## Results  
### Trabecular Thickness Varies Amongst Tested Scaffolds  
Trabecular thicknesses within the examined region of interest for all samples were calculated; these results are summarised in Table 2. It was observed that the trabecular thickness for all test groups had close values ranging from 0.26 mm to 0.33 mm. Scaffold Group 2 demonstrated the largest overall average of 0.30 mm, followed by scaffold Group 1 and 3 with 0.29 mm and Group 4 with 0.28 mm. Within Sub-set 1, TbTh measurements ranged from 0.18 mm to 0.43 mm. Measurements in Sub-set 2 ranged from 0.17 mm to 0.38 mm, while in Sub-set 3, TbTh measurements ranged from 0.15 mm to 0.47 mm (Figure 4). The average TbTh measurement across all groups was 0.29 mm.  
\begin{table}
\begin{tabular}{c|c c c c} \hline  & **Group 1** & **Group 2** & **Group 3** & **Group 4** \\ \hline Sub-Set 1 & 0.30 mm & 0.29 mm & 0.26 mm & 0.31 mm \\ Sub-Set 2 & 0.28 mm & 0.29 mm & 0.28 mm & 0.27 mm \\ Sub-Set 3 & 0.31 mm & 0.33 mm & 0.31 mm & 0.27 mm \\ Total Average & 0.29 mm & 0.30 mm & 0.29 mm & 0.28 mm \\ \hline \end{tabular}
\end{table}
Table 2: Average scaffold and sub-set measurements for trabecular thickness.  
In Group 1 and 2, the highest average TbTh was observed in Sub-set 3, suggesting that the region of the defect furthest from the joint surface experienced the greatest trabecular thickness. This was surprising because this was not visually apparent on many of the heat maps from these samples (Figure 5). This may have resulted from Sub-set 3 being furthest from the joint and thus experiencing fewer biomechanical stressors. However, Sub-set 1 within these samples did not consistently experience the least TbTh, suggesting that biomechanical stressors may not be the sole cause for the results observed within these scaffold groups.  
Similar to Group 1 and 2, Sub-set 3 also experienced the greatest TbTh average in scaffold Group 3; this was again surprising because the visual assessment of the heat maps  
Figure 4: Variation of subchondral bone trabecular thickness in tested groups and sub-sets. No statistically significant differences were observed between the measurements.  
Figure 5: Examples of trabecular thickness heat maps. Black = no tissue or scaffold. Dark colours (purple, blue) = thinner tissue. Bright colours (orange, yellow) = thicker tissue.  
did not overwhelmingly indicate this (Figure 5). Within this sample, sub-set 1 contained the lowest average measurement and Sub-set 2 the median measurement, indicating that this scaffold consistently produced greater tissue thickness in regions further from the articular surface of the joint.  
Unlike with the other groups, the average TbTh within scaffold Group 4 was largest in Sub-set 1; this was visually apparent on some, though not all, of the heat maps. This trend change within this measurement suggests that this scaffold combined with the BMC was the only sample to generate thicker bone tissue nearest to the joint after six months.  
All results for this measurement were statistically insignificant (\(p>0.05\)). This suggests that, on average, the novel scaffold and addition of BMC to scaffolds did not significantly affect bone tissue thickness after six months of scaffold implantation. Other notable trends within the data were observed, however. For example, control scaffolds with BMC exhibited a slightly higher average TbTh than control scaffolds without BMC, but novel scaffolds without BMC exhibited a slightly higher average value than those with BMC. This suggests that the addition of BMC did not consistently promote greater TbTh measurements, but the interaction of BMC with its substrate may be an important factor in bone regeneration.