Experimental Study On The Repair Of Femoral Head Necrosis Lesions Using Nano-hydroxyapatite/polyamide 66 Suppor

Purpose:Femoral head necrosis is a common clinical refractory disease that will eventually collapse the femoral head.Core decompression(core decompression)can prevent the progress of the early and middle stage femoral head necrosis and achieve the purpose of preserving the hip.However,the core decompression surgery,often due to the lack of mechanical support in the bone canal formed after core decompression,often results in a poor therapeutic effect.In comparison,nano-Hydroxyapatite/polyamide 66 scaffolds can effectively prevent the collapse of the femoral head and treat femoral head necrosis.Material and method:A finite element analysis model for femoral head necrosis based on gray value assignment to investigate the effects of medullary core decompression and nano-hydroxyapatite/polyamide 66 artificial bone support implantation on the biomechanics within the necrotic femoral head.And twelve adult male beagles were selected to establish the model of femoral head necrosis by liquid nitrogen freezing method,and the model results were identified by X-ray and MRI 4 weeks after modeling.The successfully molded beagles were randomly divided into the core decompression or nano-Hydroxyapatite/polyamide 66 scaffolds groups.After 8 weeks of core decompression and implantation with or without nano-Hydroxyapatite/polyamide 66 scaffolds,beagles were euthanasia,and femoral head samples were taken for micro-CT and histological examination Results:Finite element analysis showed that the implantation of nano-hydroxyapatite/polyamide66 artificial bone support significantly reduced the stress in the subchondral bone in the weight-bearing area of the femoral head and bone tract.Micro-CT results showed that the morphology of the femoral head and bone tissue in the nano-Hydroxyapatite/polyamide 66 scaffolds group was better than that in the core decompression group,and the nano-Hydroxyapatite/polyamide 66 scaffolds was partially replaced by bone tissue in the BMD,BV/TV,Tb.Th and Tb.Sp was higher than those in the core decompression group,while Tb.Sp was lower than those in the core decompression group.Furthermore,the histological result also verifies the alterations in micro-CT.In summary,the nano-Hydroxyapatite / polyamide 66 scaffold can provide better treatment than core decompression.Conclusion:nano-Hydroxyapatite/ polyamide 66 scaffold treats femoral head necrosis by providing mechanical support for the femoral head after CD and promoting bone tissue regeneration.