The Fabrication Of The Injectable Water Absorb And Inflation PMMA Bone Cement

With the increasing of aging population in our country,the question of osteoporosis becomes particularly serious in recent years and Osteoporosis vertebral compression fractures has become one of the main challenges for the orthopaedic clinic.Bone cement is a kind of common medical materials which is usually used in orthopedic surgery,bone cement can be combined between bone and implant strengthened and avoid the pain from the loose of the bone with the implant,so it can solve the problem of the osteoporosis vertebral compression fractures well.Although acrylic bone cement has been widely applied to clinical,but it does exists many problems.Methyl methacrylate in the polymerization process will produce a certain volume contraction,the bone and implant cannot be fixed firmly and bone cement even fall off from the bone,volume shrinkage will produce residual stress which leading to bone cement interface,micro cracks will affect the long-term stability of the prosthesis;the modulus of elasticity of PMMA bone cement is higher than that of bone,it can produce friction and wear to normal bone even cause secondary fractures;In addition,PMMA bone cement can cause burns to the normal part of the human body because the large amount of heat in the polymerization process.So the improvement for the PMMA bone cement becomes more and more important.In view of the various problems of PMMA bone cement,this paper first introduces the PMMA/PAAS water absorbed and inflation bone cement with PA AS water absorbed resin fibers.This kind of bone cement has good injectable ability,water absorption and expansion ratio.Second,we choose acrylic acid containing a hydrophilic group copolymerized with methyl methacrylate by the solution polymerization to make the PMMA-PAA microspheres which can absorb water,the PMMA-PAA microspheres and PMMA powder was used as the solid phase and MMA was used as the liquid phase.In 37 ℃ and 100%relative humidity environment the PMMA chemical grafting AA water absorbed and inflation bone cement can be obtained.The PMMA chemical grafting AA water absorbed and inflation bone cement has good injection and the water absorption and expansion rate,and this kind of bone cement has the same cytotoxicity with the PMMA bone cement,also has good biocompatibility.The PMMA/PAAS water absorbed and inflation PMMA bone cement and PMMA chemical grafting AA water absorbed and inflation bone cement both solve the problems of PMMA bone cement,so they have extensive application prospect in clinic.