Comparative Study of Two Surgical Techniques for Proximal Adjacent Segment Pathology after Posterior Lumbar Interbody Fusion with Pedicle Screws: Fusion Extension using Conventional Pedicle Screw vs Cortical Bone Trajectory-Pedicle Screw (Cortical Screw).

OBJECTIVE

To present a minimally invasive surgical technique using cortical bone trajectory pedicle screws (cortical screws [CS]) for adjacent segment pathology (ASP) after lumbar fusion surgery, and to thoroughly compare postoperative outcomes of surgical techniques with either a CS or conventional pedicle screws (PS) for ASP at a 1-year follow-up.

METHODS

Among 59 patients who underwent surgical treatment for proximal ASP after lumbar fusion surgery, 53 patients who met the study criteria (group A, 31 patients with conventional technique using PS; group B, 22 patients with minimally invasive technique using CS) were enrolled in the study. The primary outcome measure was the fusion rate at 1 year after surgery, and secondary outcome measures included patient satisfaction, clinical outcomes, radiologic outcomes, and surgical outcomes and complications.

RESULTS

Fusion at 1 year postsurgery was achieved by 90% of the patients in group A with PS and 91% of those in group B with CS (P > 0.99). Patient satisfaction at 1 month postsurgery (P = 0.03) and pain intensity within 1 month postsurgery (P = 0.04) were significantly better in group B compared with group A. Regarding surgical outcomes, blood loss was significantly less, operation time and length of hospital stay were significantly shorter, and the incision was significantly shorter n group B than in group A. Other clinical parameters and outcomes were similar in the 2 groups.

CONCLUSIONS

We suggest that a minimally invasive surgical technique using CS for ASP can be a viable alternative to a conventional surgical technique using PS.