Posterior Lumbar Interbody Fusion with Cage and Local Bone Graft in Spondylolisthesis: Unilateral-caged versus Bilateral-caged / 대한척추외과학회지

ABSTRACT

STUDY DESIGN: Retrospective, controlled study OBJECTIVE: To compare one and two-caged posterior lumbar interbody fusion (PLIF) with local bone grafting for spondylolisthesis. SUMMARY OF LITERATURE REVIEW Even though there are many reports on PLIF using cages and local bone grafting, Studies comparing one and two-caged PLIFs are rare. MATERIALS AND METHODS: Sixty-three patients who underwent pedicle screw fixated PLIF using cages and local bone grafts were followed for more than 1 year. Twenty-five patients had one cage (group I), and 38 patients had two cages (group II). Sampling error, disc height, sagittal Cobb angle, coronal Cobb angle, fusion rate, Oswestry disability index (ODI), operation time, blood loss, and neurologic complications were assessed. RESULTS: There was no sampling error between the two groups, except with regard to diagnosis degenerative spondylolisthesis, 15 cases in group I and 9 cases in group II; spondylolytic spondylolisthesis, 10 cases in group I and 29 cases in group II (p=0.004). Fusion rates were 87.5% and 88.2% for groups I and II, respectively (p=1.000). More disc height loss occurred in group I (0.6 mm) than in group II (0.0 mm) (p=0.041). Over-3mm-disc height-losses were noted more frequently in group I (20%) than in group II (2.6%) (p=0.022). ODI improved from 28.1 to 12.3 (72.1% improvement) in group I and from 29.2 to 12.7 (79.3% improvement) in group II. There were no significant differences in operation time, amount of blood loss, or neurologic complications between the two groups. CONCLUSION: Unilateral one-caged PLIF with local bone grafting and posterior instrumentation was no different from bilateral two-caged PLIF with regard to fusion rates or radiologic or clinical results. The statistically significant differences in disc height seemed to be clinically insignificant. Disc height loss of greater than 3 mm was much more common in group I, with one-caged PLIF.