Related Experiment Video
Updated: May 10, 2026

An Anesthesia, Surgery, and Harvest Method for the Evaluation of Transpedicular Screws Using an In Vivo Porcine Lumbar Spine Model
Published on: May 31, 2017
Risk factors for screw loosening in patients with lumbar degenerative spondylolisthesis treated with Dynesys dynamic
Yen-Chun Huang1,2, Hsi-Hsien Lin1,2, Shih-Tien Wang3
1School of Medicine, National Yang Ming Chiao Tung University, Taipei, Taiwan, ROC.
Background:
Posterior decompression with Dynesys dynamic stabilization (DDS) is an effective treatment option for degenerative spondylolisthesis. However, postoperative pedicle screw loosening (PSL) often results in poor outcomes. Determining possible risk factors may aid in making informed decisions. This study aimed to evaluate the incidence and risk factors for PSL in patients who underwent elective DDS.
Methods:
We conducted a retrospective analysis of 94 patients with L4-L5 grade I degenerative spondylolisthesis who underwent DSS at a single academic institution between May 2008 and February 2015. Screw loosening was defined as the presence of a halo or double-halo sign on plain radiography.
Results:
The rate of screw loosening was 4.8% among screws and 11.7% among patients. Multivariable analysis revealed that age >65 years, smoking, segmental range of motion (ROM) >13°, and L1 vertebral body Hounsfield unit <110 were risk factors for PSL after DDS. Five reoperations were performed; however, no instances of screw breakage were observed.
Conclusion:
Our study identified risk factors for PSL after DDS, including older age, smoking, larger preoperative segmental ROM, and lower L1 vertebral body HU, which could assist in preoperative decision-making and surgical planning.
More Related Videos
12:25C-arm-Free Simultaneous OLIF51 and Percutaneous Pedicle Screw Fixation in a Single Lateral Position
Published on: September 16, 2022
04:19Minimally Invasive Treatment for Thoracolumbar Burst Fracture Using Sagittal Alignment Screws and A Trauma Reduction Device
Published on: November 8, 2024
Related Concept Videos
Herniated Intervertebral Disc l: Introduction
Degenerative Disc Disease I: Introduction
Degenerative Disc Disease ll: Pathophysiology