## 3 Results  
There was no significant difference in the location, distribution, or volume of osteoblasts according to sex, age, or BMI (\(p\) = 0.14, \(p\) = 0.60 and \(p\) = 0.97, respectively). The osteolysis volume was significantly larger in the talus than in the tibia (162.1 \(\pm\) 13.6 and 54.9 \(\pm\) 6.1 mm\({}^{3}\), respectively, \(p\) = 0.00). The average osteolysis volumes in the tibia and talus are shown in Figures 4 and 5, respectively. The osteolysis volumes in the closest peripheral and mid-peripheral tibial regions were 3.6-5.4-fold larger than in the distant peripheral region of the distal tibia (\(p\) = 0.00). The average osteolysis volume in the distant peripheral region was 2.4 \(\pm\) 0.8% and did not differ significantly among the VOIs (D_VOIs 1-9) (\(p\) = 0.90). The average osteolysis volume in the mid-peripheral region was 8.5 \(\pm\) 1.6% and also did not differ significant among the VOIs (M_VOIs 1-9) (\(p\) = 0.52). However, significant differences were apparent among the osteolysis volumes of the VOIs in the closest peripheral region (C_VOIs 1-9) (\(p\) = 0.00). The average osteolysis volume was 12.9 \(\pm\) 1.9%. All closest peripheral VOIs differed significantly from those of the posterior region (C_VOI 8) (\(p\) < 0.05). The osteolysis volume increased in the order of the posterior (C_VOI 8), anterior (C_VOI 2), posterolateral (C_VOI 9), and posteromedial (C_VOI 7) regions. The maximum osteolysis volume was about 18-fold larger than the minimum one (36.3 \(\pm\) 6.5% and 1.8 \(\pm\) 1.6%, respectively, \(p\) = 0.00). Figure 3: Volumes of interest (VOIs) defined in the distal tibia and the proximal talus for measures of location, distribution, and volume of osteolysis. Blue, green, and red represent VOIs in distant-peripheral (D_VOIs 1–9), mid-peripheral (M_VOIs 1–9), and closest peripheral (C_VOIs 1–9) regions, respectively. Figure 4: The average distal tibial osteolysis volume of 12 patients. Significant differences are indicated by double asterisks (one-way ANOVA followed by [PERSON]’s LSD test, \(p<0.05\)). Single asterisks indicate a significant difference compared to the center region (C\_VOL_5, M\_VOL_5 or D\_VOL_5) (\(p<0.05\)). The osteolysis volume in the closest peripheral region of the talus was 1.6-6.9-fold larger than in the distant peripheral and mid-peripheral regions (\(p\) = 0.04). The average osteolysis volume in the closest peripheral region was 45.2 \(\pm\) 4.2% and did not differ significantly among the VOIs (C_VOIs 1-9) (\(p\) = 0.32). However, in the mid-peripheral region, a significant difference in the osteolysis volumes was seen among the VOIs (M_VOIs 1-9) (\(p\) = 0.00). The average osteolysis volume in the mid-peripheral region was 29.3 \(\pm\) 3.0%. The average volumes in the anteromedial region (M_VOI 1), anterior region (M_VOI 2), anterolateral region (M_VOI 3), medial region (M_VOI 4), and posteromedial region (M_VOI 5). The average total volume in the distal region (M_VOI 5) is 1.6 \(\pm\) 0.05  
(M_VOI 7) were significantly smaller than those in the center (M_VOI 5) and lateral (M_VOI 6) regions (\(p<0.05\)). The osteolysis volume was higher in the order of the center (M_VOI 5), lateral (M_VOI 6), posterolateral (M_VOI 9), and posterior (M_VOI 8) regions. The maximum osteolysis volume was about 8-fold larger than the minimum one (55.3 \(\pm\) 11.3% and 7.3 \(\pm\) 3.2%, respectively, \(p\) = 0.0). The osteolysis volume in the distant peripheral region differed significantly among the VOIs (D_VOIs 1-9) (\(p\) = 0.04). The average osteolysis volume was 6.6 \(\pm\) 0.9%. The anterolateral (D_VOI 3), medial (D_VOI 4), and posteromedial (D_VOI 7) volumes were significantly lower than those of the center (D_VOI 5) and posterior (D_VOI 8) regions (\(p<0.05\)). The osteolysis volume was generally higher in the order of the center (D_VOI 5), posterior (D_VOI 8), posterolateral (D_VOI 9), and anterior (D_VOI 2) regions. The maximum osteolysis volume was about 24-fold larger than the minimum one (11.6 \(\pm\) 4.1% and 0.5 \(\pm\) 0.3%, respectively, \(p\) = 0.00).