Posterior Sacroiliac Joint Fusion for Severe Sacroiliac Joint Disorders: A Technical Note on Surgery Using Transarticular Cylindrical Cages Combining Posterior Instrumentation and its Surgical Outcomes.

INTRODUCTION

Anterior sacroiliac joint (SIJ) fusion has been performed for severe SIJ disorders and has demonstrated stable long-term outcomes; however, its relatively high invasiveness remains a significant concern. To overcome this limitation, we developed a posterior fusion using transarticular cylindrical cages combined with posterior instrumentation. This study describes the posterior SIJ fusion technique and evaluates the surgical outcomes.

TECHNICAL NOTE: An S1 pedicle screw is inserted toward the sacral promontory, and two S2 alar-iliac screws are placed in the ilium. All three screws are connected to a rod. One or two cylindrical cages filled with cancellous bone are inserted into the SIJ via a trans-iliac bony channel lateral to the posterior superior iliac spine to promote fusion in the anterior-superior portion of the SIJ while preserving the posterior sacroiliac ligaments. Seventeen patients (20 joints) with SIJ disorders were followed for a mean period of 53±23 months. Bone union was obtained in 93.3% of joints. Postoperative SIJ pain evaluated by the visual analog scale significantly improved from 87±18 to 24±25 mm (p<0.0001), and activities of daily living, assessed by the Denver SIJ Questionnaire, improved from 32±11 to 18±16 (p=0.0002).

CONCLUSIONS

The posterior SIJ fusion technique using transarticular cylindrical cages via a trans-iliac bony channel combined with posterior instrumentation resulted in favorable postoperative outcomes in patients with SIJ disorders.