To evaluate the radiological and clinical outcomes of intrapelvic anterior plate fixations for Day Classification Type II crescent fracture-dislocations of sacroiliac joints.

Ten patients who had undertaken the surgical treatment for the sacroiliac joint from 2006 to 2012 were enrolled in this study. All cases fell into Type II by Day Classification for sacroiliac joint injuries. For surgical treatments, the plate fixation through the intra-pelvic anterior approach was first performed for all cases and anterior ring fixation was performed in 4 cases with more severely displaced anterior pelvic ring injuries. Then, radiological and clinical evaluation was implemented.

The bone union was observed from all patients whom performed the surgical fixation. In the radiological results, 9 cases with the anatomic and nearly-anatomic reductions were observed. Out of the 10 cases which performed the rotational displacement analysis, there were 3 excellent cases, 6 good cases and 1 fair case. The 10 cases that performed the deformity index and vertical displacement analysis, less variations were observed in the anterior ring fixations after intra-pelvic anterior plate fixation group. According to the clinical results, 4 excellent cases, 3 good cases, and 3 moderate cases were observed.

In the Type II crescent fracture-dislocation of sacroiliac joint, the intrapelvic anterior plate fixation achieved satisfactory anatomical reductions, radiological stabilities and clinical results.