2020, Vol.27, No.3

Journal of Korean Society of Spine Surgery 2023 KCI Impact Factor : 0.03

pISSN : 2093-4378 / eISSN : 2093-4386
https://journal.kci.go.kr/krspine

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. Results: 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.

Study Design: Feasibility study. Objectives: To evaluate the association between L1 slope and thoracolumbar spinal parameters of sagittal balance in cases of osteoporotic vertebral fracture. Summary of Literature Review: Recently, interest has emerged in the sagittal parameters of the thoracolumbar spine in cases of osteoporotic vertebral fracture. Materials and Methods: Eighty-five patients were enrolled in this study, including 36 patients with recent osteoporotic vertebral fractures (group 1) and 49 patients who did not have vertebral fractures (group 2). Radiographic parameters including L1 slope, C7 plumb line (C7 PL), sagittal imbalance (C7 PL >50 mm), lumbar lordosis, thoracic kyphosis, pelvic tilt, S1 slope, local kyphotic angle were evaluated on standing lateral radiographs of the whole spine. We analyzed correlations between L1 slope and these parameters. Results: Of the sagittal parameters of the spine, the mean L1 slope, C7 PL, thoracic kyphosis, lumbar lordosis, S1 slope, pelvic tilt, and local kyphotic angle were 10.43°, 92.43 mm, 29.30°, 30.31°, 25.27°, 27.27°, 9.90° in group 1 and 9.41°, 68.50 mm, 20.09°, 23.25°, 22.03°, 31.43°, 8.21° in group 2, respectively. There were significant differences in thoracic kyphosis (p=0.01) and lumbar lordosis (p=0.04) between the two groups. L1 slope was positively correlated with thoracic kyphosis (r=0.46, p=0.01), lumbar lordosis (r=0.51, p=0.01), and local kyphotic angle (r=0.29, p=0.04) in group 1. Conclusions: These results suggest that L1 slope is a central indicator for the evaluation of thoracolumbar sagittal balance in osteoporotic vertebral fractures.

Study Design: Case report. Objectives: This case report presents a surgical technique used to perform vertebral anterior column stabilization in an elderly male patient who had recently been diagnosed with an uppermost instrumented vertebral fracture (IVF) at the site of previous posterior lumbar instrumented fusion (PIF). Summary of Literature Review: Although conservative treatment is also used for IVF, the proximal junction of PIF is an area where the compression load is concentrated biomechanically, so the uppermost IVF often requires surgical treatment. This may require fixation of extended segments and more surgical morbidity. Materials and Methods: A 73-year-old male patient who had undergone PIF from L2 to L5 more than 20 years previously was recently diagnosed with uppermost IVF without a traumatic event. He complained of persistent back pain even after 2 months of conservative treatment. He ultimately underwent percutaneous vertebroplasty through the parapedicular approach. Result: The patients showed a favorable outcome at a 1-year follow-up. Conclusions: Percutaneous vertebroplasty through the parapedicular approach for uppermost IVF at the site of a previous PIF might be a feasible and less invasive alternative.