Abstract:

Objective　To measure anatomical parameters of the guide device for antegrade lag screw fixation of the fractures in the posterior column of acetabulum.　Methods　17 females and 14 males semi pelvic bony specimens were collected for this clinical anatomic study. After successful implantation of the antegrade lag screw into the posterior column of acetabulum, the screw entry point and entry angle of inclination were separately measured and statistically analyzed.　Results　The average distance between the entry point and the arcuate margin was (0.96±0.32) cm in female and (0.92±0.16) cm in male (P>0.05), while the distance between the entry point and the sacroiliac joint front was (2.43±0.66) cm in female and (1.87±0.26) cm in male (P<0.05). The average retroversion angulation of screw was (59.68±6.28)°in female and (56.75±3.22)°in male (P>0.05）, while the extraversion angulation was (41.27±2.76)°in female and (34.31±2.78)°in male (P<0.05).　Conclusions　The results of our measurement can contribute to design of guide device for antegrade lag screw, which could improve the success rate and accuracy of the screw implantation in the posterior column of acetabulum, reduce the surgery risk, and minimize operative trauma.

Key words: Pelvis, Acetabulum fracture, Antegrade lag screw, Entry point, Angle of inclination, Applied anatomy