**Introduction:**
Spinal fixation has been regarded as the gold standard treatment for degenerative lumbar spondylolisthesis, demonstrating superior clinical outcomes compared to decompression procedures. Despite satisfactory outcome associated with fusion, adjacent segment disease (ASD) remains a long-term issue. To address these issue, instruments have been actively developed and the Graf system as dynamic non-fusion stabilization procedure was performed from 1992. However, the Graf system had limited applicability and its clinical outcome of degenerative lumber diseases were suboptimal, the utilization of stabilization procedures have decreasing. In stead of Graf system, our institution has embraced the Segmental Spinal Correction System (SSCS; Ulrich Medical, Ulm, Germany) from 2005. The SSCS has solid rod and pedicle screw that has mobility in its screw head. This system allows some motion in flexion and extension in sagittal plane. We have managed SSCS as dynamic non-fusion stabilization. This study was to demonstrate the comparison of SSCS and transforaminal lumbar interbody fusion (TLIF) over a minimum 10-year follow-up.
**Methods:**
A total 96 lumbar spinal canal stenosis patients with L4 degenerative spondylolisthesis (Meyerding classification grade Ⅰ) included in the study (minimum 10-year follow up). 57 patients were treated with TLIF (T group), and 39 patients were with SSCS (S group). Parameters evaluated included age, BMI, operating time, blood loss, ASD presence, and re-operation incidence. Postoperative ASD was defined as a reduction of over 3 mm in disc height or displacement of the vertebral body by over 3 mm in anterior or posterior direction or a motion increase of 5° or more on dynamic X-rays compared to preoperative images.
**Results:**
No statistically significant differences in age or BMI were discerned between the T and S groups. However, the S group exhibited significantly lower operation time and blood loss compared to the T group. 11 patients (19%) in group T and 9 patients (23%) in group S were underwent re-operation due to ASD. There is no differences between group T and S (p=0.654). Nevertheless, ASD incidence was notably lower in the S group (5 out of 30 cases, excluding re-operated 9 cases) than in the T group (25 out of 46 cases, excluding re-operated 11 cases) (chi-square test were used: p=0.001).
**Discussion:**
Although there is no significant difference in re-operation rates between fixation and stabilization surgeries, a lower incidence rate of ASD was observed in the S group. The unique sagittal plane mobility afforded by the SSCS's distinct screw head structure might potentially permit micro motion, acting as a shock absorber and preventing adjacent segment pathology. As for the lack of a predominant difference in the rate of re-operation, further study is needed due to the small number of cases. The result of this study demonstrated that for degenerative spondylolisthesis without intervertebral foraminal stenosis, dynamic non-fusion stabilization is less invasive than fusion and may be an effective alternative to conventional fusion.