Strategic School Improvement Fund: updated 12 September 2017

<p><b>Comparison of MRI (A and B) with histological findings (C).</b> The lateral tibia plateau region of the sham knee joint of animal #8958 showed no salience neither in the sagittal MRI-scan (A) through the lateral compartment of the knee nor in the coronal MRI-scan (B) and was therefore rated as unchanged. The scale bars for A and B were determined with the program RadiAnt DICOM viewer (see caption <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0165897#pone.0165897.g001" target="_blank">Fig 1</a>). In contrast to the MRI results, the histological safranin-o staining (C) showed a moderate degeneration (Little-score: 10.5 points) with a fissure (1) in the cartilage and detachment of the topmost layer of the cartilage tissue. The histological finding and the MRI result did not concur.</p

Primer sequence, annealing temperatures (AT) and PCR product size for the different genes.

<p>Primer sequence, annealing temperatures (AT) and PCR product size for the different genes.</p

MRI of the knee joint in the control group and after ACLR.

<p>In the sagittal cross section of a control knee (A), the medial meniscus is homogenously black. The femur and tibia are on top of one another. In the knee joint after ACLR, the lack of the ACL caused the tibia to be moved forwards (B1). However, the menisci are still homogeneously black (B2). There is no evidence of degeneration in AH, PI and PH of the medial menisci (C). There is also no evidence of degeneration in the lateral menisci (D).</p

Qualitative immunohistochemical analysis of type I collagen in the PI.

<p>No staining without antibody (A), weak staining in the control group and more intense staining after ACLR (C).</p

MRI-based classification of meniscal degeneration (adapted from [30]).

<p>MRI-based classification of meniscal degeneration (adapted from [<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0159331#pone.0159331.ref030" target="_blank">30</a>]).</p

HE-staining-based four-stage scoring system for meniscal degeneration [32].

<p>HE-staining-based four-stage scoring system for meniscal degeneration [<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0159331#pone.0159331.ref032" target="_blank">32</a>].</p

Results of the qRT-PCR. The normalized expression of medial menisci in the control and ACLR group is compared and the changes in expression are described.

<p>Results of the qRT-PCR. The normalized expression of medial menisci in the control and ACLR group is compared and the changes in expression are described.</p

Histological evaluation of the degeneration in the PI of menisci in the control (A, B) and ACLR (C, D) group.

<p>A four step scoring was performed using hematoxylin-eosin staining. In case of homogeneously stained matrix with balanced cell distribution (A) degeneration was graded O. If additional matrix clefts occurred, degeneration was graded 1 (B). Degenerative changes such as moderate basophilic (blue) matrix staining in accordance with matrix clefts have been graded 2 (C). Additional mucoid changes (circle in D) and the separation of the fibrocartilage represent third grade degeneration (D). The grade of degeneration in AH, PH and PI of all medial menisci has been determined (E). Clear degeneration was only able to be observed in the medial menisci after ACLR (F).</p

Gene Expression.

<p>Normalized (ß-actin) gene expression for the evaluated genes from the examined regions of ACLR and sham knee joints. The results showed no evident differences between the ACLR and the sham operated side for the assessed genes A) <i>col1A1</i>, D) <i>mmp1</i>, E) <i>mmp3</i>, F) <i>mmp13</i>, H) <i>adamts5</i>, I) <i>il-1ß</i> and J) <i>vegf</i>. This would concur with the histological findings, where the sham operated group was as degenerated as the ACLR group and therefore not usable as a serious control group. The gene expressions of B) <i>col2</i>, C) <i>acan</i> and G) <i>adamts4</i> at first sight appeared to be differently expressed but as standard deviation was high, significant differences were not found. So no significant differences between the ACLR and sham sites were found in terms of gene expression in the end and therefore, no discrimination between an induced (ACLR) and spontaneous (sham) OA could be made.</p

Macroscopic overview.

<p>A) The femoral condyles of the ACLR knee joint of animal #8952 showed no visible change/deterioration of the cartilage. B) The femoral condyles of the ACLR knee joint of animal #8955 showed different characteristics in form of a reduced cartilage coating (1) in the lateral condyle and even erosion of the cartilage (2) in the medial condyle. C) The lateral tibia plateau surface of the sham-operated knee joint of animal #8958 showed a slightly rough cartilage surface (arrow). A-C: The scale bars were determined with the corresponding x-ray images using the program RadiAnt DICOM viewer (build 3.4.1.13367, retrieved from <a href="http://www.radiantviewer.com/" target="_blank">http://www.radiantviewer.com</a>; October 12th 2016; Medixant (Poznan, Poland)).</p