| There are many questions in the implants which are used in the antecervical surgeries now.Many patients have complication and complaint after surgeies.The material of nano-hydroxyapatite/polyamide(n-HA/PA) is the new bone restore material that has independence intellectual property rights and international precession movement.The nano-hydroxyapatite/ polyamide(n-HA/PA) composite cervical vertebra scaffold has a extensive application perspective in bone renovation and organization engineering.We test its extraorgan biomechanics property in this experimentation.And provid evidence to clinical application.The material of nano-hydroxyapatite/polyamide(n-HA/PA) is the new material proved to be used in the weight-bearing site of defective incomplete bone.The hydroxyapatite ceramic of the material by means of nanometer size accretes the polymeride base.Polyamide 66 has intensity,tenacity and asepsis.The biomechanics property of the material is near to the human bone.It can obviate stress shielding.That can cause bone resorption,implants loosening and implants nonfusion.We cooperated with the Material Inst of NUUA.We developped the new bone frame pedestal system used in ante cervical surgery.The experimentation emphasize to study and research the material biomechanics property.The preparation of the nano-hydroxyapatite/polyamide(n-HA/PA) composite cervical vertebra scaffoldsTake the hydroxyapatite ceramic to 20%serous fluid,then add liquid macrogol to dissolve and agitate uniformity.The liquid thoroughly diffuse in the dimethyl acetamide. Dissolve PA66 in methanol and excessive physical exertion agitating two hours. Slow-moving drop PA66 into dispersal n-HA serous fluid.Use deionized water and alcohol scrubbing the mixed solution many times,then dry it.We get mixed solution.Eventually per-mode-mode and vacuo heating,get the material.Biomechanics studyIn this study eight flesh frozen human cadaveric cervical spines(C1-T1) were used to make model of the anterior cervical subtotle vertebrectomy and intervertebral fusion(C5) withplate screw fixation,On the basis of digital correlation technique,The specimens were tested in a nondestryctive manner load,it produceaxial compression and the following six degrees of freedom:flexion,extension,torsion right/left and lateral bending right/left.Data were captured using CCD and an adjacent desktop computer.Eight fresh-frozen human cadaveric spines(C1-T1) were inspected by plain radiographs to ensure specimens the absence of structural spinal disorders,previous neoplastic disease,or spinal surgery.In addition,these images confirmed the correct anatomic sagittal and coronal aligmnment of the specimen.The bio-stress were measured assigned as normal group(N group).Then the specimens were divided into two groups:autogenous iliac bone group(B group) and cervical vertebra scaffold group(A group).The anterior cervical subtotle vertebrectomy was performed.The autogenous iliac bone grafts were implanted and fixed with plate and screw in the autogenous iliac bone group,while the n-HA/PA composite cervical vertebra scaffolds were implanted and fixed with plate and screw in the cervical vertebra scaffold group.The biomechanics of the specimens were measured by WD-5 electronic universal testing machine.The axial stiffness,strength,and rotation capability of cervical vertebrae in the three groups were observed.The axial stiffness,strength,and rotation capability of cervical vertebrae in the autogenous iliac bone group were significantly lower than that in the normal and cervical vertebra scaffold groups(P＜0.05).After the two ways of surgeries,the near segments will produce stress concentration and more reactiveness.The near disci intervertebrales will be cataplasis.But the A group will be less than the B group (P＜0.05).Conclusion:After the anterior cervical subtotle vertebrectomy surgery,use the material of n-HA/PA can elevate the stability of the spine effectively,decrease the cataplasis of the near segments.It has wide perspective。... |
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