ABSTRACT
BACKGROUND:Poor implant anchorage in osteoporotic bone impacts its stability and requires the new solutions for the treatment. The augmentation technique with bone cements or bone substitutes is one strategy for the solutions. OBJECTIVE:To evaluate the transient stability of pedicle screw augmented using calcium sulfate cement in osteoporotic vertebral body. METHODS:Fresh calf lumbar vertebrae were selected to measure bone density, and then classified into four groups:the group by pedicle screw in normal vertebral body;the group by pedicle screw augmented using calcium sulfate cement in normal vertebral body;the group by pedicle screw in osteoporotic vertebral body;the group by pedicle screw augmented using calcium sulfate cement in osteoporotic vertebral body. Pedicle screw of equal specification was twisted into the tested pedicle of vertebral arch. The maximum axial screw pul-out strength and the maximum energy required to failure were recorded so as to assess the transient stability of pedicle screw augmented using calcium sulfate cement. RESULTS AND CONCLUSION:The maximum screw pul-out strength and the maximum energy required to failure were significantly less in osteoporotic vertebral body compared with normal vertebral body (P<0.05). The maximum screw pul-out strength and the maximum energy required to failure after augmentation using calcium sulfate cement were significantly increased (P<0.05). The maximum screw pul-out strength and the maximum energy required to failure after augmentation using calcium sulfate cement were identical between normal group and osteoporosis group. These results suggested that calcium sulfate cement could effectively increase the transient stability of pedicle screw. Calcium sulfate cement is effective in augmenting fixation in osteoporotic bone, and has potential in clinical application.
ABSTRACT
Objective To investigate the prevalence and risk factors of chronic kidney disease (CKD) in middle-aged and older adult population in Shanghai Pudong New District.Methods Two thousand residents aged 45 years and above were randomly selected for questionnaire survey and health check-up in Shanghai Pudong New District from July 2006 to October 2010.The laboratory examinations were also performed including the urine routine,urinary protein to creatinine ratio,serum creatinine,blood glucose and lipids.The glomerular filtration rate (eGFR) was estimated by simplified Chinese MDRD (modification of Diet in Renal Disease) equation.SPSS 13.0 statistical software was used for statistical analysis.Results Among 1905 residents who completed survey and examinations,the adjusted prevalence of albuminuria was 12.0％ (95％ CI:0.105-0.135) and of eGFR less than 60 ml · min-1 · 1.73 m-2 was 1.9％ (95 ％ CI: 0.172-0.213).The prevalence of CKD was 12.6％ (95 ％ CI: 0.112-0.142).Logistic regression analysis revealed that age (OR =1.043),hypertension (OR =2.272),diabetes mellitus (OR =1.233)and hyperuricemia (OR =1.003)were independently associated with CKD.Conclusions The prevalence of CKD in adult residents (≥45 years) from Shanghai Pudong New District is high.It is necessary to carry out early screening and to intervene risk factors of CKD in middle-aged and older residents.