Experimental study to investigate a potential model for improved osseointegration in sickle cell bone disease patients with avascular necrosis

Introduction/objectives: It is well documented that implant loosening rate in sickle cell disease patients is higher than seen in patients with THR from other indications. The Hypoxic inducible factor(HIF) - is activated in the microcellular hypoxic environment and this through a cascade of other enzymatic reactions promotes the activity of other factors and further help enhance angiogenesis and osteogenesis. The aim of this study was to investigate and propose a potential model for investigating osseointegration in a hypoxic microcellular environment using osteoblasts(MG63). Methods: Human MG63 osteoblastic cells were cultured under normoxia and hypoxic conditions (20%; and 1% oxygen saturation) for 72 hours under two different condition- with and without cobalt chloride. The samples cultured under normoxic condtions without cobalt chloride acted as control. Using qualitative polymerase chain reaction-(qPCR) - HIF expression was assessed under the above conditions in relation to the control. Results: The results showed there was significant expression of the HIF 1 alpha protein under hypoxic condition with cobalt chloride in comparison with the control samples- all at 72hours incubation. Mann-Whitney U test was used to deduce level of significance of fold change.(p=0.002; <0.05). This was deemed as there being a significant difference in the level of expression of HIF compared to the control. Conclusion: The results show that the hypoxic inducible factor can be expressed using the above tested experimental invitro-model with significant results which can be a foundation for further research into improving hip implant prosthesis design to help enhance osseointegration in sickle cell disease patient with AVN.