Pathological Mechanisms Of Percutaneous Kyphoplasty Adjacent Vertebral Fracture

ObjectiveIn recent years,with the continuous increase of population life and the further trend of aging,osteoporosis patients gradually increased.Osteoporosis(osteoporosis,OP),with bone loss,decreased bone strength,bone trabecula and micro structure degradation characteristics,resulting in increased bone fragility,minor trauma or no trauma cases are easy to systemic metabolic bone disease,fracture.Osteoporosis can occur in different gender and age,but more common in postmenopausal women and elderly men;mainly divided into primary and secondary categories,senile and idiopathic type of primary osteoporosis is divided into postmenopausal.Osteoporotic vertebral compression fractures(osteoporosis vertebral compression fractures,OVCFs)is one of the common complications of osteoporosis,which seriously affects the quality of life and health of patients.In recent years,emerging minimally invasive treatment method,provides a new choice for the treatment of OVCFs,while improving the quality of life of patients,but OVCFs patients with percutaneous kyphoplasty found adjacent vertebral / a vertebral fracture(jumping fracture)of the higher incidence.The study by comparing two groups of vertebrae of osteoporotic vertebral compression fractures,observation of vertebral fractures related to the occurrence of vertebral augmentation,pathological mechanisms of percutaneous kyphoplasty adjacent vertebral fracture.MethodsThe acquisition of fresh adult sheep(male and female each 4,kg.average weight 50-60 50 kg,were the same day massacre),X-ray radiographs to exclude congenital malformation,tumor / fracture,bone mineral density was measured by dual energy X-ray bone density of each specimen was used.Simulation of vertebral osteoporosis with ethylenediaminetetraacetic acid two sodium in vitro decalcification,short-term manufacturing of osteoporotic vertebral compression fracture model,remove vertebral specimens on both sides of the muscle,soft tissue and rib is connected with the thoracic specimens,third thoracic vertebra and ninth thoracic vertebral bodies(T3-T9),tenth thoracic vertebra and fourth lumbar vertebral bodies(T10-L4)respectively a group of 16 groups of the experimental specimen preparation.Each of the intermediate vertebrae(T6 or L1)resulted in compression fractures,and PKP was used to recover the height of the compressed vertebral body.From both ends of the vertebral body,using artificial spinal test system(Mini Bionix)and multi channel test system for spinal specimens,flexion / extension,axial load,rotation,and fatigue test,obtained the static and dynamic test data,statistical analysis,through the observation of two groups of pyramidal bone fracture incidence,cancellous bone maximum von Mises stress,vertebral cortical bone maximum von Mises stress,erector spinae,intervertebral disc endplate pressure,maximum von Mises stress and the image of typical cases to analyze the pathological mechanism of percutaneous kyphoplasty adjacent vertebral fracture.ResultsT10-L4 group of vertebral fracture incidence of cancellous bone and the maximum von Mises stress and vertebral cortical bone maximum von Mises stress was higher than that in group T3-T9,with statistical significance(P<0.05);in order to stay upright,T10-L4 group of the erector spinae will be significantly higher than T3-T9 group,there was statistical significance(P<0.05);and the pressure of disc group T10-L4 von Mises maximum endplate difference force and T3-T9 group(P<0.05).ConclusionAfter PKP,the fracture of the vertebral body is related to the stress of the vertebral body and the vertebral body,which can guide the clinical prevention and treatment.