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

OBJECTIVE: 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). METHODS: 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. RESULTS: 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. CONCLUSIONS: We suggest that CS in single-level PLIF may be an alternative to PS.