Comparison of Implant Failure between Cement Augmented Cannulated Pedicle Screws and Solid Pedicle Screws and Associated Risk Factors in Lumbar Fusion Surgery: A Pilot Study

Abstract

Study Design: Retrospective pilot study Objectives: To compare and analyze the rate and risk factors of implant failure according to the use of solid pedicle screws or cement augmented cannulated pedicle screws in lumbar fusion surgery. Summary of Literature Review: In previous studies, the use of cement augmented cannulated pedicle screws was found to improve the pull-out strength and to reduce the risk of implant failure in patients with osteoporosis. However, the clinical risk factors for implant failure have not been established. Materials and Methods: From January 2016 to December 2018, 177 patients with spine fracture and degenerative thoracolumbar disease were included in a retrospective study, and the patients underwent spinal fusion surgery using pedicle screws. Solid pedicle screws were used in 118 patients and cement augmented cannulated pedicle screws were used in 59 patients. During the follow-up period, simple radiography and computed tomography were performed to evaluate cases of implant failure, including pedicle screw loosening, migration, and pull-out, and to analyze risk factors for implant failure. Implant failures were observed in 21 patients (11.9%, 21/177) during the follow-up period. Of the 21 patients with implant failure, 18 were in the solid pedicle screw group (15.3%, 18/118), and 3 patients were in the cement augmented cannulated pedicle screw group (5.1%, 3/59). The difference was statistically significant (p<0.05). Age over 65 years, osteoporosis, autoimmune disease (rheumatoid arthritis, systemic lupus erythematosus, etc.), chronic kidney disease, and steroid use (<0.05) were statistically significantly more common in patients who experienced implant failure. In a multiple logistic regression analysis, age over 65 (odds ratio, 4.47; p=0.032), osteoporosis (odds ratio, 3.68; p=0.017), autoimmune disease (odds ratio, 3.59; p=0.039), and chronic kidney disease (odds ratio, 4.67; p=0.043) were statistically significant risk factors for implant failure. Conclusions: Patients underwent thoracolumbar fusion who were over 65 years of age, had osteoporosis, chronic kidney disease, or autoimmune disease showed a high implant failure rate. The use of cement augmented cannulated pedicle screws might be an effective method to significantly decrease the likelihood of implant failure in patients with these risk factors.