An experimental study of percutaneous vertebroplasty using instruments and drugs made in China / 中华放射学杂志

ABSTRACT

Objective To evaluate the efficacy of percutaneous vertebroplasty(PVP) using instruments and drugs made in China, and to provide the data for the clinical application Methods Polymethylmethacrylate(PMMA) without adding contrast was classified into 3 groups according to the ratio of powder/liquid as 2∶1,3∶2,1∶1,PMMA with contrast was also classified into 3 groups according to the ratio of powder/liquid/contrast as 2∶1∶1,3∶2∶1,1∶1∶1 There were 6 groups totally The periods and temperature of polymerizing process were measured The PMMA specimens of different group were made,with the diameter of 1 0 cm, height of 3 0 cm The density was determined in X ray pictures and mechanical testing with universal testing machine was performed PVPwas performed in the spines of 3 human cadavers with transpedicular route under fluoroscopic control The PMMA was injected into vertebra at an interval of one vertebra from T4-L4, 7 vertebra were injected on each cadaver The injected volume was recorded The spines were dissected into 42 single vertebrae, with all soft tissues removed Overall,21 pairs of adjacent vertebrae were subjected to axial compression in an universal testing machine The cranial vertebra of each pair was injected with PMMA, the caudal one served as a control Results Lower temperature was observed in the PMMA groups with adding contrast than those without adding contrast during the polymerizing process, the average temperature in the PMMA group with the ratio of powder/liquid/contrast as 3∶2∶1 was 67 4℃ There was significant X ray density difference between the groups with contrast and corresponding groups without contrast ( t = 20 00, t = 20 00, t = 22 86, P 0 05) The group with ratio of power/liquid/contrast 3∶2∶1 was (127? 4 70) s in the period of the paste, and the ultimate compressive strength (mPa) was 47 23 The punctures were successfully reached in all vertebra The injected PMMA average volume was 5 ml in the thoracic vertebra and 7 5 ml in the lumbar vertebra PMMA leaking into adjacent paravertebral tissue was demonstrated in 3 of 21 vertebrae The ultimate compressive strength of the vertebrae without PMMA injection in the 3 groups was 3 28,3 63,and 3 69, respectively The ultimate compressive strength of the injected PMMA vertebrae in the 3 groups was 4 52,4 73,and 4 81, respectively The ultimate compressive strength was significantly higher in the injected PMMA vertebrae than that in the vertebrae without PMMA injection( t =3 17,3 55,3 99, P