## 3 Results
However, visually determining the variability between group 0 (Figure 4A), group 1 (Figure 4B), group 2 (Figure 4C), and group 3 (Figure 4D) is challenging. Considering the differences in the BMD between the groups related to OA severity (Figure 5), one can observe that there are no differences between the OA scores for the %color pixels quantified for S1 (Figure 5A), S2 (Figure 5B), S5 (Figure 5E), S6 (Figure 5F), S7 (Figure 5G), and S10 (Figure 5J). However, for S3 (Figure 5C) and S4 (Figure 5D), the %color pixels was lower in group 3 than in the remaining groups. Moreover, for S8 (Figure 5H) and S9 (Figure 5J), the %color pixels was higher in groups 2 and 3 than in group 1. \begin{table}
\begin{tabular}{c c c c c c c} \hline
**No** & **Sex** & **Bred** & **Lameness Score * & **Age** & **Training Background** & **OA Severity Scores** \\ \hline
7 & M & SH & Left 3; Right 3 & 21 years & Leisure work for 11 years & Left 2; Right 2 \\
8 & G & PHH & Left 3; Right 3 & 26 years & Leisure work for 19 years & Left 0; Right 3 \\
9 & G & PHH & Left 4; Right 4 & 22 years & Leisure work for 16 years & Left 3; Right 3 \\
10 & M & PHH & Left 2; Right 2 & 15 years & Leisure work for 10 years & Left 0; Right 0 \\
11 & M & MBW & Left 3; Right 3 & 25 years & Leisure work for 14 years & Left 0; Right 0 \\
12 & M & FTH & Left 2; Right 2 & 23 years & Leisure work for 16 years & Left 0; Right 3 \\
13 & M & PHH & Left 3; Right 3 & 27 years & Leisure work for 12 years & Left 0; Right 0 \\
14 & G & PHH & Left 2; Right 2 & 32 years & Leisure work for 17 years & Left 1; Right 1 \\
15 & G & PHH & Left 2; Right 2 & 26 years & Leisure work for 15 years & Left 0; Right 0 \\
16 & G & PHH & Left 4; Right 4 & 28 years & Leisure work for 15 years & Left 2; Right 2 \\
17 & G & PHH & Left 3; Right 3 & 22 years & Leisure work for 16 years & Left 1; Right 1 \\
18 & G & PHH & Left 2; Right 2 & 18 years & Leisure work for 11 years & Left 1; Right 1 \\
19 & G & PHH & Left 3; Right 3 & 27 years & Leisure work for 14 years & Left 0; Right 0 \\
20 & G & PHH & Left 2; Right 2 & 24 years & Leisure work for 15 years & Left 0; Right 0 \\ \hline \end{tabular}  
* Sec: M: mare, G: gelding; breed: PHH: Polish half-bred horse; FTH: French trotter horse; SH: Silesian horse; MBW: mixed-breed warm-blood horse.
* the lameness score was used only for pre-selection.  
\end{table} 
Table 4: _Cont._Figure 4: Exemplary dorsopalmar view radiographs of four tarsal joints decomposited to ten sub-images related to the relative density of the ten steps (S1–S10) of the density standard. (**A**) The tarsal joint in group 0 represents the normal joint, (**B**) the tarsal joint in group 1 represents mild osteoarthritis (OA), (**C**) the tarsal joint in group 2 represents moderate OA, and (**D**) the tarsal joint in group 3 represents severe OA. Figure 3: The %color pixels of (**A**) the normal tarsal joint (group 0), (**B**) mild tarsal joint osteoarthritis (OA) (group 1), (**C**) moderate tarsal joint OA (group 2), and (**D**) severe tarsal joint OA (group 3). The data for each step of the density standard (S1–S10) are presented in the bar graph mean + SD. The lowercase letters indicate the differences between the steps. The significance level was established as \(p<0.05\).