# The Influence of Bone Bruises on Bone Tunnel Enlargement Regarding ACL Rupture
## 3 Results  
In the STGR group, a BB in the femur was not observed in six patients or in the tibia in one patient. Detailed results including the correlation coefficients between variables are presented in Table 2.  
The outcomes indicated that the time between the injury and MRI evaluation (t(I-MRI) was not related (r > 0.3) with the volume of BBs in the defined volume of the femur or tibia (_f_-BB/TVI and _t_-BB/TVI, respectively). There was also no correlation (r > 0.3) between the time from the moment of injury to ACLR (t(I-S)) and BTE, as assessed by _l_/d, _l_d, _l_/_fCSA, and _l_fCSA. A weak correlation (r = 0.33) existed between the volume of BBs (_f_-BB/TVI and _t_-BB/TVI) and the size of BTE (_l_/_f_CSA, _l_fCSA) in the femur and tibia. Considering the relationship between the distance from the BB to the bone tunnel in the femur (_f_-l) and its enlargement, there was a moderate and statistically significant (_p_ < 0.05) negative correlation (r = \(-\)0.64 for _l_/d and r = \(-\)0.59 for _l_/_f_CSA) and a weak negative correlation between the same parameters in the tibia (r = \(-\)0.40 for _l_/d and r = \(-\)0.42 for _l_/tCSA). The correlation coefficient was negative, which means that the smaller the distance between the BB and bone tunnel was, the larger the bone enlargement appeared. Five femoral and six tibial bone tunnels went directly through the BB. The correlation between  
\begin{table}
\begin{tabular}{c c c c c c c c c c c c} \hline  & **t(I-**MRI)** & **t(I-S)** & _f_-** & _t_-** & _l_/d & _l_/_f_ & _l_/_f_ & _l_/_f_ & _l_/_f_ & _l_/_f_ \\  & **MRI** & **t(I-S)** & **BB/TVI** & **BB/TVI** & & & &  
\(\cap\!f\) and \(\Delta\!f\)d was moderate (r = 0.54) and statistically significant (\(p\) < 0.05), and that between \(\cap\!f\) and \(\Delta\!f\)CSA was weak (but close to the threshold for a moderate correlation: r = 0.46). The correlation between the same parameters in the tibia was negligible. The results of the investigated correlations in subgroup B (the time interval between injury and surgery ranged from 31 to 60 days) are presented in Tables 3 and 4. We observed a significant increase in the correlation coefficients between \(f\)-BB/TVI and \(\Delta\!f\)d, and between \(f\)-BB/TVI and \(\Delta\!f\)CSA, which increased from 0.25 and 0.33 to 0.56 and 0.66, respectively (Table 3). The correlation coefficients between \(t\)-BB/TVI and \(\Delta\!t\)d, and between \(t\)-BB/TVI and \(\Delta\!t\)CSA, also increased from 0.25 and 0.33 to 0.32 and 0.36, respectively (Table 4). Regarding the relationship between \(f\)-l and \(\Delta\)fd, we observed an increase in Pearson's coefficient from \(-\)0.64 to \(-\)0.77, which can be interpreted as a strong negative correlation (Table 3). The correlation coefficient between \(t\)-l and \(\Delta\)fd, and between \(t\)-l and \(\Delta\)fdCSA, increased from \(-\)0.40 and \(-\)0.42 to \(-\)0.53 and \(-\)0.49, respectively (Table 4). The boxplots presented in Figure 5 show the tendency of bone tunnel widening at the tunnel entrance (\(f\)-d1). Based on precise engineering MRI image analysis, which was carried out twice, after injury and after surgical ACLR, the assumed negative effect of BBs on the results of ACL reconstruction regarding BTE was confirmed in the femur. \begin{table}
\begin{tabular}{c c c c c c} \hline \hline  & **Mean** & **SD** & **\(t\)-BB/TVI** & \(\Delta\)**fd** & \(\Delta\)**\(t\)CSA** \\ \hline t-BB/TVI & 11.76 & 6.18 & 1.00 & - & - \\ \(\Delta\)fd & 59.20 & 20.25 & 0.32 & 1.00 & - \\ \(\Delta\)fCSA & 176.86 & 75.93 & 0.36 & 0.96 (\(p\) = 0.00) & 1.00 \\ \hline  & & & **\(t\)-l** & \(\Delta\)**fd** & \(\Delta\)**\(t\)CSA** \\ \hline \(t\)-l & 28.83 & 8.83 & 1.00 & - & - \\ \(\Delta\)fd & 59.20 & 20.25 & \(-\)0.53 & 1.00 & - \\ \(\Delta\)fCSA & 176.86 & 75.93 & \(-\)0.49 & 0.96 & 1.00 \\ \hline \hline \end{tabular}
\end{table} 
Table 4: Results of correlation analysis for the tibia for t(I-S) = from 31 to 60 days. Correlation coefficients are statistically significant at \(p\) < 0.05 (in red).