The expansion of transverse diameter of pedicle following screw implantation / 中华骨科杂志

ABSTRACT

Objective To observe the expansion of transverse width of post screw-implantation in the pedicle and assess the effect of the relative diameter and BMD on the expansive rate. Methods There were 48 vertebral bodies, and 96 pedicles, obtained from 4 human cadaveric T2～L1 specimens (the mean age of 41 years). The BMD(A), pedicle width (B) and height were measured respectively. According to groups of BMD(A10.44～0.52 g/cm2;A20.52～0.70 g/cm2;A30.70～0.92 g/cm2 and the relative diameter(screw/pedicle)(B140%～55%;B255%～70%;B370%～85%), the tests were classified into 9 groups (A1B1?A1B2 ?A1B3?A2B1?A2B2?A2B3?A3B1?A3B2 and A3B3). The implantation procedure was carried out under the uniform standard. Results The number of valuable date was 85, while 11 dates were excluded, including 4 burst pedicles in A3B3 group. According to the statistical analysis, the pedicle width was expanded after implantation. The expansive rate of pedicle width was influenced significantly by the relative diameter and BMD(P