Oblique-View Method Improves the Detection of cement leakage in Cement-Augmented Pedicle Screw Fixation.

INTRODUCTION

Cement-augmented pedicle screws (CAPS) are increasingly used in surgeries for osteoporotic vertebral fractures (OVFs); however, cement leakage (CL) remains a concern. Lateral-view (LV) fluoroscopy, the conventional method for monitoring cement injection, has limited sensitivity in detecting early leakage. The oblique-view (OV) method may provide improved detection, although its role in CAPS fixation remains unclear.

METHODS

Data from 116 patients and 535 screws who underwent CAPS fixation for OVFs using the LV or OV method were retrospectively compared. Patient demographics, surgical factors, and CL incidence were analyzed. A novel computed tomography-based grading system for segmental vein CL was developed as follows: grade 0 (no CL), grade 1 (≤10 mm), grade 2 (>10 mm without exceeding the anterior border or ≤10 mm beyond the anterior border), and grade 3 (>10 mm beyond the anterior border).

RESULTS

Baseline demographics and surgical factors were comparable between the groups. Overall, CL was observed in 56% of the patients and 20.9% of the screws. The screw-based incidence of CL was significantly lower in the OV group than in the LV group (15.0% vs. 22.9%, p=0.047), although the CL severity did not differ. Intraoperative CL detection was significantly more effective in the OV group than in the LV group (37.2% vs. 91.7%, p<0.01), including grade 1 and 2 cases, and 67% of leakages were identified within 0.4 mL of injection. No major complications, such as pulmonary embolism, occurred.

CONCLUSIONS

The OV method enhanced the intraoperative detection of CL during CAPS fixation for OVFs, facilitating the early recognition of minor leakage and reducing the overall leakage frequency without increasing the incidence of severe complications. These findings support the clinical utility of the OV method and the proposed grading system, which may guide safe cement injection in patients with osteoporosis.