Anatomic Consideration of Safe Zone in Plate-Screw Fixation of the Anterior Column of the Acetabulum

Ihn, Joo Chul; Kim, Poong Taek; Park, Byung Chul; Kim, Byung Guk; Kim, Hee Soo

Abstract

PURPOSE: To evaluate the configuration of the anterior column of the acetabulum and to develop a safe path for screw placement for it. Materials and methods: Ten embalmed cadaveric adult bony-hemipelvis specimen were obtained. Each specimen was sectioned at 1cm intervals, beginning at the level of the inferior border of the acetabulum. The plane of the cross-section was perpendicular to the anterior column. The projection of the medial acetabular boundary on the anterior column was determined by analysis of each cross-section.
RESULTS
The average width of the anterior column at 1.0, 2.0 and 3.0 cm superior to the inferior acetabular boundary was 27.9+/-4.3, 31.7+/-3.6 and 35.2+/-4.9 mm, respectively. At 1.0 cm superior to the inferior margin of the acetabulum, the average medial angulation for 0.5, 1.0 and 1.5 cm entry points lateral to the pelvic brim were 26.7+9.1 degree, 37.9+/-6.5 degreeand 46.1+/-5.0 degree, respectively. At 2.0 cm superior to the inferior acetabular margin, the corresponding average medial angulation for 0.5, 1.0 and 1.5 cm entry points were 20.4+/-6.2 degree, 30.4+/-5.6 degree and 41.0+/-5.0 degree, respectively. At 3.0 cm superior to the inferior acetabular margin, these angles were found to be 19.5+/-3.8 degree, 30.5+/-5.1 degree and 40.8+/-4.6 degree, respectively.
CONCLUSIONS
This anatomical analysis of the acetabulum shows that it is possible to develop a safe path for screw placement into the anterior column. And the data could be a useful guide line for plate and screws fixation of the anterior column of the acetabulum.