Abstract： Objective To investigate the clinical efficacy of percutaneous kyphoplasty using the Sky Bone Expander system in the treatment of ache from senile vertebral bodies.Methods From August 2004 to February 2007,82cases(126 Vertebraes) of ache from senile vertebral bodies underwent pereutaneous kyplasty with sky bone expander system.During the operation the sinqle or double technique was applied and the expansion height was reduced with sky bone expander for bone cement injection.Patients were evaluated with Oswestry disability Index (ODI) and Visual Analogue Sere(VAS).Results Back pain was efectively relieved after the operation in all cases.Extravertebral leakage of bone cement were observed in 5 cases (6 vertebraes),4 cases had not symptome,1 case had die hard neuralqia between ribs,2 cases had toxigenic reaction for hearts.2 postoperative cases with neoplasm metastasis had more pain,but one day after,the pain died away.The postoperative follow-up ranged from 9to 37 months.with an average of 20.5 months.The postoperative ODI(P=0.007) and VAS(P=0.012) had better than preoperative.Conclusion Kyphoplasty using the Sky Bone Expander system is an efecfive and safe treatment for ache from senile vertebral bodies.Sky bone expander system provids siguificant pain relief effect,and can improve the kyphosis deformity and remain vertebral height.