Comparative Study of Cortical Bone Trajectory-Pedicle Screw (Cortical Screw) Versus Conventional Pedicle Screw in Single-Level Posterior Lumbar Interbody Fusion: A 2-Year Post Hoc Analysis from Prospectively Randomized Data

Abstract

The aim of this study was to report 2-year follow-up outcomes of posterior lumbar interbody fusion (PLIF) with cortical bone trajectory-pedicle screw (CS), in terms of fusion rates, clinical outcomes, surgical outcomes, and complications, and to compare these outcomes with outcomes for PLIF with conventional pedicle screw (PS). We enrolled 79 patients and randomly assigned them to 2 groups (group A with PS, 39 patients; group B with CS, 40 patients), and finally 37 and 35 in group A and B were analyzed in the study. The primary outcome measure was the fusion rate, evaluated by dynamic radiographs and computed tomography scans. Secondary outcome measures included 1) patient satisfaction; 2) clinical outcomes measured with pain intensity using a visual analog scale, the Oswestry Disability Index, and 12-Item Short Form Health Survey; 3) radiologic outcomes; and 4) complications. At 2-year follow-up, the fusion rate was comparable between the PS and CS groups (35 of 37 patients in the PS group; 32 of 35 patients in the CS group; P > 0.99). The patient satisfaction rate at the 1-month follow-up was significantly greater in the CS group than in the PS group (P= 0.03); however, there was no significant difference between the groups at the 1-year and 2-year follow-ups. Clinical outcomes, radiologic outcomes, and related complications revealed no significant differences in both groups within 2 years postoperatively. We suggest that CS in single-level PLIF may be an alternative to PS.