AB0081 THE ROLE OF LOCAL BISPHOSPHONATES IN THE PRESERVATION OF THE BMD IN THE ZONE OF SURGICAL BONE DEFECT (ANIMAL STUDIES)
Authors: A. Torgashin, S. Rodionova, A. Torgashina
Journal: Annals of the Rheumatic Diseases (2020)

Background: One of the reasons for failures in Arthroplasty is the preservation in the postoperative period in the bone adjacent to the implant of the prevalence of resorption over bone formation. The possibility of inhibition of resorption by bisphosphonates, including their local use in the composition of the biocomposite material, aggravates the situation due to the simultaneous oppression of bone formation. A low level of remodeling in these cases leads to a further loss of bone mass in the intervention zone. Objectives: To evaluate in the experiment the effect of bisphosphonates in the biocomposite material on the bone mass both in the surgical intervention zone and in the segment as a whole. Methods: The study was conducted as a comparison with the control. 60 females of white non-linear rats, body weight 130-150 g. were divided into 6 groups. In 3 groups, the defect of the tibia was filled with a biocomposite material in the form of a gel (patent No. 2325170) connected to various bisphosphonates Ibandronic acid (Bonviva), zoledronic acid (Aklasta), alendronate sodium (Fosamax) was used in conjunction with a non-demineralized lyophilized bone implant. Groups, the defect was filled with a non-demineralized lyophilized bone implant with biocomposite material without bisphosphonate, in the second control group, non-demineralized lyophils th e bone implants without biocomposite matreiala in tretey- defect is not filled. Assessment of bone mineral density (BMD) in the intervention area and in the segment as a whole was performed using X-ray densitometry (Hologic, Small Animals Program Performing and Analyzing Small Animal Studies). Results Comparison (simple dispersion analysis) of the MIC of all groups using bisphosphonates on the one hand, with the MIC of all control groups on the other hand, revealed significant differences (p &lt;0.002). Results: The analysis, using the paired t-test, the average MIC values in the combined group using bisphosphonates and the pooled control group, confirmed that the BMD in the zone of intervention in the bisphosphonate group was significantly higher than in the control: 0.320 ± 0.008 g / cm2, respectively, versus 0.285 ± 0.019 g / cm2 (p = 0.002). If the group was excluded from the analysis, where the defect was not filled, the tendency to differences remained: 0.320 ± 0.008 g / cm2 vs. 0.308 ± 0.002 g / cm2 (p = 0.11). Mean BMDs of the whole segment with the use of bisphosphonates also proved to be significantly higher than in the control, both with the inclusion in the analysis of the group without replacement of the defect, and with its exception. Thus, when all control groups were included in the analysis, the mean MIC values in the group with bisphosphonates were 0.30 ± 0.01 g / cm2 vs. 0.272 ± 0.12 g / cm2 (p &lt;0.001). When excluding from the analysis of the group without replacement of the defect, the MIC values were respectively: 0.307 ± 0.01 g / cm2 versus 0.285 ± 0.01 g / cm2 (p = 0.01). Conclusion: Relative to the control, an increase in BMD in the group using bisphosphonates excludes the possibility of their negative impact on the process of bone formation. The marked positive bone balance confirms the ability of bisphosphonates to maintain the remodeling mechanism at the physiological level. References: Local application of bisphosphonates, osteoplastic materials, biocomposite material, bone implant reconstruction, bone formation. Disclosure of Interests: None declared