Experimental research on irregular 45S5 bioactive glass granules with 3 different sizes in repairing bone defects

GAO Peng; WANG Zhen; ZHANG Hao-qiang; WU Chang; LIU Yun; XIAO Xin

doi:10.3969/j.issn.2095-252X.2015.01.014

Abstract：Objective To evaluate the effects of irregular 45S5 bioactive glass granules with 3 different sizes in repairing bone defects.Methods A total of 24 adult New Zealand white rabbits were randomly assigned into 4 even groups, with 12 hind legs in each group. In group A, 90-300 μm granules were implanted and 300-500 μm granules were implanted in group B, and while the rabbits in group C were implanted with 500-720 μm granules. Nothing was implanted in Group D, which was taken as the control group. The defects with the depth of 12 mm and the diameter of 6mm were made in bilateral femoral condyles of each rabbit. The sample was taken at 6 and 12 weeks after the operation. The osteogenic potential and biodegradation property of irregular bioactive glass granules with different sizes were evaluated through the general observation, X-ray and Van-Greson staining ( VG staining ).Results All the rabbits woke up at 2-4 h after the operation, and their activities were restored, with normal bowel and bladder function. They were sensitive to external stimulation. Primary wound healing was achieved in all the rabbits, without inflammatory responses or abnormal soft issues. No obvious effusion was noticed in the knee joint cavity, and the synovium was smooth and complete. There were no residual granules. No extra bone destruction was found around the femoral condyle, and there were no abnormal inlfammatory and ifbrous masses. At 6 weeks after the operation, new bone began to grow towards the internal materials in groups A, B and C, but there was no new bone formation in group D, except for some granulation tissues. At 12 weeks after the operation, a signiifcant increase in the bone mass was detected in group A, B and C, and most bone defects got repaired. The mature bone trabecula could be seen. At 6 weeks after the operation, the Lane-Sandhu X-ray scores were ( 4.827±0.277 ) points, ( 5.128±0.448 ) points and ( 7.104±0.477 ) points in groups A, B and C, which were higher than ( 0.831±0.081 ) points in group D (P<0.05 ). The score in group C was higher than that in groups A and B (P<0.0001 ). There were no statistically signiifcant differences in the Lane-Sandhu X-ray score between group A and group B (P=0.193 ). At 12 weeks after the operation, the Lane-Sandhu X-ray scores were ( 8.011±0.159 ) points, ( 8.023±0.197 ) points and ( 10.974±0.106 ) points in groups A, B and C, which were signiifcantly higher than that at 6 weeks after the operation (P<0.0001 ). The score in group D was ( 1.397±0.262 ) points, which was lower than that in groups A, B and C (P<0.05 ). The score in group C was higher than that in group A and B (P<0.0001 ). The scores in group A and group B were almost the same (P=0.805 ). At 6 weeks after the operation, the percentages of new bone formation in groups A, B and C were ( 10.837±0.856 ) %, ( 10.762±1.008 ) % and ( 17.399±0.515 ) %, which were greater than ( 1.048±0.127 ) % in group D (P<0.0001 ). The percentage in group C was greater than that in groups A and B (P<0.0001 ). The percentages in group A and group B were almost the same (P=0.704 ). At 12 weeks after the operation, the percentages of new bone formation were ( 20.681±0.513 ) %, ( 20.426±1.675 ) % and ( 32.961±1.583 ) % in groups A, B and C, which were signiifcantly greater than that at 6 weeks after the operation, and the differences were statistically signiifcant (P<0.001 ). The percentage in groups A, B and C were greater than ( 2.108±0.131 ) % in group D (P<0.0001 ). The percentage in group C was greater than that in groups A and B (P<0.0001 ). No statistically significant differences existed in the percentage between group A and group B (P=0.154 ). At 6 weeks after the operation, the percentages of remaining materials were ( 28.483±0.489 ) % and ( 29.045±0.818 ) % in groups A and B, which were greater than ( 22.802±1.151 ) % in group C (P<0.0001 ). No statistically signiifcant differences existed between group A and group B (P=0.154 ). At 12 weeks after the operation, the percentages of remaining materials were obviously reduced in groups A, B and C, when compared with that at 6 weeks after the operation. There were statistically signiifcant differences (P<0.001 ). The percentage was ( 14.729±0.494 ) % in group C, which was far less than ( 21.104±0.924 ) % and ( 21.553±0.854 ) % in groups A and B (P<0.0001 ). No statistically signiifcant differences existed in the percentage between group A and group B (P=0.298 ).Conclusions The biodegradation property is found in irregular bioactive glass granules with the sizes in 90-300 μm, 300-500 μm and 500-720 μm, which can grow into bone tissues during the biodegradation process. The bioactive glass granules with the size in 500-720 μm have better osteogenic potential and biodegradation property, which can be a good choose in repairing lacunar bone defects.