Comparative Analysis of Clinical Outcomes and Adjacent Level Angle Change on Single-level Lumbar 4-5 Fusion Using Percutaneous Screw Fixation and Open Screw Fixation

ABSTRACT

OBJECTIVE: Percutaneous pedicle screw fixation is one of treatment option in lumbar degenerative disease. The advantage of percutaneous pedicle screw fixation is to minimize iatrogenic injury of supporting structures in spine. This study compares clinical outcomes and radiologic changes in adjacent level of percutaneous pedicle screw fixation with those of open pedicle screw fixation. METHODS: Total 54 lumbar degenerative spine patients underwent screw fixation and interbody fusion after decompression. Percutaneous pedicle screw was used in 23 patients, other patients underwent open pedicle screw fixation. Patients' age, sex, diagnosis and, operative results were collected retrospectively. Clinical outcomes were measured by Visual Analogue Scale, Odom's criteria and Oswestry Disability Index. We measured lordotic angle and adjacent segment angle in follow-up radiologic study. RESULTS: Clinical outcomes showed no obvious differences in both percutaneous and open screw fixation groups. In radiologic finding, both groups revealed no significant differences in lordotic angles. On the other hand, L3-4 adjacent level angle change in open group was larger than in percutaneous group. The percutaneous group's sagittal angle changed from 10.2+/-2.4 to 11.6+/-2.7 in follow-up periods, and The open group's sagittal angle changed from 9.9+/-2.4 to 13.4+/-2.9. This difference has a statistical significance. But there is no significant difference in L5-S1 adjacent level angle change between two groups. CONCLUSION: We guess open screw fixation tend to make degenerative change in adjacent segment than percutaneous screw fixation. This suggestion may be related on minimal injury of supporting structures and preservation of adjacent facet joints in percutaneous screw fixation. But it can be confirmed through additional follow-up periods.