Comparative Study Of Cement Perfusion Pressure For Vertebroplasty And Kyphoplasty

Objective: To observe the dynamic variation of cement perfusion pressure during Vertebroplasty and Kyphoplasty.Methods: First, a set of perfusion pressure measuring device was designed and debugged to record the cement perfusion pressure for Vertebroplasty and Kyphoplasty. Second, certification experiment was done twice respectively under condition of 0.25mm/min、40N,0.25mm/min、60N and 0.5mm/min、60N. Totally, six experiments were done to get the relationship between the voltage difference and pressure. Third, ten vertebral specimens were randomly divided into two groups: PVP group(A1, A2, A3, A4, A5) 、PKP group(B1, B2, B3, B4, B5). In the room temperature of 20℃, bone cement filling volume was 2.4 m L and perfusion time was 48 s. Then the cement was injected uniformly and the cement perfusion pressure for Vertebroplasty and Kyphoplasty was recorded by the set of perfusion pressure measuring device. Last, the CT scan was done to observe the dispersion of cement in the vertebral body.Results: 1.In the certification test, the voltage difference has a linear relationship with the pressure. With the increase of the voltage difference, the pressure also increases, F(N)=440×U(V). 2. In the room temperature of 20℃ and velocity of 0.05 m L/s, the average and maximum perfusion pressure of the first and second canula injection for Vertebroplasty were 12.41±2.42 N, 19.89±3.82 N, 19.81±3.03 N, 33.44±4.86 N. And the average and maximum perfusion pressure of the first and second canula injection for Kyphoplasty were 6.33±2.05 N, 10.74±3.32 N, 9.42±1.69 N, 18.18±1.77 N.Conclusion: 1. Cement perfusion pressure was lower in in the Kyphoplasty when compared with Vertebroplasty. 2. During Kyphoplasty, the cement filled the cavity due to balloon expansion at first. And the dispersion of cement in Kyphoplasty was more uniform comparing with Vertebroplasty. So, the rate of cement leakage was lower in Kyphoplasty.