Comparative Research Of Cement Leakage And Related Influencing Factors:vertebroplasty Versus Kyphoplasty

Objective: With the development of percutaneous vertebroplasty and percutaneous kyphoplasty,the treatment of osteoporotic vertebral compression fractures is better than before. These two operations can relieve the local pain effectively and enhance the stability of the spine. However,the related complications appeared: cement leakage,pulmonary embolism.The reports about vertebroplasty and kyphoplasty are not unified. Some reports that Vertebroplasty and Kyphoplasty can effectively relieve osteoporotic vertebral compression fractures in patients with pain.but the cement leakage of kyphoplasty was lower than the rate of vertebroplasty. The other report that the cement leakage of kyphoplasty was higher than the rate of vertebroplasty The purpose of this study is to test the differences of cement leakage rate,the distribution and reasons of leakage between vertebroplasty and kyphoplasty technique on vertebral body specimens and discuss the clinical value.Methods: Six sets of embalmed samples from the same area with the same race,sex and age(60±1 years) were enrolled in our study. The fractures, tumors and congenital malformation were ruled out by X-ray. T10-L5 centrums were dislodged and dissociated into the single vertebral body, free into 48 individual vertebrae from the intervertebral disc and vertebral joints, preserving the anterior and posterior longitudinal ligament. fter the bone mineral density(BMD) was measured,40 vertebral bodies with similar bone density and volume were selected from the 48 vertebral bodies.The 40 vertebral bodies were randomly divided into two groups(group A and group B). The whole vertebral bodies were placed between two nickelclads,and loaded vertically with 5mm/min until the vertebral bodies were yielded,20 of them were treated with vertebroplasty(group A), the other 20 specimens were proceeded to kyphoplasty procedure(group B).All the vertebral bodies were injected with the same manufacturers, the same viscosity, the same amount of cement. After surgical treatment,cement leakage and the distribution of cement were identified with reference of CT scan and recorded. Statistical software were employed to analyze the data, and differences were regarded as statistically significant when P < 0.05.Results: All specimens were osteoporotic vertebral bodies. the density of the specimens were 0.374-0.640g/cm2 8 cases(40%)of cement leakage were observed in 20 specimens of group A and 3 cases(15%)were found in group B respectively. χ2 test was used for the comparison of leakage rate, there was no statistically significant difference(P=0.077,P>0.05). But it could show a trend:the rate of leakage after kyphoplasty was lower. There were 3 vertebral bodies leakage to the front side of the vertebral body in the group A,2 to the lateral of the vertebral body,2 to the lateral and the forward side of the vertebral body at the same time,1 to the upper endplate; There were 2 vertebral bodies leakage to the front side of the vertebral body in the group B,1 to the upper endplate.The CT showed: cement distribution were more well-distributed in group B.Conclusion: Using a Kyphoplasty technique can gain lower leakage rate than vertebroplasty in terms of bone cement leakage which indicate that the safety of Kyphoplasty technique may higher. As a result of the operation process of kyphoplasty was complex,and the operation time was longer,many doctors chose Vertebroplasty. Therefore,this increased the risk of cement leakage. This experimental results showed that the security of kyphoplasty was higher than vertebroplasty. But special attentions should be payed on the pressure of balloon and the distribution of bone cement during surgical procedure. The application of high viscosity bone cement can prevent the leakage of cement effectively. This experiment in vitro and the experimental results improve the reference value for clinical application. But in vitro experimental study and clinical application still exist differences. Clinical effect of current VP and KP for the treatment of osteoporotic vertebral compression fractures in the endwhich is better still needs a large number of clinical randomized controlled study.