## 3 Results
### Association of Pain Score Changes with OA Grade  
The association of pain score changes with OA grade in different treatment groups was analysed. Table 6 shows the correlation between the OA grade and the changes in the VAS and WOMAC scores at 3 and 12 months in response to treatment. Negative r values mean that better improvement is achieved in patients with a higher OA grade, and positive \begin{table}
\begin{tabular}{c c c c c} \hline \hline  & **Pretreatment** & **3-Month Follow-Up** & **1-Year Follow-Up** &
\begin{tabular}{c} **Significance of Change in VAS** \\ **Score after Treatment** \\ \end{tabular} \\ \hline
**Treatment** & **Mean \(\pm\) SD** & **Mean \(\pm\) SD** & **Mean \(\pm\) SD** & **Mean \(\pm\) SD** \\
**Group** & **(N)** & **(N)** & **(N)** & **\(p\) Value** \\ \hline HA & 4.3 \(\pm\) 1.2 (171) & 2.2 \(\pm\) 1.4 (145) & 2.9 \(\pm\) 3.0 (30) & \(\dagger\)\(p\)\(<\) 0.001, \(\dd\)\(p\) = 0.017, \(p\) = 0.164 \\ ACS & 4.5 \(\pm\) 1.3 (222) & 1.9 \(\pm\) 1.0 (201) & 2.7 \(\pm\) 2.8 (50) & \(\dagger\)\(p\)\(<\) 0.001, \(\dd\)\(p\) = 0.001, \(p\) \(<\) 0.001 \\ BMAC & 4.7 \(\pm\) 1.5 (112) & 1.8 \(\pm\) 0.8 (98) & 3.0 \(\pm\) 0.8 (25) & \(\dagger\)\(p\)\(<\) 0.001, \(\dd\)\(p\) = 0.003, \(p\) = 0.003 \\ Total & 4.5 \(\pm\) 1.3 (505) & 1.6 \(\pm\) 1.15 (444) & 2.9 \(\pm\) 2.7 (105) & \(\dagger\)\(p\)\(<\) 0.001, \(\dd\)\(p\) = 0.001, \(p\) \(<\) 0.001 \\ \hline \hline \end{tabular} VAS = Visual Analogue Scale; HA = hyaluronic acid; ACS = autologous conditioned serum; BMAC = bone marrow aspirate concentrate; statistically significant improvement between \(\dagger\) 0 and 3 months, \(\dd\) 0–12 months, 3–12 months.  
\end{table} 
Table 4: Change in VAS score 3 and 12 months after the treatment with HA, ACS and BMAC. Figure 2: Forest plot showing VAS and WOMAC scores in patients treated with three different treatment modalities. Mean score values \(\pm\) SEM are presented. Sample sizes of individual groups are presented in Figure 1. OA = osteoarthritis; VAS = Visual Analogue Scale; WOMAC = Western Ontario and McMaster Universities Osteoarthritis Index. HA = hyaluronic acid; ACS = autologous conditioned serum; BMAC = bone marrow aspirate concentrate. values mean that a better improvement is achieved in patients with lower OA grades. In general, better short-term (at 3 months) results are observed in patients with higher grades of OA, and better long-term results are observed in patients with lower grades of OA. The patients from the three treatment groups with OA grade I and II had improvement in pain and function at both 3 and 12 months after treatment; the short-term improvement achieved in patients with grade III changes was decreased at 12 months (Figure 3); negative values of the presented score changes mean decrease of pain. Figure 4 shows the changes in VAS and WOMAC scores according to the grade of OA in different treatment groups to illustrate associations given in Table 6. The improvement in pain scores at 3 months decreased significantly at 12 months in all three treatment groups. In the HA group, an increase in the VAS and WOMAC scores at 12 months was observed in patients with grade III OA. In patients with grade III OA treated with ACS, pain scores were not significantly different from baseline values. In the BMAC group, a significant decrease in pain scores was sustained at the 12-month follow-up, even in cases with OA grade III (Figure 4).