asterisk); TRAP stain and collagen 1. (N) Foam deposits (dashed line) positive for collagen 1 (brown) next to an osteoclast (red, 1) and a trabecula (asterisk); TRAP stain and collagen 1. Scale bars: 10 μm (M), 20 μm (N).