Sheep Lumbar Implant PA66 / N-HA Fusion After The Initial Stability

Back ground:The materials with excellent Biological activity and biomechanical properties can be made into various kinds of implants, and they can achieve better clinical results, so they can replace old equipments and have broad application prospects.Objective:(1)To make cages for sheep lumbar by PA66/n-HA material.(2) To compare the primary lumbar segment stability when one cage or two cages implanted.(3) Analysis the Stress and strain of lumbar vertebrae by finite element analysis.Materials and methods:(1) Achieved the size of sheep lumbar vertebrae by CT scan and determined the size of cages by MIMICS, then designed and made the cages for this study.(2)Compared the primary lumbar segment stability of one cage, two cages and Autologous bone graft groups, with or without screw fixation.(3)Analyzed the Stress and strain of lumbar vertebrae by finite element analysis.Results:(1) Designed and produced two types of cages for sheep lumbar.(2) In vitro tests suggested that cages provide better stability than Autologous bone graft, especially two cages.(3) Some results of finite element analysis is similar to the mechanical tests quantitatively. Finite element analysis can make better understanding of mechanical changes in vertebral body after fusion.Conclusion:Cages made of PA66/n-HA could provide better primary lumbar segment stability than Autologous bone graft, and with more studies, they may be used in clinics.